JP2003181297A - Thin film-like photocatalyst, forming method thereof, method of treating hydrogen sulfide using the thin film- like photocatalyst, and method of manufacturing hydrogen - Google Patents

Thin film-like photocatalyst, forming method thereof, method of treating hydrogen sulfide using the thin film- like photocatalyst, and method of manufacturing hydrogen

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Publication number
JP2003181297A
JP2003181297A JP2001385517A JP2001385517A JP2003181297A JP 2003181297 A JP2003181297 A JP 2003181297A JP 2001385517 A JP2001385517 A JP 2001385517A JP 2001385517 A JP2001385517 A JP 2001385517A JP 2003181297 A JP2003181297 A JP 2003181297A
Authority
JP
Japan
Prior art keywords
thin film
hydrogen
photocatalyst
compound semiconductor
sulfide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2001385517A
Other languages
Japanese (ja)
Inventor
Kazuyuki Taji
和幸 田路
Atsuo Kasuya
厚生 粕谷
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Japan Science and Technology Agency
Original Assignee
Japan Science and Technology Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Japan Science and Technology Corp filed Critical Japan Science and Technology Corp
Priority to JP2001385517A priority Critical patent/JP2003181297A/en
Priority to PCT/JP2002/013136 priority patent/WO2003051512A1/en
Publication of JP2003181297A publication Critical patent/JP2003181297A/en
Pending legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B17/00—Sulfur; Compounds thereof
    • C01B17/02—Preparation of sulfur; Purification
    • C01B17/04—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides
    • C01B17/0495—Preparation of sulfur; Purification from gaseous sulfur compounds including gaseous sulfides by dissociation of hydrogen sulfide into the elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/06—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of zinc, cadmium or mercury
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J27/00—Catalysts comprising the elements or compounds of halogens, sulfur, selenium, tellurium, phosphorus or nitrogen; Catalysts comprising carbon compounds
    • B01J27/02—Sulfur, selenium or tellurium; Compounds thereof
    • B01J27/04—Sulfides
    • B01J35/39—
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
    • C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
    • C01B3/04—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of inorganic compounds, e.g. ammonia
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin film-like photocatalyst which acts on hydrogen sulfide to produce sulfur and hydrogen, and is convenient for handling. <P>SOLUTION: The thin film-like photocatalyst composed of a compound semiconductor is formed by dipping a base material 63 in a solution 62 containing chemical species to be a raw materials of the compound semiconductor and depositing and fixing the compound semiconductor on the surface of the base material 63 by chemical bath deposition (CBD) method. The thin film-like photocatalyst composed of ZnS, ZnO or the like is formed by using a complexing agent and a buffer agent selectively and dipping the base material into the solution containing the chemical species (for example, Zn) becoming a precursor to proceed a heterogeneous reaction between the solution and the surface of the base material in the CBD method. <P>COPYRIGHT: (C)2003,JPO

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、水素や硫黄などを
必要とする化学工業分野、脱硫工程などで発生した硫化
水素などを処理する化学工業分野、および悪臭物質や大
気汚染物質を除去する環境保全分野などで利用可能な薄
膜状光触媒、その作製方法、およびその使用方法に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of chemical industry that requires hydrogen and sulfur, the field of chemical industry that processes hydrogen sulfide generated in desulfurization processes, and the environment for removing odorous substances and air pollutants. The present invention relates to a thin film photocatalyst that can be used in the field of conservation, a method for producing the same, and a method for using the same.

【０００２】[0002]

【従来の技術】光触媒技術の応用は、環境汚染物質や悪
臭成分・雑菌などの分解など、様々な化学反応を促進す
る特性を利用した実用化が始まっている。その例として
は、病院の手術室などで利用される抗菌タイル、空気清
浄機やエア・コンディショナーのフィルタ、高速道路な
どの照明灯のガラスなどが挙げられる。これら光触媒の
酸化促進能力を利用した実用化の一方で、水などに光触
媒を作用させて水素を得ることや、炭酸ガスに作用させ
て炭素を固定還元することを目的とした研究も行われて
いる。2. Description of the Related Art The application of photocatalyst technology has begun to be put into practical use by utilizing the property of promoting various chemical reactions such as decomposition of environmental pollutants, malodorous components, and various bacteria. Examples include antibacterial tiles used in hospital operating rooms, filters for air purifiers and air conditioners, and glass for lighting in highways. While making practical use of these photocatalysts by utilizing their oxidation-promoting ability, research has also been carried out with the aim of acting hydrogen on photocatalysts such as water to obtain hydrogen, or by acting on carbon dioxide to fix and reduce carbon. There is.

【０００３】一方、化石エネルギー資源の枯渇や地球温
暖化による大気汚染など環境問題の観点から、クリーン
で安全なエネルギーの獲得技術および環境汚染物質の浄
化技術の確立が求められている。中でも光触媒の利用は
有望であり、例えば、光触媒を石油精製や金属精練の脱
硫工程に応用することが考えられる。On the other hand, from the viewpoint of environmental problems such as exhaustion of fossil energy resources and air pollution due to global warming, establishment of clean and safe energy acquisition technology and purification technology of environmental pollutants are required. Among them, the use of photocatalyst is promising, and for example, it can be considered that the photocatalyst is applied to the desulfurization step of petroleum refining and metal refining.

【０００４】現在、一般的に行われている原油の脱硫工
程を図３に示す。原油を蒸留する際に、重質ナフサを水
素化精製して原油に含まれる硫黄分を全て硫化水素に変
化させて回収している。さらに、ここで発生した硫化水
素は、図４に示すように、クラウス法と呼ばれるプロセ
スを経て、酸化して硫黄を回収している。このクラウス
法は、硫化水素の３分の１を酸化して亜硫酸ガスとし、
これと残りの硫化水素とを反応させて硫黄とするプロセ
スである。すなわち、化学式では以下のように表され
る。FIG. 3 shows a crude oil desulfurization process which is generally performed at present. When distilling crude oil, the heavy naphtha is hydrorefined and all the sulfur content in the crude oil is converted to hydrogen sulfide for recovery. Further, as shown in FIG. 4, the hydrogen sulfide generated here is oxidized by a process called a Claus method to recover sulfur. This Claus method oxidizes one-third of hydrogen sulfide into sulfurous acid gas,
This is a process in which this is reacted with the remaining hydrogen sulfide to form sulfur. That is, the chemical formula is represented as follows.

【０００５】[0005]

【化１】２Ｈ２Ｓ ＋ ３Ｏ２ → ２Ｈ２Ｏ ＋ ２ＳＯ２ ４Ｈ２Ｓ ＋ ２ＳＯ２ → ４Ｈ２Ｏ＋ ６ＳEmbedded image 2H 2 S + 3O 2 → 2H 2 O + 2SO 2 4H 2 S + 2SO 2 → 4H 2 O + 6S

【０００６】この硫黄回収工程は、亜硫酸ガスと硫化水
素の触媒反応だけでなく、加熱や凝集を繰り返すため、
膨大なエネルギーを要している。また、亜硫酸ガスの管
理にコストがかかるなどの問題を有している。In this sulfur recovery step, not only the catalytic reaction of sulfurous acid gas and hydrogen sulfide but also heating and agglomeration are repeated,
It requires a huge amount of energy. In addition, there is a problem that the cost of managing the sulfurous acid gas is high.

【０００７】図３に示した原油の脱硫工程の重質ナフサ
の水素化生成には水素ガスが用いられるが、その水素ガ
ス製造方法の１つは図５に示す方法である。図５に示す
水素ガス製造方法は、深冷水素精製法もしくは窒素洗浄
法と呼ばれ、水素に富んだガスから水素を生成するもの
で、前述の炭化水素分解以外の工程から生成する粗ガス
にも適用できる。Hydrogen gas is used for hydrogenation of heavy naphtha in the desulfurization step of crude oil shown in FIG. 3, and one of the hydrogen gas production methods is the method shown in FIG. The hydrogen gas production method shown in FIG. 5 is called a cryogenic hydrogen purification method or a nitrogen cleaning method, and produces hydrogen from a gas rich in hydrogen. Can also be applied.

【０００８】この製造方法では、原料ガスを圧縮し、水
酸化ナトリウムで洗浄して炭酸ガス、硫化水素などをま
ず除去する。次に、熱交換器で低温の精製水素ガスによ
って冷却し、メタン及びＣ４以上の炭化水素ガスを液化
除去する。ついで、窒素洗浄塔において塔底から塔頂へ
上昇させて塔頂から下降する液化窒素によって洗浄する
ことによって、一酸化炭素及び窒素が液状で塔底から排
出され、精製分離された水素が塔頂から取り出される。In this manufacturing method, the raw material gas is compressed and washed with sodium hydroxide to first remove carbon dioxide, hydrogen sulfide and the like. Next, it is cooled by a low-temperature purified hydrogen gas in a heat exchanger to liquefy and remove methane and C4 or higher hydrocarbon gas. Then, in a nitrogen washing tower, by raising from the bottom to the top of the tower and washing with liquefied nitrogen descending from the top, carbon monoxide and nitrogen are discharged in liquid form from the bottom, and purified and separated hydrogen is added to the top. Taken from.

【０００９】これらの水素製造方法では、主に硫化水素
などの硫黄化合物による触媒の被毒を避けるための精製
工程を必要とし、また加熱や凝集を繰り返すために膨大
なエネルギーを要している。These hydrogen production methods require a refining step for avoiding poisoning of the catalyst mainly by sulfur compounds such as hydrogen sulfide, and enormous energy is required for repeating heating and agglomeration.

【００１０】[0010]

【発明が解決しようとする課題】上述したように、従来
の硫化水素処理方法や水素製造方法では、加熱や凝集を
繰り返すために膨大なエネルギーを必要としている。し
たがって、簡便に硫化水素から硫黄と水素を取り出すこ
とができれば、硫化水素の処理と水素の製造とを同時に
行うことができ、従来の硫化水素処理方法及び水素製造
方法の問題を解決することができる。さらに、取り出し
た水素を脱硫工程に使用することで、有用なケミカル・
リサイクルを実現することができる。また、太陽光の波
長のほぼ全域で作用する光触媒であれば、有効に太陽エ
ネルギーを利用できる。As described above, in the conventional hydrogen sulfide treatment method and hydrogen production method, enormous energy is required to repeat heating and agglomeration. Therefore, if sulfur and hydrogen can be easily extracted from hydrogen sulfide, the treatment of hydrogen sulfide and the production of hydrogen can be simultaneously performed, and the problems of the conventional hydrogen sulfide treatment method and hydrogen production method can be solved. . Furthermore, by using the extracted hydrogen in the desulfurization process, a useful chemical
Recycling can be realized. Further, if the photocatalyst acts in almost all wavelengths of sunlight, solar energy can be effectively used.

【００１１】本発明は、上記従来技術の問題点に対処し
てなされたもので、硫化水素から水素を生成することが
できる化合物半導体による薄膜状光触媒と、その作製方
法を提供することを目的とする。また、本発明は、上記
薄膜状光触媒を用いて硫化水素から水素を効率よく回収
することができる硫化水素の処理方法および水素の製造
方法を提供することを目的とする。The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a thin film photocatalyst made of a compound semiconductor capable of producing hydrogen from hydrogen sulfide and a method for producing the same. To do. Another object of the present invention is to provide a method for treating hydrogen sulfide and a method for producing hydrogen, which are capable of efficiently recovering hydrogen from hydrogen sulfide using the thin film photocatalyst.

【００１２】[0012]

【課題を解決するための手段】即ち、請求項１に係る薄
膜状光触媒は、基材上に化合物半導体よりなる層が固定
化され、該化合物半導体は酸素原子を含むことを特徴と
する。ここで、化合物半導体としては、金属硫化物であ
ることが好ましい。That is, the thin-film photocatalyst according to claim 1 is characterized in that a layer made of a compound semiconductor is immobilized on a substrate, and the compound semiconductor contains an oxygen atom. Here, the compound semiconductor is preferably a metal sulfide.

【００１３】またその作製方法は、化合物半導体原料と
なる化学種を含む溶液中に基材を浸漬し、化学浴槽析出
法（ＣＢＤ法）により前記基材表面に化合物半導体を析
出・固定化させてなることを特徴とする。Further, the manufacturing method is as follows: the base material is immersed in a solution containing a chemical species to be a compound semiconductor raw material, and the chemical compound is deposited and immobilized on the surface of the base material by a chemical bath deposition method (CBD method). It is characterized by

【００１４】ここで、該化合物半導体はII−VI族化合物
半導体であることが好ましく、特に金属硫化物であるこ
とが望ましい。さらには、硫化亜鉛または硫化カドミウ
ムであることが特に望ましい。Here, the compound semiconductor is preferably a II-VI group compound semiconductor, and particularly preferably a metal sulfide. Furthermore, zinc sulfide or cadmium sulfide is particularly desirable.

【００１５】本発明では、光触媒を基材上に薄膜状に形
成することによって、粒子状よりもハンドリング性に優
れ、実用化の可能な光触媒とすることができる。また、
少量の触媒によって広い面積を持つ光触媒が生成でき
る。In the present invention, by forming the photocatalyst in the form of a thin film on the base material, the photocatalyst can be made more practical than particles and can be put to practical use. Also,
A photocatalyst with a large area can be produced with a small amount of catalyst.

【００１６】また、粒子状のように溶液中に分散せず基
材上に固定されているために、照射角を最適な角度にす
ることで照射光を受けてその光エネルギーを変換する効
率を向上させることができる。Further, since the particles are not dispersed in the solution and are fixed on the substrate as in the case of particles, the efficiency of receiving the irradiation light and converting the light energy can be improved by setting the irradiation angle to the optimum angle. Can be improved.

【００１７】ここでＣＢＤ法とは、前駆体となる化学種
を含む溶液に基材を浸し、溶液と基材表面との間で不均
一反応を進行させることによって薄膜を基材上に析出さ
せるという方法である。この手法は図６に見るように複
雑な装置を必要とせず、比較的低温条件での薄膜作製が
可能である。また、溶液組成を制御することにより所望
の薄膜を得ることができ、基材に対する薄膜の化学吸着
という強い結合が期待できる。Here, the CBD method is to deposit a thin film on a substrate by immersing the substrate in a solution containing a chemical species as a precursor and causing a heterogeneous reaction between the solution and the surface of the substrate. Is the method. This method does not require a complicated device as shown in FIG. 6 and can form a thin film under a relatively low temperature condition. In addition, a desired thin film can be obtained by controlling the solution composition, and strong bonding such as chemisorption of the thin film to the substrate can be expected.

【００１８】ＺｎＳおよびＺｎＯの薄膜作製は、従来Ｃ
ＢＤ法による析出は困難とされていたが、本発明におい
て以下に述べるように、ＮＨ３およびＮ２Ｈ４を錯化剤
として用い、（ＮＨ４）２ＳＯ４を緩衝剤として用いる
ことによって作製可能であることを確認した。ZnS and ZnO thin films have been produced by conventional C
Although precipitation by the BD method was considered to be difficult, it was prepared by using NH 3 and N 2 H 4 as complexing agents and (NH 4 ) 2 SO 4 as a buffering agent, as described below in the present invention. I confirmed that it is possible.

【００１９】ＣＢＤ（Ｃｈｅｍｉｃａｌ Ｂａｔｈ Ｄ
ｅｐｏｓｉｔｉｏｎ、化学析出）法における溶液から化
合物を析出させる核生成反応では、新しい相の核が均一
な相の中に孤立して形成される場合よりも、不均一な部
分が存在してそこに核生成が起きる方が、新しい相の核
形成に必要な界面エネルギーが小さいことが知られてい
る（不均一核形成）。この不均一核生成を利用して、何
らかの方法で溶液中のイオン濃度を飽和以下にし、基材
上に選択的に析出を起こさせるＣＢＤ法は、他の薄膜析
出法と比べて以下のような利点がある。CBD (Chemical Bath D)
In the nucleation reaction for precipitating a compound from a solution in the (eposition, chemical deposition) method, a heterogeneous portion exists and nuclei exist in the nuclei of a new phase, as compared with the case where the nuclei of a new phase are isolated and formed in a homogeneous phase. It is known that the interfacial energy required for nucleation of a new phase is smaller when the formation occurs (heterogeneous nucleation). Utilizing this heterogeneous nucleation, the CBD method in which the ion concentration in the solution is saturated below a certain level to cause selective precipitation on the substrate is as follows compared with other thin film deposition methods. There are advantages.

【００２０】即ち、装置が簡単であること、蒸着法など
に比べて、低温（室温近く）で析出させることができる
こと、低コストで大きな面積に対しても同じように適用
できること、および用途に適合した様々な基材に析出さ
せることができることである。That is, the apparatus is simple, the deposition can be performed at a low temperature (close to room temperature) as compared with the vapor deposition method, the cost can be similarly applied to a large area, and the application can be adapted. That is, it can be deposited on various substrates.

【００２１】本発明の薄膜状光触媒において、基材とし
てはシリコン、ガラス、ニッケル、亜鉛、白金、樹脂な
どからなる基材が考えられる。このうち金属が望まし
く、特に白金が望ましい。また、上記光触媒の材料を有
効に析出して固定化できる材料であれば他の基材でも可
能である。In the thin film photocatalyst of the present invention, the base material may be a base material made of silicon, glass, nickel, zinc, platinum, resin or the like. Of these, metals are preferable, and platinum is particularly preferable. Further, other materials can be used as long as they can effectively deposit and fix the photocatalyst material.

【００２２】薄膜の膜厚は、ＺｎＳの場合、５〜１００
ｎｍが好ましく、ＣｄＳの場合は２００〜５００ｎｍが
好ましい。薄膜は単一成分からなる単一膜であっても、
あるいは複数の成分からなる単一膜であっても良く、さ
らに単層膜でも多層膜であっても良い。また構成成分を
厚さ方向に連続的に変化させた薄膜とすることも可能で
ある。The thickness of the thin film is 5 to 100 for ZnS.
nm is preferable, and in the case of CdS, 200 to 500 nm is preferable. Even if the thin film is a single film composed of a single component,
Alternatively, it may be a single film composed of a plurality of components, and may be a single layer film or a multilayer film. It is also possible to form a thin film in which the constituent components are continuously changed in the thickness direction.

【００２３】薄膜の構成成分を変化させるには、例え
ば、基材上に化合物半導体を析出させるための溶媒を変
化させることによって可能となる。１例として挙げるな
らば、溶媒にＺｎＳＯ４、ＳＣ（ＮＨ２）２、ＮＨ３、
Ｎ２Ｈ４、（ＮＨ４）２ＳＯ４を用いるとＺｎＳが析出
し易くなり、ＺｎＳＯ４、ＳＣ（ＮＨ２）２、ＮＨ３だ
けの場合はＺｎＯが析出し易くなる。それ故、この２種
類の溶液を用いてその比率を変化させながら析出させる
ことによって、基材の側にＺｎＯを多く析出させ、基材
から離れた表面の側にＺｎＳを多く析出させることが可
能となる。The constituent components of the thin film can be changed, for example, by changing the solvent for depositing the compound semiconductor on the base material. As one example, the solvent may be ZnSO 4 , SC (NH 2 ) 2 , NH 3 ,
When N 2 H 4 and (NH 4 ) 2 SO 4 are used, ZnS is easily deposited, and when only ZnSO 4 , SC (NH 2 ) 2 and NH 3 are used, ZnO is easily deposited. Therefore, it is possible to deposit a large amount of ZnO on the side of the base material and a large amount of ZnS on the side of the surface away from the base material by using these two types of solutions and precipitating while changing the ratio. Becomes

【００２４】請求項７に記載の薄膜状光触媒の使用方法
は、基材上に化合物半導体よりなる層が固定化された薄
膜状光触媒を、硫化水素を溶解させた溶液中に浸漬して
水素と硫黄を回収することを特徴とする。According to the method of using the thin film photocatalyst of claim 7, the thin film photocatalyst in which a layer made of a compound semiconductor is fixed on a substrate is immersed in a solution in which hydrogen sulfide is dissolved to form hydrogen gas. Characterized by recovering sulfur.

【００２５】化合物半導体層からなる薄膜状の光触媒
は、特に硫化水素を溶解させたアルカリ性溶液に該薄膜
状の光触媒を浸漬することで、高活性な光触媒の酸化還
元作用により硫化水素から硫黄と水素を回収することが
できる。The thin-film photocatalyst comprising a compound semiconductor layer is prepared by immersing the thin-film photocatalyst in an alkaline solution in which hydrogen sulfide is dissolved. Can be recovered.

【００２６】この薄膜状光触媒による硫化水素の処理方
法は、（１）アルカリ性の溶液に硫化水素を溶解する工
程、（２）硫化水素を溶解させた溶液に該薄膜状の光触
媒を浸漬し、可視光・紫外線等の光を照射して水素ガス
を回収する工程、（３）水素ガス回収後の溶液から硫黄
を回収し、硫黄回収後の溶液を硫化水素を溶解する溶液
として（１）の工程に再循環する工程とで構成すること
ができる。各工程の反応式は次式で表される。The method of treating hydrogen sulfide with this thin film photocatalyst is as follows: (1) a step of dissolving hydrogen sulfide in an alkaline solution; (2) immersing the thin film photocatalyst in a solution in which hydrogen sulfide is dissolved, A step of recovering hydrogen gas by irradiating light such as light or ultraviolet ray, (3) a step of recovering sulfur from the solution after recovering the hydrogen gas, and using the solution after recovering the sulfur as a solution for dissolving hydrogen sulfide And a step of recirculating the same. The reaction formula of each step is represented by the following formula.

【００２７】[0027]

【化２】（１）Ｈ２Ｓ → Ｈ＋ ＋ ＨＳ− （２）２ＨＳ− → Ｈ２ ＋ Ｓ２ ２− （３）Ｓ２ ２− → Ｓ２− ＋ Ｓ(1) H 2 S → H ++ + HS − (2) 2HS − → H 2 + S 2 2− (3) S 2 2 2 → → S 2 − + S

【００２８】薄膜状光触媒による水溶液からの水素発生
効率は、微粒子状の光触媒の場合に比較して、はるかに
大きくなる。その原因は、光触媒を薄膜状で固定化して
使用することにより、薄膜表面に適当な凹凸が存在して
大きな表面積を持つこと、そして微細な触媒粒子が基材
上に固定化されているために照射光を受けてそのエネル
ギーを水素発生に変換する効率が改善されたためと考え
られる。The efficiency of hydrogen generation from an aqueous solution by a thin film photocatalyst is much higher than that of a fine particle photocatalyst. The reason for this is that by using the photocatalyst as a thin film, it has a large surface area with appropriate irregularities on the surface of the thin film, and because the fine catalyst particles are fixed on the substrate. It is considered that the efficiency of receiving the irradiation light and converting the energy into hydrogen generation was improved.

【００２９】請求項１０に記載の薄膜状光触媒を用いた
水素の製造方法は、基材上に化合物半導体よりなる層が
固定化された薄膜状光触媒を、硫化水素を溶解させた溶
液中に浸漬して水素を製造することを特徴とする。この
水素製造方法は、既に述べた硫化水素の処理方法と同様
であり、その際に産出される水素を回収して水素を製造
する。この方法によると、水素を簡便に製造することが
可能となる。In the method for producing hydrogen using the thin film photocatalyst according to claim 10, the thin film photocatalyst in which a layer made of a compound semiconductor is fixed on a substrate is immersed in a solution in which hydrogen sulfide is dissolved. To produce hydrogen. This method for producing hydrogen is similar to the method for treating hydrogen sulfide already described, and hydrogen produced at that time is recovered to produce hydrogen. According to this method, hydrogen can be easily produced.

【００３０】[0030]

【発明の実施の形態】以下、本発明にかかる化合物半導
体による薄膜状光触媒、その作製方法、およびその薄膜
状光触媒を用いた硫化水素の処理方法と水素の製造方法
の実施の形態を説明する。 第１の実施の形態（請求項１、請求項４） 本発明にかかる薄膜状光触媒の作製方法は、化合物半導
体の原料となる化学種を含む溶液中に基材を浸漬し、Ｃ
ＢＤ法により基材表面に化合物半導体を析出・固定化さ
せる。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a thin film photocatalyst using a compound semiconductor, a method for producing the same, a method for treating hydrogen sulfide and a method for producing hydrogen using the thin film photocatalyst according to the present invention will be described below. First Embodiment (Claims 1 and 4) A method for producing a thin film photocatalyst according to the present invention comprises immersing a base material in a solution containing a chemical species as a raw material of a compound semiconductor, and applying C
The compound semiconductor is deposited and fixed on the surface of the base material by the BD method.

【００３１】ＣＢＤ法は、前駆体となる化学種を含む溶
液に基材を浸し、溶液と基材表面との間で不均一反応を
進行させることによって薄膜を基材上に選択的に析出さ
せる方法である。この手法は、図６に示すような装置を
用いて行うことができ、複雑な装置を必要とせず、比較
的低温での薄膜作製が可能である。図６はＣＢＤ法によ
る薄膜状光触媒の作製装置を示す模式的斜視図である。
図中、６１は熱撹拌機、６２は反応溶液、６３は基材、
６４は磁気攪拌子、そして６５は基材をつるす糸であ
る。In the CBD method, a substrate is immersed in a solution containing a precursor chemical species, and a heterogeneous reaction is allowed to proceed between the solution and the substrate surface to selectively deposit a thin film on the substrate. Is the way. This method can be performed by using an apparatus as shown in FIG. 6, does not require a complicated apparatus, and can form a thin film at a relatively low temperature. FIG. 6 is a schematic perspective view showing an apparatus for producing a thin film photocatalyst by the CBD method.
In the figure, 61 is a thermal stirrer, 62 is a reaction solution, 63 is a base material,
64 is a magnetic stirrer, and 65 is a thread for suspending the base material.

【００３２】ＣＢＤ法による薄膜析出条件は、予め別途
作製した粒子を基材に付着させる場合と異なり精密な条
件が要求されると考えられる。以下にその条件を考察す
る。まず、前駆物質の濃度について考える。目的となる
化合物を生成させるにはその前駆物質、即ち陽イオンと
陰イオンが反応溶液中に存在していればよいことは明ら
かであるが、例えばIt is considered that the conditions for depositing a thin film by the CBD method require precise conditions, unlike the case where particles prepared separately beforehand are attached to a substrate. The conditions are considered below. First, consider the concentration of the precursor. It is clear that the precursors, that is, the cation and the anion, may be present in the reaction solution in order to form the target compound.

【００３３】[0033]

【化３】ａＸｍ＋＋ｂＹｎ−→ＸａＹｂ Embedded image aX m + + bY n− → X a Y b

【００３４】なる反応式に従ってＸｍ＋イオンと Ｙ
ｎ−イオンから化合物ＸａＹｂが生成する場合を考える
と、イオン濃度の積が溶解度積を上回る条件、即ち、溶
解度積をＫｓｐとして、X m + ions and Y according to the reaction formula
Considering the case where the compound X a Y b is produced from the n- ion, the condition where the product of the ion concentrations exceeds the solubility product, that is, the solubility product is K sp ,

【００３５】[0035]

【数１】 ［Ｘｍ＋］ａ［Ｙｎ−］ｂ＞Ｋｓｐ………（１）## EQU1 ## [X m + ] a [Y n- ] b > K sp ... (1)

【００３６】なる条件を満たすとき、溶液は飽和状態と
なり化合物は均一反応によって溶液中に生成する、いわ
ゆる沈殿が生じる。一方、イオン濃度積が溶解度積を下
回る条件、即ちWhen the above condition is satisfied, the solution becomes saturated and the compound is formed in the solution by a homogeneous reaction, so-called precipitation occurs. On the other hand, the condition that the ion concentration product is lower than the solubility product, that is,

【００３７】[0037]

【数２】 ［Ｘｍ＋］ａ［Ｙｎ−］ｂ＜Ｋｓｐ………（２）## EQU00002 ## [X m + ] a [Y n- ] b <K sp ... (2)

【００３８】なる条件を満たすとき、溶液は不飽和状態
のため化合物は生成しない。従って基材上に薄膜を析出
させるには溶液中沈殿物が生成しないような前駆物質濃
度条件、即ち（２）式を満足することが必要である。と
ころがイオン濃度積が溶解度積を大きく下回る条件下で
は、溶液中には当然のこと、基材上にも析出しない。そ
れ故できるだけ飽和に近い不飽和状態に保つことが望ま
しい。When the following condition is satisfied, the compound is not formed because the solution is in an unsaturated state. Therefore, in order to deposit a thin film on the substrate, it is necessary to satisfy the condition of the precursor concentration such that a precipitate is not formed in the solution, that is, the equation (2). However, under the condition that the ion concentration product is much lower than the solubility product, it naturally does not precipitate in the solution even on the substrate. Therefore, it is desirable to keep the unsaturated state as close to saturation as possible.

【００３９】次に、基材表面を活性化処理することも、
薄膜形成に有効である。基材を活性にする方法として
は、強酸、あるいは強アルカリによる基材のエッチング
や加熱、超音波の印加などが挙げられる。以上のことか
ら、溶液反応における良好な薄膜の生成は、溶液が飽和
に近い不飽和状態で活性な基材を用いることにより、不
均一反応を起こさせることによって実現する。Next, the surface of the base material may be activated.
Effective for thin film formation. Examples of the method for activating the base material include etching and heating of the base material with a strong acid or strong alkali, and application of ultrasonic waves. From the above, the formation of a good thin film in a solution reaction is realized by causing a heterogeneous reaction by using an active base material in an unsaturated state where the solution is close to saturation.

【００４０】第２の実施の形態（請求項７） 本発明にかかる硫化水素の処理方法は、基材上に化合物
半導体よりなる層が固定化された薄膜状光触媒を、硫化
水素を溶解させた溶液中に浸漬して水素と硫黄を回収す
ることを特徴とする。Second Embodiment (Claim 7) In the method for treating hydrogen sulfide according to the present invention, hydrogen sulfide is dissolved in a thin film photocatalyst in which a layer made of a compound semiconductor is immobilized on a substrate. It is characterized in that it is immersed in a solution to recover hydrogen and sulfur.

【００４１】図７は、本発明にかかる薄膜状光触媒を使
って硫化水素を処理する方法の一実施の形態を説明する
ための処理システムを概略的に示している。この処理シ
ステムは、硫化水素を溶解する硫化水素溶解槽１と、硫
化水素を溶解した溶液から水素ガスを回収する光触媒反
応槽３と、水素ガス回収後の溶液から硫黄を回収し、硫
黄回収後の溶液を硫化水素溶解槽１へリサイクルする硫
黄回収槽５とで構成されている。FIG. 7 schematically shows a treatment system for explaining an embodiment of a method for treating hydrogen sulfide using the thin film photocatalyst according to the present invention. This processing system includes a hydrogen sulfide dissolution tank 1 that dissolves hydrogen sulfide, a photocatalytic reaction tank 3 that recovers hydrogen gas from a solution in which hydrogen sulfide is dissolved, and sulfur from the solution after hydrogen gas recovery, and sulfur recovery after recovery. And a sulfur recovery tank 5 for recycling the solution of 1 to the hydrogen sulfide dissolution tank 1.

【００４２】上記構成において、硫化水素溶解槽１はア
ルカリ性の溶液を収容し、この中に硫化水素ガスが導入
され、溶解される。In the above structure, the hydrogen sulfide dissolution tank 1 contains an alkaline solution, and the hydrogen sulfide gas is introduced and dissolved therein.

【００４３】アルカリ性の溶液は、硫化水素の溶解・解
離と反応の場の提供を行うだけで、それ自体の変化は起
こらない。ここでは水酸化ナトリウム水溶液を例に挙げ
て説明するが、硫化水素を溶解・解離させるアルカリ性
溶液であれば利用可能である。The alkaline solution only dissolves and dissociates hydrogen sulfide and provides a field for reaction, and does not change itself. Here, an aqueous solution of sodium hydroxide will be described as an example, but any alkaline solution that dissolves and dissociates hydrogen sulfide can be used.

【００４４】硫化水素溶解槽１内において、水酸化ナト
リウム水溶液に硫化水素ガスが混入されると、次式に示
すような中和反応が起こり、硫化水素ガスは水酸化ナト
リウム水溶液に溶解し、硫化ナトリウム溶液となる。In the hydrogen sulfide dissolution tank 1, when hydrogen sulfide gas is mixed with the sodium hydroxide aqueous solution, a neutralization reaction as shown by the following equation occurs, and the hydrogen sulfide gas is dissolved in the sodium hydroxide aqueous solution to form a sulfurized gas. It becomes a sodium solution.

【００４５】[0045]

【化４】 ２ＮａＯＨ ＋ Ｈ２Ｓ → Ｎａ２Ｓ ＋ ２Ｈ２ＯEmbedded image 2NaOH + H 2 S → Na 2 S + 2H 2 O

【００４６】硫化ナトリウム溶液は光触媒反応槽３に送
られ、ここでは本発明にかかる薄膜状光触媒が浸漬さ
れ、光源７からの光（可視光および／または紫外線）が
照射されると、次式に示すように、水素ガスとポリ硫化
物イオンが生成し、水素ガスが回収される。The sodium sulfide solution is sent to the photocatalyst reaction tank 3, where the thin film photocatalyst according to the present invention is dipped and irradiated with light (visible light and / or ultraviolet light) from the light source 7, As shown, hydrogen gas and polysulfide ions are produced, and the hydrogen gas is recovered.

【００４７】[0047]

【化５】２Ｓ２− → Ｓ２ ２− ＋ ２ｅ− ２Ｈ＋ ＋ ２ｅ− → Ｈ２↑[Chemical Formula 5] 2S 2− → S 2 2− + 2e − 2H + + 2e − → H 2 ↑

【００４８】この溶液系にて硫化水素の溶解と水素発生
を続けると、ポリ硫化物イオンはその溶解度を越えてし
まい、ついには不均化反応（自己酸化還元反応）を起こ
して、次式に示すように、硫黄と硫化物イオンに変化す
る。When the dissolution of hydrogen sulfide and the generation of hydrogen are continued in this solution system, the polysulfide ion exceeds its solubility, and finally a disproportionation reaction (autooxidation-reduction reaction) occurs, and As shown, it transforms into sulfur and sulfide ions.

【００４９】[0049]

【化６】Ｓ２ ２− → Ｓ２− ＋ ＳEmbedded image S 2 2− → S 2− + S

【００５０】硫黄回収槽５では、上記不均化反応を利用
してポリ硫化物イオンを硫黄として回収する。硫黄を回
収された溶液は水酸化ナトリウムに戻るため、硫化水素
を溶解するための溶液として再利用される。In the sulfur recovery tank 5, polysulfide ions are recovered as sulfur by utilizing the above disproportionation reaction. The solution from which sulfur has been recovered returns to sodium hydroxide and is reused as a solution for dissolving hydrogen sulfide.

【００５１】上記の説明からも明らかなように、本実施
の形態においては、薄膜状光触媒によって硫化水素を分
解することで、クラウス法と同様に硫黄を回収すること
ができ、しかも脱硫工程で消費される水素を製造するこ
とができる。さらに、この硫化水素処理方法では、クラ
ウス法のような加熱及び凝集など多くのエネルギーを必
要とする操作を省くことができ、しかも硫化水素よりも
さらに危険な亜硫酸ガスが関与しないという点で優れて
いる。As is clear from the above description, in the present embodiment, by decomposing hydrogen sulfide by the thin film photocatalyst, it is possible to recover sulfur as in the Claus method and consume it in the desulfurization step. Hydrogen can be produced. Furthermore, in this hydrogen sulfide treatment method, it is possible to omit an operation that requires a lot of energy such as heating and agglomeration, such as the Claus method, and is excellent in that sulfurous acid gas, which is more dangerous than hydrogen sulfide, is not involved. There is.

【００５２】第３の実施の形態（請求項１０） 本発明にかかる水素の製造方法は、基材上に化合物半導
体よりなる層が固定化された薄膜状光触媒を、硫化水素
を溶解させた溶液中に浸漬して水素を製造することを特
徴とする。本実施の形態については、上述の硫化水素の
処理方法の一部分に既に含まれている。Third Embodiment (Claim 10) A method for producing hydrogen according to the present invention is a solution in which hydrogen sulfide is dissolved in a thin film photocatalyst in which a layer made of a compound semiconductor is immobilized on a substrate. It is characterized in that it is immersed in it to produce hydrogen. This embodiment is already included in a part of the above-mentioned hydrogen sulfide treatment method.

【００５３】[0053]

【実施例】実施例１〜５ ＺｎＳおよびＺｎＯの薄膜作製は、従来ＣＢＤ法による
析出は困難とされていたが、本発明において、ＮＨ３お
よびＮ２Ｈ４を錯化剤として、（ＮＨ４）２ＳＯ４を緩
衝剤として用いることによって作製可能となることが分
かった。EXAMPLES Examples 1 to 5 Although it has been conventionally difficult to deposit ZnS and ZnO thin films by the CBD method, in the present invention, NH 3 and N 2 H 4 are used as complexing agents (NH 4 ) It was found that it can be prepared by using 2 SO 4 as a buffer.

【００５４】最初に、ＺｎＳ薄膜の作製について説明す
る。まず、Ｚｎの前駆物質として硫酸亜鉛７水和物（Ｚ
ｎＳＯ４・７Ｈ２Ｏ）を０．００９ｍｏｌ／ｌ、Ｓの前
駆物質としてチオ尿素（ＳＣ（ＮＨ２）２）０．００９
ｍｏｌ／ｌ、錯化剤としてアンモニア水溶液（ＮＨ３）
０．５ｍｏｌ／ｌおよびヒドラジン１水和物（Ｎ２Ｈ４
・Ｈ２Ｏ）１．０ｍｏｌ／ｌ、緩衝剤として硫酸アンモ
ニウム（（ＮＨ４）２ＳＯ４）０．０２５ｍｏｌ／ｌを
準備する。以上の試薬を用いる場合の生成機構は次のよ
うになると考えられる。First, the production of a ZnS thin film will be described. First, zinc sulfate heptahydrate (Z
nSO 4 · 7H 2 O) of 0.009 mol / l, thiourea as a precursor S (SC (NH 2) 2 ) 0.009
mol / l, aqueous ammonia solution (NH 3 ) as a complexing agent
0.5 mol / l and hydrazine monohydrate (N 2 H 4
· H 2 O) 1.0mol / l , to prepare the ammonium sulfate ((NH 4) 2 SO 4 ) 0.025mol / l as a buffering agent. The generation mechanism using the above reagents is considered to be as follows.

【００５５】[0055]

【化７】［Ｚｎ（ＮＨ３）４］２＋＋ＳＣ（ＮＨ２）２
＋２ＯＨ−［Substrate］→ＺｎＳ（film）＋４ＮＨ３
＋ＣＨ２Ｎ２＋２Ｈ２ＯEmbedded image [Zn (NH 3 ) 4 ] 2+ + SC (NH 2 ) 2
+ 2OH − [Substrate] → ZnS (film) + 4NH 3
+ CH 2 N 2 + 2H 2 O

【００５６】反応経路を順に追うと次のようになる。ま
ずＺｎ２ ＋はＮＨ３と錯体を形成する。The reaction paths are sequentially followed as follows. First, Zn 2 + forms a complex with NH 3 .

【００５７】[0057]

【化８】 Ｚｎ２＋＋４ＮＨ３←→［Ｚｎ（ＮＨ３）４］２＋ Embedded image Zn 2+ + 4NH 3 ← → [Zn (NH 3 ) 4 ] 2+

【００５８】次に、ＮＨ３およびＮ２Ｈ４は加水分解を
起こしＯＨ−を生成する。Next, NH 3 and N 2 H 4 undergo hydrolysis to produce OH − .

【００５９】[0059]

【化９】ＮＨ３＋Ｈ２Ｏ←→ＮＨ４ ＋＋ＯＨ− Ｎ２Ｈ４＋Ｈ２Ｏ←→Ｎ２Ｈ５ ＋＋ＯＨ− Embedded image NH 3 + H 2 O ← → NH 4 + + OH − N 2 H 4 + H 2 O ← → N 2 H 5 + + OH −

【００６０】ＯＨ−は単体あるいはＺｎ（ＯＨ）２を形
成して基材に吸着し、また一方ＳＣ（ＮＨ２）２の加水
分解反応を起こす。OH − forms a simple substance or Zn (OH) 2 and is adsorbed to the base material, while causing a hydrolysis reaction of SC (NH 2 ) 2 .

【００６１】[0061]

【化１０】Ｚｎ２＋＋２ＯＨ−←→Ｚｎ（ＯＨ）２ ＳＣ（ＮＨ２）２＋２ＯＨ−→Ｓ２−＋ＣＨ２Ｎ２＋２
Ｈ２ＯEmbedded image Zn 2+ + 2OH − ← → Zn (OH) 2 SC (NH 2 ) 2 + 2OH − → S 2 − + CH 2 N 2 +2
H 2 O

【００６２】この反応によって生成したＳ２−がＺｎ
（ＯＨ）２と結びついてＺｎＳの薄膜が形成されると考
える。S 2− produced by this reaction is Zn
It is considered that a ZnS thin film is formed in association with (OH) 2 .

【００６３】さらに以上の試薬とそれらの濃度条件は、
錯化剤を用いることにより溶液中にフリーに存在してい
るＺｎ２＋の濃度を減少させ、緩衝剤を用いることによ
りＯＨ−の濃度を減少させているので、イオン濃度積が
溶解度積を下回り、さらには硫化ナトリウムＮａ２Ｓと
比較してＳ２＋イオンの供給がゆっくり進行するＳＣ
（ＮＨ２）２を用いることにより、薄膜が基材上に効率
よく析出するものと考えられる。Further, the above reagents and their concentration conditions are as follows:
Since the concentration of Zn 2+ freely present in the solution is reduced by using the complexing agent, and the concentration of OH − is reduced by using the buffering agent, the ion concentration product falls below the solubility product, Furthermore, SC in which the supply of S 2+ ions proceeds more slowly than sodium sulfide Na 2 S
It is considered that the thin film is efficiently deposited on the substrate by using (NH 2 ) 2 .

【００６４】一方、基材にはソーダ石灰ガラス製のスラ
イドガラスを１ｍｏｌ／ｌの水酸化ナトリウムＮａＯＨ
水溶液に１２時間浸したものを使用した。５種類の試薬
を所定の濃度になるように１００ｍｌの水に加え、この
溶液中に基材を浸し、攪拌しながら最初８５℃で１０分
間加熱し、その後室温で６時間析出させた。溶液の加熱
は反応の促進と基材の活性化を目的としている。さらに
基材を水洗した後２００℃で２時間アニールを行った。On the other hand, as the base material, a glass slide made of soda-lime glass was used, and 1 mol / l of sodium hydroxide NaOH was used.
What was soaked in the aqueous solution for 12 hours was used. Five kinds of reagents were added to 100 ml of water so as to have a predetermined concentration, and the substrate was immersed in this solution, heated at 85 ° C. for 10 minutes with stirring, and then precipitated at room temperature for 6 hours. The heating of the solution is intended to accelerate the reaction and activate the substrate. Further, the base material was washed with water and then annealed at 200 ° C. for 2 hours.

【００６５】以上の手順に従った実験によって得られた
基材上には非常に透明度の高い薄膜が析出していること
が観察された。そこでこの薄膜試料に対し、ＸＲＤ（Ｘ
線回折）を用いて結晶相の同定を試みたが、回折ピーク
を生じるほど結晶性の良い薄膜の生成は確認できなかっ
た。そこで次に、ＥＤＸ（エネルギー分散Ｘ線分析）に
よって、この薄膜の元素分析を行ったところＺｎとＳと
が存在していることが確認され、この結果よりＺｎＳ薄
膜が析出したことを確認した。It was observed that a highly transparent thin film was deposited on the substrate obtained by the experiment according to the above procedure. Therefore, for this thin film sample, XRD (X
Attempts were made to identify the crystal phase using line diffraction), but it was not possible to confirm the formation of a thin film having good crystallinity enough to generate a diffraction peak. Then, next, elemental analysis of this thin film was performed by EDX (energy dispersive X-ray analysis), and it was confirmed that Zn and S were present, and it was confirmed from this result that the ZnS thin film was deposited.

【００６６】緩衝剤である硫酸アンモニウム（（Ｎ
Ｈ４）２ＳＯ４）は、反応浴槽の温度上昇によって増加
したｐＨを下げることができる、即ち、浴槽のｐＨが上
昇するとＯＨ−が増加し、Ｚｎ（ＯＨ）２が浴槽中に析
出してしまうのを阻止することができるものと考えられ
る。ここで、ＺｎＳ薄膜はＮＨ３およびＮ２Ｈ４のどち
らか一方だけでは作製できず、両方を同時に用いること
によってのみ作製可能であることが確認された。Ammonium sulfate ((N
H 4 ) 2 SO 4 ) can lower the pH increased by increasing the temperature of the reaction bath, that is, when the pH of the bath increases, OH − increases and Zn (OH) 2 precipitates in the bath. It is thought that it is possible to prevent it. Here, it was confirmed that the ZnS thin film cannot be formed by only one of NH 3 and N 2 H 4 , and can be formed only by using both of them simultaneously.

【００６７】また、薄膜析出における温度依存性につい
ては、室温プロセスのみでは薄膜は析出しないと判断さ
れる。高温においては溶液自体が白色に変色したため、
溶液中に粒子が析出したものと考えられる。そのため、
薄膜析出条件における温度依存性は重要であると考えら
れる。Regarding the temperature dependence of thin film deposition, it is judged that the thin film does not deposit only by the room temperature process. At high temperature, the solution itself turned white,
It is considered that particles were precipitated in the solution. for that reason,
It is considered that the temperature dependence in the thin film deposition conditions is important.

【００６８】次に、ＺｎＯ薄膜の作製について説明す
る。上記ＺｎＳ薄膜作製の時に用いたＳＣ（ＮＨ２）２
の代わりに、尿素ＣＯ（ＮＨ２）２を用いてＺｎＯ薄膜
の作製を試みた。そこにおいて前記５種類の試薬、即ち
Ｚｎの前駆物質として硫酸亜鉛７水和物（ＺｎＳＯ４・
７Ｈ２Ｏ）、Ｓの前駆物質としてチオ尿素（ＳＣ（ＮＨ
２）２）、アンモニア水溶液（ＮＨ３）、およびヒドラ
ジン１水和物（Ｎ２Ｈ４・Ｈ２Ｏ）、硫酸アンモニウム
（（ＮＨ４） ２ＳＯ４）を選択的に用いてＺｎＯ薄膜の
作製を試みた。Next, the production of the ZnO thin film will be described.
It SC (NHTwo)Two
Instead of urea CO (NHTwo)TwoZnO thin film using
I tried to make. There, the five reagents,
Zinc sulfate heptahydrate as a precursor of Zn (ZnSOFour・
7HTwoO) and thiourea (SC (NH
Two)Two), Aqueous ammonia solution (NHThree), And hydra
Gin monohydrate (NTwoHFour・ HTwoO), ammonium sulfate
((NHFour) TwoSOFour) Of ZnO thin film
Tried to make.

【００６９】ＺｎＯ薄膜は上記したようにＺｎＳ薄膜生
成機構の途中の段階、あるいは、試薬の有無による条件
の変化により生成した。これは、Ｚｎ２＋のＮＨ３また
はＮ ２Ｈ４による錯体化とＯＨ−との反応による生成で
あると考えられる。反応機構は次の通りである。The ZnO thin film is a ZnS thin film as described above.
Conditions in the middle of the mechanism or depending on the presence or absence of reagents
Generated by the change of. This is Zn2+NHThreeAlso
Is N TwoHFourComplexation with OH−By the reaction with
It is believed that there is. The reaction mechanism is as follows.

【００７０】[0070]

【化１１】Ｚｎ２＋＋４（ＮＨ３）←→［Ｚｎ（Ｎ
Ｈ３）４］２＋ Ｚｎ２＋＋３Ｎ２Ｈ４←→［Ｚｎ（ＮＨ４）３］２＋ ＮＨ３＋Ｈ２Ｏ←→ＮＨ４ ＋＋ＯＨ− Ｎ２Ｈ４＋Ｈ２Ｏ←→Ｎ２Ｈ５ ＋＋ＯＨ− ［Ｚｎ（ＮＨ３）４］２＋＋ＯＨ−←→Ｚｎ（ＯＨ）２
＋ＮＨ３ ［Ｚｎ（Ｎ２Ｈ４）３］２＋＋ＯＨ−←→Ｚｎ（ＯＨ）
２＋Ｎ２Ｈ４ Embedded image Zn 2+ +4 (NH 3 ) ← → [Zn (N
H 3) 4] 2+ Zn 2+ + 3N 2 H 4 ← → [Zn (NH 4) 3] 2+ NH 3 + H 2 O ← → NH 4 + + OH - N 2 H 4 + H 2 O ← → N 2 H 5 + + OH - [Zn (NH 3) 4 ] 2+ + OH - ← → Zn (OH) 2
+ NH 3 [Zn (N 2 H 4 ) 3 ] 2+ + OH − ← → Zn (OH)
2 + N 2 H 4

【００７１】以上の反応プロセスによって最初にＺｎ
（ＯＨ）２が析出し、アニールによって酸化物に変化す
るものと考えられる。以下の表１に反応溶液の組成が異
なる場合における薄膜析出状態をまとめて示す。単位は
ｍｏｌ／ｌである。By the above reaction process, first Zn
It is considered that (OH) 2 is deposited and converted into an oxide by annealing. Table 1 below collectively shows the thin film deposition state when the composition of the reaction solution is different. The unit is mol / l.

【００７２】[0072]

【表１】 [Table 1]

【００７３】表１に示された実施例１〜５から、反応溶
液の選択によってＺｎＳおよびＺｎＯ薄膜作製がなされ
ることが確認できる。いずれの場合もＺｎ前駆物質とＳ
Ｃ（ＮＨ２）２だけではＺｎＳは溶液中にも基材上にも
析出しないことが確認され、これにより錯化剤の添加が
必要不可欠であることが明らかとなった。From Examples 1 to 5 shown in Table 1, it can be confirmed that ZnS and ZnO thin films are prepared by selecting the reaction solution. In both cases, Zn precursor and S
It was confirmed that ZnS did not precipitate in the solution or on the base material only with C (NH 2 ) 2 , and it became clear that the addition of the complexing agent was essential.

【００７４】また、Ｎ２Ｈ４のみの添加条件ではそのＺ
ｎ２＋との錯体の安定度定数が低いためと思われる沈殿
物が確認された。このため２種類の錯化剤を同時に使用
することが好ましい。Further, under the adding condition of N 2 H 4 alone, the Z
Precipitates were observed, which may be due to the low stability constant of the complex with n 2+ . Therefore, it is preferable to use two kinds of complexing agents at the same time.

【００７５】作製された薄膜の構造解析および形態評価
は、ＸＲＤ（Ｘ線回折）、ＳＥＭ（走査型電子顕微
鏡）、ＴＥＭ（透過型電子顕微鏡）およびＥＤＸ（エネ
ルギー分散Ｘ線分析）によって行った。その結果、Ｚｎ
Ｓ薄膜では非常に小さい粒子が均質に配列されており、
ＺｎＯ薄膜では結晶系や成長方向、結晶の形状がそれぞ
れ異なる六方晶の単結晶が観察された（詳細は省略）。Structural analysis and morphological evaluation of the produced thin film were carried out by XRD (X-ray diffraction), SEM (scanning electron microscope), TEM (transmission electron microscope) and EDX (energy dispersive X-ray analysis). As a result, Zn
In the S thin film, very small particles are arranged uniformly,
In the ZnO thin film, hexagonal single crystals having different crystal systems, growth directions, and crystal shapes were observed (details omitted).

【００７６】実施例６〜１０ 実施例６〜１０としてＣｄＳ薄膜による光触媒の作製方
法を説明する。ＣｄＳの溶解度積は５．０１×１０
−２８［（ｍｏｌ／ｌ）２］と非常に小さく、溶液中の
Ｃｄ２＋濃度をコントロールすることが薄膜制御の重要
な因子である。そこで溶液中のＣｄ２＋濃度を飽和以下
にするために、錯化剤としてアンモニアＮＨ ３を用い
た。Ｃｄ２＋イオン発生種として３ＣｄＳＯ４・８Ｈ２
Ｏを、Ｓ２−イオン発生種としてチオ尿素ＳＣ（Ｎ
Ｈ２）２を用いた。ＮＨ３は水中でアンモニウムイオン
ＮＨ４ ＋と水酸化物イオンＯＨ−に解離し、ＯＨ−はＳ
Ｃ（ＮＨ２） ２を分解してＳ２−を放出する。そして、
最終的には化学式Examples 6-10 As Examples 6 to 10, a method for producing a photocatalyst using a CdS thin film
Explain the method. The solubility product of CdS is 5.01 × 10
-28[(Mol / l)Two] And very small in solution
Cd2+Controlling concentration is important for thin film control
Is a factor. So Cd in the solution2+Below saturation
Ammonia ammonia as a complexing agent ThreeUsing
It was Cd2+3CdSO as ion generating speciesFour・ 8HTwo
O for S2-Thiourea SC (N
HTwo)TwoWas used. NHThreeIs ammonium ion in water
NHFour +And hydroxide ion OH−Dissociates into OH−Is S
C (NHTwo) TwoDisassemble S2-To release. And
Eventually the chemical formula

【００７７】[0077]

【化１２】Ｃｄ２＋＋Ｓ２−→ＣｄＳ[Chemical Formula 12] Cd 2+ + S 2- → CdS

【００７８】で表される反応によって析出する。そこ
で、ＮＨ３濃度、および加熱速度をパラメータとしてい
くつかの条件下でＣｄＳ薄膜を作製し、評価した。Precipitation occurs by the reaction represented by: Therefore, a CdS thin film was prepared and evaluated under some conditions with the NH 3 concentration and the heating rate as parameters.

【００７９】ＣｄＳ薄膜の形成においては、ＮＨ３濃度
の変化によって膜厚が制御可能である。即ち、１００ｍ
ｌメスフラスコを用いて３ＣｄＳＯ４・８Ｈ２Ｏを０．
０１ｍｏｌ／ｌ、チオ尿素ＳＣ（ＮＨ２）２を０．０１
ｍｏｌ／ｌおよび２５ｗｔ．％のＮＨ３を１．０ｍｏｌ
／ｌ［実施例６］、１．２ｍｏｌ／ｌ［実施例７］、
１．５ｍｏｌ／ｌ［実施例８］、１．８ｍｏｌ／ｌ［実
施例９］、２．０ｍｏｌ／ｌ［実施例１０］となるよう
に秤量し、溶液を調整した。即ち、各々の実施例６〜１
０においてはＮＨ３の濃度が異なる。In the formation of the CdS thin film, the film thickness can be controlled by changing the NH 3 concentration. That is, 100m
3 CdSO 4 .8H 2 O was added to 0.2
01 mol / l, thiourea SC (NH 2 ) 2 0.01
mol / l and 25 wt. % NH 3 1.0 mol
/ L [Example 6], 1.2 mol / l [Example 7],
The solution was adjusted to weigh 1.5 mol / l [Example 8], 1.8 mol / l [Example 9], and 2.0 mol / l [Example 10]. That is, each of Examples 6 to 1
At 0, the NH 3 concentration is different.

【００８０】この方法によって得られた薄膜は薄橙色を
しており、これはカドミウムイエローと呼ばれるＣｄＳ
に特有の色であり、ＣｄＳの存在を示唆するものであ
る。そこでＸＲＤにより相の同定を行った結果、実施例
６〜８ではＣｄＳ、ＣｄＯおよびＣｄ（ＯＨ）２が、実
施例９ではＣｄＳが確認され、実施例１０ではごく僅か
のＣｄＳが確認された。このように、濃度の濃い方が薄
い膜厚が得られることが分かった。また得られた薄膜
は、ＮＨ３の濃度によってその色と透明度に相違が見ら
れた。The thin film obtained by this method has a light orange color, which is CdS called Cadmium Yellow.
Is a color peculiar to CdS and suggests the presence of CdS. Therefore, as a result of phase identification by XRD, CdS, CdO and Cd (OH) 2 were confirmed in Examples 6 to 8, CdS was confirmed in Example 9, and only a slight amount of CdS was confirmed in Example 10. Thus, it was found that the higher the concentration, the thinner the film thickness obtained. Further, the obtained thin film showed a difference in its color and transparency depending on the concentration of NH 3 .

【００８１】また、ＣＢＤ法においては、加熱すること
によって、ＣｄＳの析出粒子を変化させることができ
る。即ち、温度上昇に応じて基材上に核生成反応が起こ
り、その核を中心に結晶が成長する。しかし、急激な温
度変化は結晶の成長を待たずにより多くの核の生成を促
す。Further, in the CBD method, the precipitated particles of CdS can be changed by heating. That is, a nucleation reaction occurs on the base material as the temperature rises, and crystals grow around the nuclei. However, the rapid temperature change promotes the generation of more nuclei without waiting for the crystal growth.

【００８２】また、析出量は加熱速度が遅いほど多い。
ＮＨ３とＣｄ２＋の平衡が移動し、膜の生成が起こり始
める温度は観察から５０〜６０℃であり、この温度範囲
に保持された時間が長いほど結晶の成長が進み、析出量
が増大するためと考えられる。このように、ＮＨ３濃度
および加熱速度条件の違いによりＣｄＳ薄膜の膜厚およ
び粒径を制御することができる。The amount of precipitation increases as the heating rate decreases.
From the observation, the temperature at which the equilibrium of NH 3 and Cd 2+ shifts and film formation starts is 50 to 60 ° C., and the longer the temperature is kept in this temperature range, the more the crystal growth proceeds and the precipitation amount increases. It is thought to be because. Thus, the film thickness and grain size of the CdS thin film can be controlled by the difference in NH 3 concentration and heating rate conditions.

【００８３】実施例１１ 上記した方法で形成したＺｎＳ薄膜について、その断面
の元素分布を透過型電子顕微鏡（ＴＥＭ）およびエネル
ギー分散Ｘ線分析（ＥＤＸ）によって解析した。薄膜の
作製は、６時間の析出を３回行った後アニールすること
により形成した。なお、薄膜試料の最表面はタングステ
ンでコーティングした。図８は得られたＺｎＳ薄膜の断
面形状を示すＴＥＭ写真であり、図９は図８におけるＺ
ｎの原子分布を示すＴＥＭ−ＥＤＭ写真であり、図１０
は図８におけるＳの原子分布を示すＴＥＭ−ＥＤＭ写真
であり、図１１は図８におけるＯの原子分布を示すＴＥ
Ｍ−ＥＤＭ写真である。図１１から、このＺｎＳ薄膜に
は、酸素原子が含有されていることが分かる。Example 11 With respect to the ZnS thin film formed by the above method, the element distribution in the cross section was analyzed by a transmission electron microscope (TEM) and energy dispersive X-ray analysis (EDX). The thin film was formed by performing deposition for 6 hours three times and then annealing. The outermost surface of the thin film sample was coated with tungsten. FIG. 8 is a TEM photograph showing a cross-sectional shape of the obtained ZnS thin film, and FIG. 9 shows Z in FIG.
11 is a TEM-EDM photograph showing the atomic distribution of n, and FIG.
8 is a TEM-EDM photograph showing the atomic distribution of S in FIG. 8, and FIG. 11 is TE showing the atomic distribution of O in FIG.
It is an M-EDM photograph. From FIG. 11, it can be seen that this ZnS thin film contains oxygen atoms.

【００８４】実施例１２ 上記した方法で形成したＺｎＳ−ＣｄＳ薄膜について、
その断面の元素分布を透過型電子顕微鏡（ＴＥＭ）およ
びエネルギー分散Ｘ線分析（ＥＤＸ）によって解析し
た。薄膜の作製は、６時間の析出を３回行った後アニー
ルして得られたＺｎＳ薄膜の上に、さらにＣｄＳ薄膜を
２〜３時間の析出を３回行った後アニールして形成し
た。なお、薄膜試料の最表面はタングステンでコーティ
ングした。図１２は得られたＺｎＳ−ＣｄＳ薄膜の断面
形状を示すＴＥＭ写真であり、図１３は図１２における
Ｚｎの原子分布を示すＴＥＭ−ＥＤＭ写真であり、図１
４は図１２におけるＣｄの原子分布を示すＴＥＭ−ＥＤ
Ｍ写真であり、図１５は図１２におけるＳの原子分布を
示すＴＥＭ−ＥＤＭ写真であり、図１６は図１２におけ
るＯの原子分布を示すＴＥＭ−ＥＤＭ写真である。図１
６から、このＺｎＳ−ＣｄＳ薄膜にも酸素原子が含有さ
れていることが分かる。Example 12 With respect to the ZnS-CdS thin film formed by the above method,
The element distribution of the cross section was analyzed by a transmission electron microscope (TEM) and energy dispersive X-ray analysis (EDX). The thin film was formed by depositing a CdS thin film on the ZnS thin film obtained by annealing for 6 hours three times and then annealing, and further annealing for 3 to 3 hours and then annealing. The outermost surface of the thin film sample was coated with tungsten. 12 is a TEM photograph showing the cross-sectional shape of the obtained ZnS-CdS thin film, and FIG. 13 is a TEM-EDM photograph showing the atomic distribution of Zn in FIG.
4 is a TEM-ED showing the atomic distribution of Cd in FIG.
15 is a TEM-EDM photograph showing the atomic distribution of S in FIG. 12, and FIG. 16 is a TEM-EDM photograph showing the atomic distribution of O in FIG. Figure 1
It can be seen from 6 that this ZnS-CdS thin film also contains oxygen atoms.

【００８５】（薄膜状光触媒による水素発生） （１） 実施例１〜５の薄膜状光触媒について 次に、上記試料について光触媒としての活性を調べるた
め、図１７に示すような装置を用いて、光触媒による水
素発生の実験を行った。この装置は、図１７に示すよう
に、石英ガラス製の光反応容器１１と、発生した水素ガ
スの定量を行う水素定量部分１３と、水素ガス発生によ
って装置内の圧力が上昇することを防ぐための溶液溜１
５と、光線照射用の５００Ｗ水銀灯（図示省略）と、光
線１７を集光するための集光レンズ１９と、光線１７を
光触媒に照射するための反射鏡２１とで構成されてい
る。操作は、初めに系全体を硫化ナトリウム水溶液で満
たし、薄膜状光触媒を光反応容器１１の底に沈殿させ、
ガス抜き栓２３を閉じた後、５００Ｗ水銀灯を容器１１
の底部から点灯し、水素定量部分１３で一定照射時間ご
とに水素発生量を測定するものである。(Hydrogen Generation by Thin Film Photocatalyst) (1) Regarding Thin Film Photocatalysts of Examples 1-5 Next, in order to examine the activity of the above samples as a photocatalyst, a photocatalyst was used using an apparatus as shown in FIG. Experiment of hydrogen generation was conducted. As shown in FIG. 17, this device has a photoreaction vessel 11 made of quartz glass, a hydrogen quantitative portion 13 for quantitatively determining the generated hydrogen gas, and a hydrogen gas generation prevent the pressure in the device from rising. Solution reservoir 1
5, a 500 W mercury lamp (not shown) for irradiating a light beam, a condenser lens 19 for condensing the light beam 17, and a reflecting mirror 21 for irradiating the light catalyst 17 with the photocatalyst. In operation, first, the entire system is filled with an aqueous sodium sulfide solution, and the thin film photocatalyst is precipitated on the bottom of the photoreaction vessel 11,
After closing the gas vent plug 23, put a 500 W mercury lamp on the container 11.
Is lit from the bottom, and the amount of hydrogen generated is measured in the hydrogen quantitative portion 13 at constant irradiation times.

【００８６】ここで反射鏡２１は可視〜紫外光用（シグ
マ光機ＴＦＡＨ１００−１５−０．３）を、５００Ｗ水
銀灯はワコム電創ＢＮＭＯ−５００ＤＩの超高圧水銀ラ
ンプを、集光レンズは石英製のものを使用した。Here, the reflecting mirror 21 is for visible to ultraviolet light (Sigma optical device TFAH100-15-0.3), the 500 W mercury lamp is a Wacom Denso BNMO-500DI ultra-high pressure mercury lamp, and the condenser lens is made of quartz. I used the one.

【００８７】上記の薄膜状光触媒による水溶液からの水
素発生実験は、ＣＢＤ法により３０ｍｍ×２２ｍｍのガ
ラス基材上に作製した薄膜に０．１ＭのＮａ２Ｓ水溶液
１４０ｍｌ中で光照射したときの水素発生量を測定し
た。試料としては表１に示した実施例１（ＺｎＳ薄
膜）、実施例２，４，５（ＺｎＯ薄膜）、および粒子状
のＺｎＯ（参考例）を用いた。The hydrogen generation experiment from the aqueous solution using the above thin film photocatalyst was carried out by the CBD method when a thin film prepared on a glass substrate of 30 mm × 22 mm was irradiated with light in 140 ml of 0.1 M Na 2 S aqueous solution. The amount generated was measured. As a sample, Example 1 (ZnS thin film), Examples 2, 4, and 5 (ZnO thin film) shown in Table 1, and particulate ZnO (reference example) were used.

【００８８】実験結果は図１に示すように、横軸に照射
時間を３００分までとり、その時の水素発生量を縦軸に
７０ｍｌまでとった。図１から分かるように、水素発生
量はほぼ照射時間に比例している。３００分までの範囲
ではほぼ直線上に乗り、各試料の劣化はそれほど著しい
ものではないことが分かる。As shown in FIG. 1, the experimental results were such that the horizontal axis indicates the irradiation time up to 300 minutes and the vertical axis indicates the hydrogen generation amount up to 70 ml. As can be seen from FIG. 1, the hydrogen generation amount is almost proportional to the irradiation time. It can be seen that in the range of up to 300 minutes, the samples are on a substantially straight line, and the deterioration of each sample is not so remarkable.

【００８９】ここで微粒子のＺｎＯ試料の使用量は５０
〜１００ｍｇである。それに対して薄膜状の各試料は１
ｍｇにも満たない。それにもかかわらず、薄膜状の試料
からは、５０〜１００ｍｇの微粒子の５０〜６０％に相
当する量の水素が発生した。これは、粒子状よりも、薄
膜状にして基材上に固定して用いる方法が、はるかに光
反応効率が高いことを示している。Here, the amount of the fine ZnO sample used is 50.
~ 100 mg. On the other hand, each thin film sample is 1
It is less than mg. Nevertheless, the thin film-like sample generated hydrogen in an amount corresponding to 50 to 60% of 50 to 100 mg of fine particles. This indicates that the method of forming a thin film and immobilizing it on the base material has a much higher photoreaction efficiency than the particulate form.

【００９０】このように薄膜状にすると高効率になる理
由は、光触媒を薄膜状で固定化して使用することによ
り、薄膜表面に適当な凹凸が存在して大きな表面積を持
つこと、そして微細な触媒粒子が基材上に固定化されて
いるために照射光を受けてそのエネルギーを水素発生に
変換する効率が改善されたためと考えられる。The reason why such a thin film has a high efficiency is that the photocatalyst is used by fixing it in a thin film form so that the surface of the thin film has appropriate irregularities and has a large surface area, and a fine catalyst. It is considered that the particles are immobilized on the base material, so that the efficiency of receiving the irradiation light and converting the energy into hydrogen generation is improved.

【００９１】薄膜間で比較すると、ＺｎＳ薄膜の単位時
間当たりの水素発生量はＺｎＯのそれよりもわずかに低
いといえる。その原因の一つは薄膜の表面積の違いによ
るものと考えられる。Comparing the thin films, it can be said that the hydrogen generation amount per unit time of the ZnS thin film is slightly lower than that of ZnO. One of the causes is considered to be due to the difference in the surface area of the thin film.

【００９２】また、異なる条件下で作製したＺｎＯ薄膜
の間でも違いが見られた。その中でも実施例４、即ちＺ
ｎＳＯ４、ＮＨ３、Ｎ２Ｈ４で作製した薄膜が、最も高
い水素発生量を得た。この原因はその結晶構造にあると
考えられる。但し、いずれの場合も水素発生量の違いが
非常に微少であるため、現段階ではどの薄膜が最も水素
を発生させるのかを判断するのは難しい。Differences were also observed between ZnO thin films prepared under different conditions. Among them, Example 4, namely Z
The thin film made of nSO 4 , NH 3 , and N 2 H 4 obtained the highest hydrogen generation amount. It is considered that this is due to its crystal structure. However, in both cases, the difference in the amount of hydrogen generated is very small, so it is difficult to judge which thin film generates the most hydrogen at this stage.

【００９３】（２）実施例６〜１０の薄膜状光触媒につ
いて 次に、実施例６〜１０、即ちＣｄＳ薄膜の実施例につい
ての水素発生量について説明する。既に述べたようにＮ
Ｈ３濃度および加熱速度条件の違いによってＣｄＳ薄膜
の膜厚および粒径を制御することができる。種々のＮＨ
３濃度条件で作製したＣｄＳ薄膜実施例６〜１０を用い
て０．１ｍｏｌ／ｌに調整したＮａ２Ｓ溶液中で光照射
実験を行い、図２の結果を得た。図２から分かるよう
に、一般的にはＮＨ３濃度の薄い方が膜厚は厚いことは
既に述べたとおりであり、ＣｄＳ薄膜の厚いものの方が
より水素発生量が多いことが分かる。(2) Thin Film Photocatalysts of Examples 6 to 10 Next, the hydrogen generation amount of Examples 6 to 10, that is, the example of the CdS thin film will be described. As I said, N
The thickness and grain size of the CdS thin film can be controlled by the difference in H 3 concentration and heating rate conditions. Various NH
A light irradiation experiment was conducted in a Na 2 S solution adjusted to 0.1 mol / l using the CdS thin film Examples 6 to 10 produced under 3 concentration conditions, and the results of FIG. 2 were obtained. As can be seen from FIG. 2, generally, the thinner the NH 3 concentration is, the thicker the film thickness is, and it can be seen that the thicker the CdS thin film is, the larger the hydrogen generation amount is.

【００９４】これは厚い膜ほど吸光度が大きく、照射さ
れた光をより多く吸収することができたからであると考
えられる。しかし、ＮＨ３濃度が１．５ｍｏｌ／ｌ以下
の膜は、光の吸収という観点から見るとほとんどの光を
吸収していて粒径に関してもほとんど差異は認められな
いにも関わらず、水素発生量については大きな差異が現
れた。It is considered that this is because the thicker the film, the higher the absorbance and the more the irradiated light could be absorbed. However, from the viewpoint of light absorption, a film with an NH 3 concentration of 1.5 mol / l or less absorbs most of the light, and although there is almost no difference in the particle size, the amount of hydrogen generated is There was a big difference.

【００９５】[0095]

【発明の効果】上述したように、本発明によれば、廉価
で取り扱いに便利な高活性の薄膜状光触媒を提供でき
る。またこの薄膜状光触媒は、環境有害物質である硫化
水素を簡単な工程で、亜硫酸ガスのような有害物質を発
生することなく処理して、工業全般に有用な硫黄と水素
を効率よく安価に製造することができる。さらに、この
高活性光触媒を用いた硫化水素の処理方法を原油などの
脱硫工程や、水素の製造方法に適用すれば、硫化水素の
処理によって生じた水素を再度脱硫工程に使用すること
ができ、極めて有用なケミカル・リサイクルが可能とな
る。As described above, according to the present invention, a highly active thin film photocatalyst which is inexpensive and convenient to handle can be provided. In addition, this thin film photocatalyst processes hydrogen sulfide, which is an environmentally harmful substance, in a simple process without producing harmful substances such as sulfurous acid gas, and efficiently and inexpensively produces sulfur and hydrogen, which are useful for all industries. can do. Furthermore, if a method for treating hydrogen sulfide using this highly active photocatalyst is applied to a desulfurization step such as crude oil, or a method for producing hydrogen, hydrogen generated by the treatment of hydrogen sulfide can be used again in the desulfurization step, Enables extremely useful chemical recycling.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明によるＺｎ化合物の薄膜状光触媒を用い
た時の光照射時間と水素発生量との関係を示すグラフで
ある。FIG. 1 is a graph showing a relationship between a light irradiation time and a hydrogen generation amount when a thin film photocatalyst of a Zn compound according to the present invention is used.

【図２】本発明によるＣｄ化合物の薄膜状光触媒を用い
た時の光照射時間と水素発生量との関係を示すグラフで
ある。FIG. 2 is a graph showing the relationship between the light irradiation time and the hydrogen generation amount when the thin film photocatalyst of the Cd compound according to the present invention is used.

【図３】一般的な原油の脱硫工程を概略的に示す図であ
る。FIG. 3 is a diagram schematically showing a general crude oil desulfurization process.

【図４】硫化水素の処理方法の従来技術（クラウス法）
を例示する図である。FIG. 4 Conventional technology for treating hydrogen sulfide (Klaus method)
It is a figure which illustrates.

【図５】水素製造方法の従来技術（深冷水素精製法もし
くは窒素洗浄法）を例示する図である。FIG. 5 is a diagram exemplifying a conventional technique of a hydrogen production method (deep cold hydrogen purification method or nitrogen cleaning method).

【図６】ＣＢＤ法による薄膜状光触媒の作製装置を示す
模式的斜視図である。FIG. 6 is a schematic perspective view showing an apparatus for producing a thin film photocatalyst by the CBD method.

【図７】本発明の一実施の形態にかかる硫化水素の処理
システムを概略的に示す図である。FIG. 7 is a diagram schematically showing a hydrogen sulfide treatment system according to an embodiment of the present invention.

【図８】ＺｎＳ薄膜の断面形状を示すＴＥＭ写真であ
る。FIG. 8 is a TEM photograph showing a cross-sectional shape of a ZnS thin film.

【図９】図８におけるＺｎの原子分布を示すＴＥＭ−Ｅ
ＤＭ写真である。9 is a TEM-E showing the atomic distribution of Zn in FIG.
It is a DM photograph.

【図１０】図８におけるＳの原子分布を示すＴＥＭ−Ｅ
ＤＭ写真である。10 is a TEM-E showing the atomic distribution of S in FIG.
It is a DM photograph.

【図１１】図８におけるＯの原子分布を示すＴＥＭ−Ｅ
ＤＭ写真である。11 is a TEM-E showing the atomic distribution of O in FIG.
It is a DM photograph.

【図１２】ＺｎＳ−ＣｄＳ薄膜の断面形状を示すＴＥＭ
写真である。FIG. 12 is a TEM showing a cross-sectional shape of a ZnS-CdS thin film.
It is a photograph.

【図１３】図１２におけるＺｎの原子分布を示すＴＥＭ
−ＥＤＭ写真である。FIG. 13 is a TEM showing the atomic distribution of Zn in FIG.
-EDM photograph.

【図１４】図１２におけるＣｄの原子分布を示すＴＥＭ
−ＥＤＭ写真である。FIG. 14 is a TEM showing the atomic distribution of Cd in FIG.
-EDM photograph.

【図１５】図１２におけるＳの原子分布を示すＴＥＭ−
ＥＤＭ写真である。15 is a TEM- showing the atomic distribution of S in FIG.
It is an EDM photograph.

【図１６】図１２におけるＯの原子分布を示すＴＥＭ−
ＥＤＭ写真である。16 is a TEM- showing the atomic distribution of O in FIG.
It is an EDM photograph.

【図１７】本発明にかかる化合物半導体の薄膜状光触媒
の活性を調べるための実験装置を示す図である。FIG. 17 is a view showing an experimental apparatus for investigating the activity of the thin film photocatalyst of the compound semiconductor according to the present invention.

【符号の説明】[Explanation of symbols]

１……硫化水素溶解槽、３……光触媒反応槽、５……硫
黄回収槽、７……光源、１１……光反応容器、１３……
水素定量部分、１５……溶液溜、１７……光線、１９…
…集光レンズ、２１……反射鏡、２３……ガス抜き栓、
６１……熱撹拌機、６２……反応溶液、６３……基材、
６４……磁気攪拌子、６５……基材をつるす糸。1 ... Hydrogen sulfide dissolution tank, 3 ... Photocatalytic reaction tank, 5 ... Sulfur recovery tank, 7 ... Light source, 11 ... Photoreaction container, 13 ...
Hydrogen quantitative portion, 15 ... solution reservoir, 17 ... light beam, 19 ...
… Condenser lens, 21 …… Reflector, 23 …… Gas vent plug,
61 ... Thermal stirrer, 62 ... Reaction solution, 63 ... Base material,
64: Magnetic stirrer, 65: Thread for suspending the base material.

───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｃ０１Ｂ 3/04 Ｃ０１Ｂ 3/04 Ｚ 17/05 17/05 Ｚ Ｆターム(参考） 4G069 AA03 AA08 BB04A BB04B BB09A BB09B BC35A BC35B BC36A BC36B CD10 DA06 EA08 FA01 FA03 4G075 AA24 BA10 BB10 CA51 DA02─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) C01B 3/04 C01B 3/04 Z 17/05 17/05 Z F term (reference) 4G069 AA03 AA08 BB04A BB04B BB09A BB09B BC35A BC35B BC36A BC36B CD10 DA06 EA08 FA01 FA03 4G075 AA24 BA10 BB10 CA51 DA02

Claims (12)

【特許請求の範囲】[Claims] 【請求項１】 基材上に化合物半導体よりなる層が固定
化され、該化合物半導体は酸素原子を含むことを特徴と
する薄膜状光触媒。1. A thin-film photocatalyst in which a layer made of a compound semiconductor is immobilized on a substrate, and the compound semiconductor contains an oxygen atom. 【請求項２】 前記化合物半導体が金属硫化物であるこ
とを特徴とする請求項１記載の薄膜状光触媒。2. The thin-film photocatalyst according to claim 1, wherein the compound semiconductor is a metal sulfide. 【請求項３】 前記化合物半導体が硫化亜鉛または硫化
カドミウムであることを特徴とする請求項２記載の薄膜
状光触媒。3. The thin-film photocatalyst according to claim 2, wherein the compound semiconductor is zinc sulfide or cadmium sulfide. 【請求項４】 化合物半導体原料となる化学種を含む溶
液中に基材を浸漬し、化学浴槽析出法（ＣＢＤ法）によ
り前記基材表面に化合物半導体を析出・固定化させてな
ることを特徴とする薄膜状光触媒の作製方法。4. A compound semiconductor is prepared by immersing a base material in a solution containing a chemical species as a compound semiconductor raw material, and depositing and fixing the compound semiconductor on the surface of the base material by a chemical bath deposition method (CBD method). A method for producing a thin film photocatalyst. 【請求項５】 前記化合物半導体が金属硫化物であるこ
とを特徴とする請求項４記載の薄膜状光触媒の作製方
法。5. The method for producing a thin film photocatalyst according to claim 4, wherein the compound semiconductor is a metal sulfide. 【請求項６】 前記化合物半導体が硫化亜鉛または硫化
カドミウムであることを特徴とする請求項５記載の薄膜
状光触媒の作製方法。6. The method for producing a thin film photocatalyst according to claim 5, wherein the compound semiconductor is zinc sulfide or cadmium sulfide. 【請求項７】 基材上に化合物半導体よりなる層が固定
化された薄膜状光触媒を、硫化水素を溶解させた溶液中
に浸漬して、水素と硫黄を回収することを特徴とする薄
膜状光触媒を用いた硫化水素の処理方法。7. A thin film-shaped photocatalyst in which a layer made of a compound semiconductor is fixed on a base material, is immersed in a solution in which hydrogen sulfide is dissolved, and hydrogen and sulfur are recovered. A method for treating hydrogen sulfide using a photocatalyst. 【請求項８】 前記化合物半導体が金属硫化物であるこ
とを特徴とする請求項７記載の硫化水素の処理方法。8. The method for treating hydrogen sulfide according to claim 7, wherein the compound semiconductor is a metal sulfide. 【請求項９】 前記化合物半導体が硫化亜鉛または硫化
カドミウムであることを特徴とする請求項８記載の硫化
水素の処理方法。9. The method for treating hydrogen sulfide according to claim 8, wherein the compound semiconductor is zinc sulfide or cadmium sulfide. 【請求項１０】 基材上に化合物半導体よりなる層が固
定化された薄膜状光触媒を、硫化水素を溶解させた溶液
中に浸漬して、水素を製造することを特徴とする薄膜状
光触媒を用いた水素の製造方法。10. A thin-film photocatalyst in which a thin film photocatalyst in which a layer made of a compound semiconductor is immobilized on a substrate is immersed in a solution in which hydrogen sulfide is dissolved to produce hydrogen. Used hydrogen production method. 【請求項１１】 前記化合物半導体が金属硫化物である
ことを特徴とする請求項１０記載の水素の製造方法。11. The method for producing hydrogen according to claim 10, wherein the compound semiconductor is a metal sulfide. 【請求項１２】 前記化合物半導体が硫化亜鉛または硫
化カドミウムであることを特徴とする請求項１１記載の
水素の製造方法。12. The method for producing hydrogen according to claim 11, wherein the compound semiconductor is zinc sulfide or cadmium sulfide.
JP2001385517A 2001-12-19 2001-12-19 Thin film-like photocatalyst, forming method thereof, method of treating hydrogen sulfide using the thin film- like photocatalyst, and method of manufacturing hydrogen Pending JP2003181297A (en)

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* Cited by examiner, † Cited by third party
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JP2005093974A (en) * 2003-09-18 2005-04-07 Ind Technol Res Inst Semiconductor material for active layer of thin film transistor element and its manufacturing method
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WO2006106784A1 (en) * 2005-03-31 2006-10-12 Nittetsu Mining Co., Ltd. Method for processing hydrogen sulfide, method for producing hydrogen and photocatalyst reactor
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