JP2001259436A - Fe2O3 PHOTOCATALYST COMPONENT, PHOTOCATALYST AND METHOD OF REMOVING NITROGEN OXIDE IN AIR - Google Patents
Fe2O3 PHOTOCATALYST COMPONENT, PHOTOCATALYST AND METHOD OF REMOVING NITROGEN OXIDE IN AIRInfo
- Publication number
- JP2001259436A JP2001259436A JP2000075552A JP2000075552A JP2001259436A JP 2001259436 A JP2001259436 A JP 2001259436A JP 2000075552 A JP2000075552 A JP 2000075552A JP 2000075552 A JP2000075552 A JP 2000075552A JP 2001259436 A JP2001259436 A JP 2001259436A
- Authority
- JP
- Japan
- Prior art keywords
- photocatalyst
- air
- component
- nitrogen oxides
- denitration
- 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
Links
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 title claims abstract description 112
- 239000011941 photocatalyst Substances 0.000 title claims abstract description 32
- 238000000034 method Methods 0.000 title claims abstract description 14
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 title abstract 2
- 239000013078 crystal Substances 0.000 claims abstract description 9
- 238000004438 BET method Methods 0.000 claims abstract description 5
- 229910002651 NO3 Inorganic materials 0.000 claims description 12
- 230000001699 photocatalysis Effects 0.000 claims description 11
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 7
- 230000000802 nitrating effect Effects 0.000 claims description 4
- 230000001678 irradiating effect Effects 0.000 abstract description 2
- 150000004767 nitrides Chemical class 0.000 abstract 1
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 33
- 238000012360 testing method Methods 0.000 description 18
- 239000003054 catalyst Substances 0.000 description 11
- -1 hydroxyl radicals Chemical class 0.000 description 11
- 229910010413 TiO 2 Inorganic materials 0.000 description 10
- 238000006243 chemical reaction Methods 0.000 description 10
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 239000000843 powder Substances 0.000 description 8
- 230000001590 oxidative effect Effects 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 230000003197 catalytic effect Effects 0.000 description 5
- 238000007254 oxidation reaction Methods 0.000 description 5
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 4
- 239000011230 binding agent Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 239000007789 gas Substances 0.000 description 4
- 229910017604 nitric acid Inorganic materials 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 239000003973 paint Substances 0.000 description 4
- 238000006722 reduction reaction Methods 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 238000005215 recombination Methods 0.000 description 3
- 230000006798 recombination Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 238000006862 quantum yield reaction Methods 0.000 description 2
- 239000003642 reactive oxygen metabolite Substances 0.000 description 2
- 230000003595 spectral effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 102100033041 Carbonic anhydrase 13 Human genes 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 101000867860 Homo sapiens Carbonic anhydrase 13 Proteins 0.000 description 1
- 229910002089 NOx Inorganic materials 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 238000003916 acid precipitation Methods 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000006297 dehydration reaction Methods 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 229960002089 ferrous chloride Drugs 0.000 description 1
- 239000011790 ferrous sulphate Substances 0.000 description 1
- 235000003891 ferrous sulphate Nutrition 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910052598 goethite Inorganic materials 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910052595 hematite Inorganic materials 0.000 description 1
- 239000011019 hematite Substances 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- AEIXRCIKZIZYPM-UHFFFAOYSA-M hydroxy(oxo)iron Chemical compound [O][Fe]O AEIXRCIKZIZYPM-UHFFFAOYSA-M 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 150000002505 iron Chemical class 0.000 description 1
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- LIKBJVNGSGBSGK-UHFFFAOYSA-N iron(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Fe+3].[Fe+3] LIKBJVNGSGBSGK-UHFFFAOYSA-N 0.000 description 1
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 1
- 210000002429 large intestine Anatomy 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 230000033116 oxidation-reduction process Effects 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 238000007146 photocatalysis Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 208000023504 respiratory system disease Diseases 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、空気中ＮＯx の硝
酸化除去に有用な脱硝用光触媒成分、これを含む脱硝用
光触媒、および該光触媒を用いた可視光照射、常温下で
の空気中窒素酸化物の除去方法に関する。The present invention relates to the useful denitration photocatalytic component nitrating removal in air NO x, visible light irradiation, in air at room temperature using a denitration photocatalytic, and the photocatalyst containing this The present invention relates to a method for removing nitrogen oxides.
【０００２】[0002]
【従来の技術】一酸化窒素ＮＯ、二酸化窒素ＮＯ2 など
のガス状窒素酸化物（ＮＯx ）は大気中に放出される
と、人体に呼吸器疾患を誘因したり、光化学スモッグ、
酸性雨などの原因となる。そのため自動車、発電所など
の発生源から大気中に放出される窒素酸化物量は規制さ
れ、二酸化窒素については環境基準が定められてはいる
が、その目標は必ずしも達成されているとはいえない。
とくに自動車道路沿道などでは依然として基準濃度を越
える窒素酸化物が観測されており、その早急な解決が切
望されている。2. Description of the Related Art Gaseous nitrogen oxides (NO x ) such as nitric oxide NO and nitrogen dioxide NO 2 , when released into the atmosphere, can cause respiratory diseases in the human body, cause photochemical smog,
May cause acid rain. Therefore, the amount of nitrogen oxides emitted into the atmosphere from sources such as automobiles and power plants is regulated, and environmental standards for nitrogen dioxide have been set, but the target has not always been achieved.
In particular, nitrogen oxides exceeding the standard concentration are still observed on roadsides and the like, and an urgent solution is urgently needed.
【０００３】大気中の窒素酸化物はＮＯを主成分として
おり、大気中の酸素により酸化され硝酸として大気中か
ら自然除去されるが、大気中窒素酸化物ＮＯx 濃度がｐ
ｐｍオーダーになるとその除去には数日間も要する。こ
のため大気中からＮＯx を早急に除去するために触媒の
利用が盛んに検討されている。[0003] nitrogen oxides in the atmosphere is mainly composed of NO, but is naturally removed from the atmosphere as nitric acid is oxidized by oxygen in atmosphere, the nitrogen oxides concentration of NO x in the atmosphere p
Removal in the pm order takes several days. Use of the catalyst has been extensively studied in order to quickly remove the NO x from the order in the air.
【０００４】従来、自動車、発電所などの特定燃焼発生
源からの排出ガスについては、ＮＨ 3 による無触媒還元
法、ＨＣ，Ｃ，ＣＯなどの還元物質を利用する炉内脱硝
法などの脱硝法により高濃度の窒素酸化物量を低減する
方法が知られている。このような燃焼源に用いるための
ＰｄやＰｔなどの酸化あるいは還元触媒も提案されてい
る。しかしながらこれらの脱硝法は、還元物質を共存さ
せる必要があるなどの使用上の制約もあり、また脱硝触
媒は比較的高温で性能を発揮するように開発されてお
り、大気中に設置して使用するにはエネルギーコストな
どがかかるなどして現実的に困難である。Conventionally, generation of specific combustion in automobiles, power plants, etc.
For emissions from sources, NH ThreeWithout catalyst
Denitration in furnaces using reducing substances such as HC, C, and CO
Reduction of high concentration of nitrogen oxides by denitrification method
Methods are known. For use in such combustion sources
Oxidation or reduction catalysts such as Pd and Pt have also been proposed.
You. However, these denitration methods do not coexist with reducing substances.
There are also restrictions on use such as the need to remove
The medium has been developed to perform at relatively high temperatures.
Energy cost to install and use in the atmosphere.
It is practically difficult because of the throat.
【０００５】ところで近年、光照射により半導体特性を
示し、窒素酸化物を酸化のための脱硝触媒となりうる光
触媒が着目され、実用化に向けた研究が盛んに検討され
ている。すなわち図１に示すように、半導体のバンドギ
ャップに相当するエネルギーの光が照射されると、荷電
子帯上端の電子が伝導帯下端のエネルギー準位に励起さ
れ、荷電子帯には正孔が生成する。この時、荷電子帯の
正孔は外部から電子を受容して酸化反応を、伝導帯に励
起された電子は外部に移行して還元反応を起こし得る。In recent years, attention has been paid to photocatalysts which exhibit semiconductor characteristics by light irradiation and can be used as denitration catalysts for oxidizing nitrogen oxides, and studies for practical use are being actively studied. That is, as shown in FIG. 1, when light having energy corresponding to the band gap of a semiconductor is irradiated, electrons at the upper end of the valence band are excited to the energy level at the lower end of the conduction band, and holes are formed in the valence band. Generate. At this time, holes in the valence band may receive an electron from the outside to cause an oxidation reaction, and electrons excited in the conduction band may transfer to the outside to cause a reduction reaction.
【０００６】とくにアナタースＴｉＯ2 は、光照射によ
り励起された時の伝導帯下端のエネルギー準位（電位）
は−０．２Ｖ（vsＮＨＥ）付近である。この励起された
ＴｉＯ2 表面では、空気中の酸素ガス分子の還元反応が
生起し、水酸基ラジカルあるいはスーパーオキサイドイ
オンなどの活性酸素種が生成される。 ｅ cb - + Ｏ2 + Ｈ+ →ＨＯ2 ・…（１） （標準酸化還元電位Ｅ0 ＝−０．１５Ｖ（vsＮＨＥ））In particular, anatase TiO 2 is an energy level (potential) at the bottom of the conduction band when excited by light irradiation.
Is around -0.2 V (vs NHE). On the excited TiO 2 surface, a reduction reaction of oxygen gas molecules in the air occurs, and active oxygen species such as hydroxyl radicals or superoxide ions are generated. e cb- + O 2 + H + → HO 2 ··· (1) (standard oxidation-reduction potential E 0 = −0.15 V (vs NHE))
【０００７】この活性酸素種は強力な酸化作用を有する
ため、これを利用すれば大気中のＮＯx を短時間で硝酸
まで酸化し、除去することが可能である。またＴｉＯ2
は、荷電子帯に生成する正孔電位が約＋３．０Ｖ（vsＮ
ＨＥ）であり、下記式（２）で示されるＮＯガスの硝酸
イオン化反応も進行する。 ＮＯ3 - ＋４Ｈ+ ＋３ｅ- ＝ＮＯ（ｇ）＋２Ｈ2 Ｏ …（２） （標準酸化還元電位Ｅ0 ＝＋０．９６Ｖ（vsＮＨＥ））[0007] Therefore reactive oxygen species having a strong oxidizing action, which oxidizes to nitrate the NO x in the atmosphere in a short time by utilizing, can be removed. TiO 2
Indicates that the hole potential generated in the valence band is about +3.0 V (vsN
HE), and the nitric acid ionization reaction of the NO gas represented by the following formula (2) also proceeds. NO 3 − + 4H + + 3e − = NO (g) + 2H 2 O (2) (standard redox potential E 0 = + 0.96 V (vs NHE))
【０００８】ＴｉＯ2 光触媒は、紫外光照射下、常温で
触媒効果を発現でき、かつ複雑な装置を必要としないな
ど経済的にも画期的であり、自動車道路沿道、トンネル
あるいは室内などの窒素酸化物汚染が問題となる空間に
設置するものとして有用であると考えられる。したがっ
てこの実用化方法が多く提案され、たとえば、ＴｉＯ2
と活性炭との混合物を３００ｎｍ以上の入工光あるいは
太腸光を照射して光触媒作用させ、空気中の窒素酸化物
を酸化し、硝酸として固定化する方法（特公平２−６２
２９７号）などが提案されている。[0008] The TiO 2 photocatalyst can exhibit a catalytic effect at room temperature under ultraviolet light irradiation, and is economically revolutionary because it does not require a complicated device. It is considered to be useful as an installation in a space where oxide contamination is a problem. Therefore, many practical methods have been proposed, for example, TiO 2
A method of irradiating a mixture of activated carbon with activated light or a large intestine light of 300 nm or more to cause photocatalysis to oxidize nitrogen oxides in the air and to fix them as nitric acid (Japanese Patent Publication No. 2-62).
297) has been proposed.
【０００９】しかしながらＴｉＯ2 のバンドギャップが
５．１２７×１０-19 Ｊ（３．２ｅＶ）であり（図１参
照）、反応に利用できる光はこのバンドギャップに相当
する波長の光すなわち３８７ｎｍ以下の高エネルギー紫
外光に限られる。このため可視光領域の光を吸収するこ
とはできず、太陽光のうち利用できる波長領域はごくわ
ずかであり、特に日照量の少ない場所では充分に触媒効
果が発現できないという問題点がある。また上記ＴｉＯ
2 表面に生成する活性酸素種の酸化作用は強力であり、
窒素酸化物の酸化だけでなくほとんどすべての有機物質
を分解する能力を有する。このため共存樹脂を分解する
という問題があり、たとえば塗料形態で使用した場合に
はＴｉＯ2 塗料の塗膜で起きるチョーキング現象のよう
に樹脂皮膜の表面を劣化させるなど、フッ素樹脂などの
ごく一部を除き使用することができず、ＴｉＯ2光触媒
実用化への障害の一つになっている。However, the band gap of TiO 2 is 5.127 × 10 −19 J (3.2 eV) (see FIG. 1), and the light available for the reaction is light of a wavelength corresponding to this band gap, that is, light of 387 nm or less. Limited to high energy UV light. For this reason, light in the visible light region cannot be absorbed, and the available wavelength region of sunlight is very small. In particular, there is a problem that a catalytic effect cannot be sufficiently exhibited in a place with a small amount of sunlight. The above TiO
2 The oxidizing effect of reactive oxygen species generated on the surface is strong,
It has the ability to decompose almost all organic substances as well as oxidize nitrogen oxides. For this reason, there is a problem that the coexisting resin is decomposed. For example, when used in the form of a paint, the surface of the resin film is deteriorated like a choking phenomenon that occurs in the coating film of the TiO 2 paint. TiO 2 photocatalyst is one of the obstacles to practical use.
【００１０】[0010]
【発明が解決しようとする課題】上記ＴｉＯ2 以外に、
理論上光触媒となりうるものとしてＦｅ2 Ｏ3 も知られ
ている。Ｆｅ2 Ｏ3 の荷電子帯に生成する正孔の電位は
約２．６Ｖ（vsＮＨＥ）であり、上記式（２）で示され
るＮＯガスの硝酸イオン化反応（Ｅ0 ＝＋０．９６Ｖ
（vsＮＨＥ））は充分に進行する。In addition to the above TiO 2 ,
Fe 2 O 3 is also known as a photocatalyst in theory. The potential of holes generated in the valence band of Fe 2 O 3 is about 2.6 V (vs NHE), and the nitric acid ionization reaction of NO gas (E 0 = + 0.96 V) represented by the above formula (2)
(VsNHE)) proceeds sufficiently.
【００１１】このＦｅ2 Ｏ3 のバンドギャップは３．６
８５×１０-19 Ｊ（２．３ｅＶ）であり、波長５３９ｎ
ｍ以下の光で伝導帯に励起される、すなわち可視光吸収
が可能である。またＦｅ2 Ｏ3 の伝導帯下端のエネルギ
ー準位は、＋０．３Ｖ（vsＮＨＥ）付近であり、ＴｉＯ
2 （−０．２Ｖ）に比べて還元力が弱く、上記式 (１）
で示されるような活性酸素種を生成する還元反応は起き
ない。したがってＦｅ2 Ｏ3 は、常温での可視光照射に
よりガス状窒素酸化物を酸化（硝酸化）することが可能
であり、しかも共存する有機物の分解は起きないので、
樹脂などをバインダーとして塗料形態で使用することも
可能である。The band gap of this Fe 2 O 3 is 3.6.
85 × 10 −19 J (2.3 eV), wavelength 539 n
It is excited in the conduction band by light of m or less, that is, visible light absorption is possible. The energy level at the lower end of the conduction band of Fe 2 O 3 is around +0.3 V (vs NHE),
2 The reducing power is weaker than that of (-0.2V).
Does not occur. Therefore, Fe 2 O 3 can oxidize (nitrate) gaseous nitrogen oxides by irradiation with visible light at normal temperature, and furthermore, the coexisting organic matter does not decompose.
It is also possible to use a resin or the like as a binder in the form of a paint.
【００１２】上記のようにＦｅ2 Ｏ3 は、理論的には窒
素酸化物の酸化のための光触媒となりうることは可能で
あるが、実際にＦｅ2 Ｏ3 表面でＮＯガスが硝酸イオン
にまで酸化される反応が起こるかどうかは他の要因にも
左右される。中でも、一旦吸収光のエネルギーにより励
起した電子と正孔とが、再結合ではなく外部の物質と何
らかの反応を起こす確率（量子収率）がどの程度起きる
かという点が極めて重要であるが、一般に光触媒の表面
に励起された電子や正孔が再結合する前に反応を起こす
確率は低い。とくにＦｅ2 Ｏ3 の量子収率はきわめて低
く、理論上その電位から起こり得ると期待される反応が
現実には起こらないケースが多い。空気中の窒素酸化物
の酸化にＦｅ2 Ｏ3 が適用された報告例は少なく、これ
までのところ、実用上十分な反応速度でＦｅ2 Ｏ3 表面
での光触媒反応によって空気中の窒素酸化物を酸化除去
できた例は無かった。As described above, it is theoretically possible that Fe 2 O 3 can serve as a photocatalyst for the oxidation of nitrogen oxides, but in fact NO gas is converted to nitrate ions on the surface of Fe 2 O 3. Whether or not the oxidizing reaction takes place depends on other factors. Among them, it is extremely important to determine the probability (quantum yield) that electrons and holes, once excited by the energy of absorbed light, cause some reaction with an external substance instead of recombination. The probability that electrons or holes excited on the surface of the photocatalyst will react before recombination is low. In particular, the quantum yield of Fe 2 O 3 is extremely low, and in many cases, a reaction that is theoretically expected to occur from that potential does not actually occur. There have been few reports of the application of Fe 2 O 3 to the oxidation of nitrogen oxides in air. So far, nitrogen oxides in air have been photocatalyzed on the surface of Fe 2 O 3 at a reaction rate sufficient for practical use. There was no example that could be removed by oxidation.
【００１３】[0013]
【課題を解決するための手段】本発明者は、上記のよう
に理論的には窒素酸化物の酸化触媒となりうるが、実用
化はされてなかった光触媒成分Ｆｅ2 Ｏ3 に着目し、こ
れを光触媒として実用化すべく検討したところ、Ｆｅ2
Ｏ3 をアモルファス化することなくα結晶性を保持し、
かつ該結晶粒を微細化することにより、再結合の場とな
る欠陥を極力低減することができ、量子効率を向上させ
ることができることを見出した。そしてこのα結晶粒の
微細化としてＦｅ2 Ｏ3 の比表面積を目安とすることが
でき、図２に示すようにＦｅ2 Ｏ3 の比表面積が２０ｍ
2 ／ｇという特定値以上になると光触媒活性が飛躍的に
向上し、光触媒として有用な効果が得られることを見出
して本発明を完成した。The present inventor has focused on the photocatalyst component Fe 2 O 3 which could theoretically be used as a catalyst for oxidizing nitrogen oxides as described above, but has not been put to practical use. It was studies to practical use as a photocatalyst, Fe 2
Retains α crystallinity without amorphizing O 3 ,
In addition, it has been found that by making the crystal grains fine, defects serving as a recombination field can be reduced as much as possible, and quantum efficiency can be improved. And only an estimate of the specific surface area of Fe 2 O 3 as a refining of the α crystal grains, the specific surface area of the Fe 2 O 3 as shown in FIG. 2 20 m
When the specific value of 2 / g or more was reached, the photocatalytic activity was dramatically improved, and it was found that a useful effect as a photocatalyst could be obtained, thereby completing the present invention.
【００１４】すなわち本発明では、ＢＥＴ法で測定され
る比表面積が２０ｍ2 ／ｇ以上で、実質的にα結晶Ｆｅ
2 Ｏ3 からなる脱硝用光触媒成分が提供される。またこ
の光触媒成分を含む、空気中からガス状窒素酸化物を硝
酸化するための脱硝用光触媒が提供される。That is, in the present invention, when the specific surface area measured by the BET method is 20 m 2 / g or more, the α-crystal Fe
A denitration photocatalytic component comprising 2 O 3 is provided. Also provided is a denitration photocatalyst for nitrating gaseous nitrogen oxides from air, which contains the photocatalyst component.
【００１５】また本発明に係る空気中窒素酸化物の除去
方法は、５３９ｎｍ以下の波長の光成分を含む光の下
で、上記光触媒成分とガス状窒素酸化物を含む空気とを
接触させ、ガス状窒素酸化物を硝酸化することを特徴と
している。上記接触は、常温下で行うことができる。Further, the method for removing nitrogen oxides in air according to the present invention comprises contacting the photocatalyst component with air containing gaseous nitrogen oxide under light containing a light component having a wavelength of 539 nm or less. It is characterized by nitrating nitric oxide. The contact can be performed at normal temperature.
【００１６】[0016]
【発明の実施の形態】本発明の光触媒成分は、ＢＥＴ法
で測定される比表面積（以下、ＢＥＴ比表面積とも称
す）が２０ｍ2 ／ｇ以上、好ましくは５０ｍ2 ／ｇ以
上、より好ましくは５０〜２００ｍ2 ／ｇのＦｅ2 Ｏ3
粉末からなる。なお、ＢＥＴ法では液体窒素を用いて測
定した。上記比表面積を持つＦｅ2 Ｏ3 は、実質的にα
結晶の微細粒子である。またアモルファス態は実質的に
含まない。BEST MODE FOR CARRYING OUT THE INVENTION The photocatalytic component of the present invention has a specific surface area (hereinafter, also referred to as a BET specific surface area) measured by the BET method of at least 20 m 2 / g, preferably at least 50 m 2 / g, more preferably at least 50 m 2 / g. 200 m 2 / g of Fe 2 O 3
Consists of powder. In the BET method, measurement was performed using liquid nitrogen. Fe 2 O 3 having the above specific surface area is substantially α
It is a fine crystal particle. The amorphous state is not substantially contained.
【００１７】このようなＦｅ2 Ｏ3 は、波長５３９ｎｍ
以下の光照射により荷電子帯に正孔を生成することがで
きる。その正孔電位は約２．６Ｖ（vsＮＨＥ）であり、
たとえば式（２）で示される反応を左辺側に進行させ、
空気中のガス状窒素酸化物を酸化（硝酸化）し、脱硝効
果を発揮することができる。 ＮＯ3 - ＋４Ｈ+ ＋３ｅ- ＝ＮＯ（ｇ）＋２Ｈ2 Ｏ …（２）Such Fe 2 O 3 has a wavelength of 539 nm.
Holes can be generated in the valence band by the following light irradiation. Its hole potential is about 2.6 V (vs NHE),
For example, the reaction represented by the formula (2) proceeds to the left side,
It oxidizes (nitrates) gaseous nitrogen oxides in the air and can exert a denitration effect. NO 3 − + 4H + + 3e − = NO (g) + 2H 2 O (2)
【００１８】Ｆｅ2 Ｏ3 に触媒作用させる光源は、５３
９ｎｍまでの波長成分を含む光であればよく、太陽光で
もよく、人工の可視光および／または紫外光、いずれで
あってもよい。またＦｅ2 Ｏ3 は、常温で光触媒効果を
発揮することができる。The light source for catalyzing Fe 2 O 3 is 53
Any light containing a wavelength component of up to 9 nm may be used, and sunlight may be used, and any of artificial visible light and / or ultraviolet light may be used. Further, Fe 2 O 3 can exert a photocatalytic effect at normal temperature.
【００１９】上記のようなＦｅ2 Ｏ3 は、たとえば２価
鉄イオンを含む溶液にアルカリを加えゲーサイトの沈殿
を生成し、その後、加熱脱水することによりヘマタイト
とする方法などで製造することができる。The above-mentioned Fe 2 O 3 can be produced, for example, by a method of adding an alkali to a solution containing ferrous iron ions to form a precipitate of goethite, followed by heating and dehydration to obtain hematite. it can.
【００２０】また上記反応（２）により酸化された空気
中のガス状窒素酸化物は、硝酸イオンとしてＦｅ2 Ｏ3
表面に固定化される。上記のようなＦｅ2 Ｏ3 は、通常
粉末状であり脱硝用触媒成分としてそのままで使用する
ことも可能であるが、他の触媒助剤とともに光触媒を形
成することもできる。The gaseous nitrogen oxide in the air oxidized by the above reaction (2) is converted into nitrate ions by Fe 2 O 3
Immobilized on the surface. The above-mentioned Fe 2 O 3 is usually in the form of powder and can be used as it is as a denitration catalyst component, but it can also form a photocatalyst together with other catalyst auxiliaries.
【００２１】またたとえば樹脂バインダーなどとともに
塗料形態で使用すると実用上有用である。この際、光照
射により励起されたＦｅ2 Ｏ3 の伝導帯下端のケミカル
ポテンシャルでは炭化水素化合物を分解しないため、Ｔ
ｉＯ2 光触媒の場合に対して有機樹脂バインダーが制限
されないという利点がある。It is practically useful to use it in the form of a paint together with, for example, a resin binder. At this time, the hydrocarbon compound is not decomposed at the chemical potential at the lower end of the conduction band of Fe 2 O 3 excited by light irradiation.
There is an advantage that the organic resin binder is not limited as compared with the case of the iO 2 photocatalyst.
【００２２】Ｆｅ2 Ｏ3 光触媒成分を用いて、空気中の
ガス状窒素酸化物を硝酸化し除去するには、５３９ｎｍ
以下の波長の光成分を含む光の下で、光触媒成分とガス
状窒素酸化物（ＮＯX ）を含む空気とを接触させればよ
く、その方法は特に限定されない。In order to nitrify and remove gaseous nitrogen oxides in the air using the Fe 2 O 3 photocatalyst component, 539 nm
Under light including a light component of a wavelength, may be contacted with the air containing photocatalyst component gaseous nitrogen oxide (NO X), the method is not particularly limited.
【００２３】[0023]
【実施例】次に本発明を実施例により具体的に説明する
が、本発明はこれら実施例に限定されるものではない。 （実施例１） ＜光触媒の調製＞容積１５リットルの反応容器中に、８
ＮのＮａＯＨ溶液２リットルおよび硫酸第１鉄０．５ｍ
ｏｌを含む鉄塩溶液８リットルを加えて混合し、４０℃
で空気を２リットル／ｍｉｎの速度で通気してα−Ｆｅ
ＯＯＨ粒子を生成した。生成した粒子は、水洗・ろ過・
解砕した後、さらに空気中で３００℃×１分間加熱し、
Ｆｅ2 Ｏ3 粉末を得た。ＮａＯＨとＦｅＣｌ3 の混合比
ＰＨなどを変えることで比表面積を変化させ、ＢＥＴ比
表面積２０、３０、５０、６５ｍ2 ／ｇのＦｅ2 Ｏ3 粉
末を得た。これらのサンプルをＸ線回折で調べた結果、
いずれもα結晶であった。EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. (Example 1) <Preparation of photocatalyst> In a 15-liter reaction vessel, 8
2 L of NaOH solution of N and 0.5 m of ferrous sulfate
8 liters of an iron salt solution containing
And aeration of air at a rate of 2 liters / min.
OOH particles were produced. The generated particles are washed, filtered,
After crushing, further heat in air at 300 ° C for 1 minute,
An Fe 2 O 3 powder was obtained. The specific surface area was changed by changing the mixing ratio PH of NaOH and FeCl 3 to obtain Fe 2 O 3 powders having BET specific surface areas of 20, 30, 50, and 65 m 2 / g. As a result of examining these samples by X-ray diffraction,
All were α crystals.
【００２４】＜試験装置＞図３に、窒素酸化物（以後Ｎ
Ｏｘ）除去試験に用いた装置を模式的に示す。市販のス
テンレス製グローブボックスの外部に、光源となる蛍光
管を固定し、グローブボックスのガラス窓を通して内部
の試料台に固定した試験片に光を照射した。グローブボ
ックス内は５ｐｐｍ−ＮＯ雰囲気とし、外部に設置した
ポンプを通じて循環させた。図３の装置を暗所に設置し
て、光源以外の外部からの光は試料に届かないように制
御した。<Testing Apparatus> FIG. 3 shows a nitrogen oxide (hereinafter referred to as N).
Ox) The apparatus used for the removal test is schematically shown. A fluorescent tube serving as a light source was fixed to the outside of a commercially available stainless steel glove box, and light was applied to a test piece fixed to an internal sample table through a glass window of the glove box. The glove box was set to a 5 ppm-NO atmosphere and circulated through a pump installed outside. The apparatus shown in FIG. 3 was installed in a dark place, and was controlled so that external light other than the light source did not reach the sample.
【００２５】＜光 源＞試験に用いた２光源の分光特性
を図４に示す。 可視光光源として、波長５４０ｎｍ付近にピークを
もつ蛍光灯（ナショナル製ＦＬ１０Ｇ）を用いた。 紫外光光源として、波長３５０ｎｍ付近にピークを
持つ蛍光灯（ナショナル製ＦＬ１０ＢＬ−Ｂ）を用い
た。<Light Source> FIG. 4 shows the spectral characteristics of the two light sources used in the test. As a visible light source, a fluorescent lamp (FL10G manufactured by National) having a peak near a wavelength of 540 nm was used. A fluorescent lamp (FL10BL-B manufactured by National) having a peak near a wavelength of 350 nm was used as an ultraviolet light source.
【００２６】＜試 験＞ （１）試験片の作成 実施例、比較例で得られたＦｅ2 Ｏ3 粉末を、ＳＵＳ４
３０板の１００ｍｍ×５０ｍｍ×０．５ｍｍ切出片の片
面上に、５ｇ／ｍ2 の担持量で貼付けた両面テープ上に
まぶして固定し、試験片を作成した。<Tests> (1) Preparation of Test Specimens Fe 2 O 3 powders obtained in Examples and Comparative Examples were
A test piece was prepared by covering 30 pieces of 100 mm × 50 mm × 0.5 mm cut pieces on one side with a double-sided tape adhered at a carrying amount of 5 g / m 2 on one side.
【００２７】（２）上記で得られた試験片を、図３に示
す試験装置内に固定し、５ｐｐｍのＮＯガスを循環させ
ながら、室温で１２時間光照射した。 （３）次に装置から取出した上記試験片を、２０ｍＬの
脱イオン水中に浸漬し、３時間静置した後、試験片の表
面に固定化された硝酸イオンを脱イオン水中に抽出し
た。 （４）硝酸イオン選択性電極（ＯＲＩＯＮ社製９７０
７）を用いて抽出液中の硝酸イオン（ＮＯ3 - ）濃度を
分析した。 上記手順により、同一塗布量のときの単位面積あたりに
固定化された硝酸イオン濃度（ＮＯ3 - 固定化量）を測
定し、各比表面積の光触媒成分に対する窒素酸化物の酸
化能力（脱硝能力）を調べた。(2) The test piece obtained above was fixed in the test apparatus shown in FIG. 3 and irradiated with light at room temperature for 12 hours while circulating 5 ppm of NO gas. (3) Next, the test piece taken out of the apparatus was immersed in 20 mL of deionized water, allowed to stand for 3 hours, and then nitrate ions immobilized on the surface of the test piece were extracted into the deionized water. (4) Nitrate ion selective electrode (970 manufactured by ORION)
Using 7), the concentration of nitrate ion (NO 3 − ) in the extract was analyzed. By the above procedure, the immobilized nitrate ion concentration per unit area when the same coating amount - measured (NO 3 immobilization amount), oxidative capacity of nitrogen oxide to the photocatalyst component of the specific surface area (denitrification capability) Was examined.
【００２８】＜試験結果＞図２に、Ｆｅ2 Ｏ3 の比表面
積（横軸）と、硝酸イオン固定化濃度（縦軸）との関係
を示す。<Test Results> FIG. 2 shows the relationship between the specific surface area of Fe 2 O 3 (horizontal axis) and the concentration of fixed nitrate ions (vertical axis).
【００２９】（比較例１）ＮａＯＨとＦｅＣｌ3 の混合
比を変えた以外は、実施例１と同様の湿式調製法により
得られたＢＥＴ比表面積５、１０、１５ｍ2 ／ｇのＦｅ
2 Ｏ3 粉末を試験に供した。Ｘ線回折の結果、いずれも
α結晶であった。実施例１と同様の試験を行い、結果を
図２に示す。(Comparative Example 1) BET specific surface areas of 5, 10, and 15 m 2 / g were obtained by the same wet preparation method as in Example 1 except that the mixing ratio of NaOH and FeCl 3 was changed.
2 O 3 powder was subjected to the test. As a result of X-ray diffraction, all were α crystals. The same test as in Example 1 was performed, and the results are shown in FIG.
【００３０】（比較例２）塩化第１鉄水溶液を６５０℃
で噴霧焙焼して得られたＢＥＴ比表面積５ｍ2 ／ｇのＦ
ｅ2 Ｏ3 粉末（市販品；川崎製鉄製フェライト用原料）
を用いた。Ｘ線回折の結果、α結晶であった。実施例１
と同様の試験を行い、結果を図２に示す。図２の硝酸イ
オン固定化濃度から明らかなように、比表面積２０ｍ2
／ｇ未満のＦｅ2 Ｏ3 では明確な触媒効果が得られない
のに対し、触媒効果は比表面積２０ｍ2 ／ｇで不連続的
に変化し、２０ｍ2 ／ｇを境に飛躍的に向上している。
本発明の２０ｍ2 ／ｇ以上の比表面積を有する実施例Ｆ
ｅ2 Ｏ3 光触媒成分は、空気中のＮＯｘを酸化して硝酸
イオンとして表面に保持するような光触媒効果（脱硝触
媒）を十分に示すことが分かる。Comparative Example 2 An aqueous solution of ferrous chloride was heated at 650 ° C.
With a BET specific surface area of 5 m 2 / g obtained by spray roasting
e 2 O 3 powder (commercially available; raw material for ferrite made by Kawasaki Steel)
Was used. As a result of X-ray diffraction, it was an α crystal. Example 1
A test similar to the above was performed, and the results are shown in FIG. As is apparent from the nitrate ion-immobilized concentration in FIG. 2, the specific surface area was 20 m 2.
/ In Fe 2 O 3 of less than g contrast is not obtained clear catalytic effect, catalytic effect is discontinuously varied specific surface area 20 m 2 / g, and dramatically improved in the boundary of 20 m 2 / g ing.
Example F of the present invention having a specific surface area of 20 m 2 / g or more
It can be seen that the e 2 O 3 photocatalyst component sufficiently exhibits a photocatalytic effect (deNOx catalyst) such that NOx in the air is oxidized and held on the surface as nitrate ions.
【００３１】（実施例２）実施例１のＢＥＴ比表面積５
０ｍ2 ／ｇのＦｅ2 Ｏ3 粉末について、単位面積あたり
の担持量を変化させた以外は、実施例１と同様にして光
触媒効果を調べた。試験結果を図５に示す。光照射無し
でも少量の硝酸イオンを検出することができたが、光照
射によって硝酸イオン固定化量が急激に増加し、この光
源は可視光であっても紫外光であってもほぼ同等であっ
た。(Example 2) BET specific surface area 5 of Example 1
The photocatalytic effect was examined in the same manner as in Example 1 except that the amount of Fe 2 O 3 powder of 0 m 2 / g was changed per unit area. The test results are shown in FIG. Although a small amount of nitrate ions could be detected without light irradiation, the amount of immobilized nitrate ions rapidly increased by light irradiation, and this light source was almost the same regardless of whether it was visible light or ultraviolet light. Was.
【００３２】[0032]
【発明の効果】上記のように本発明では、可視光照射
下、常温で光触媒効果のあるＦｅ2 Ｏ3を触媒成分とし
て実用上使用可能にすることができた。この触媒成分に
よれば、大気中の窒素酸化物を除去したい空間に置くだ
けで、空気中の窒素酸化物を硝酸化し、脱硝することが
できる。また該触媒成分は、共存する有機物は本質的に
分解しないので、樹脂バインダーなどを制限なく用いて
塗料形態とすることができ、その利用範囲も広い。As described above, according to the present invention, Fe 2 O 3 having a photocatalytic effect at room temperature under irradiation with visible light can be practically used as a catalyst component. According to this catalyst component, nitrogen oxides in the air can be nitrated and denitrated simply by placing them in a space where nitrogen oxides in the air are to be removed. In addition, since the coexisting organic substance does not essentially decompose, the catalyst component can be formed into a coating form using a resin binder or the like without limitation, and its use range is wide.
【図１】 半導体のエネルギー特性を説明する図であ
る。FIG. 1 is a diagram illustrating energy characteristics of a semiconductor.
【図２】 Ｆｅ2 Ｏ3 のＢＥＴ比表面積に対する硝酸イ
オン固定化量を示す図である。FIG. 2 is a diagram showing the amount of nitrate ions immobilized on the BET specific surface area of Fe 2 O 3 .
【図３】 空気中のＮＯx 除去試験に用いた装置を示す
図である。3 is a diagram showing an apparatus used for NO x removal test in air.
【図４】 空気中のＮＯx 除去試験に用いた光源の分光
特性を示す図である。4 is a diagram showing spectral characteristics of the light source used for the NO x removal test in air.
【図５】 本発明のＦｅ2 Ｏ3 光触媒成分の単位面積あ
たりの担持量に対する触媒効果を示す図である。FIG. 5 is a graph showing the catalytic effect on the amount of Fe 2 O 3 photocatalyst component of the present invention carried per unit area.
フロントページの続き (72)発明者 田原 知之 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社技術研究所内 Ｆターム(参考） 4D048 AA06 BA36X BA36Y BA41X BA41Y BB17 EA01 4G002 AA03 AB02 AE05 4G069 AA02 AA12 AA15 BA48A BB04A BB04B BC66A BC66B CA13 EC01X EC01Y EC22X EC22Y Continuation of the front page (72) Inventor Tomoyuki Tahara 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba F-term in the Technical Research Laboratory, Kawasaki Steel Co., Ltd. 4D048 AA06 BA36X BA36Y BA41X BA41Y BB17 EA01 4G002 AA03 AB02 AE05 4G069 AA02 AA12 AA15 BA48A BB04A BB04B BC66A BC66B CA13 EC01X EC01Y EC22X EC22Y
Claims (4)
／ｇ以上で、実質的にα結晶Ｆｅ2Ｏ3 からなる脱硝用
光触媒成分。A specific surface area measured by a BET method is 20 m 2.
/ G or more, a photocatalytic component for denitration consisting essentially of α-crystal Fe 2 O 3 .
ス状窒素酸化物を硝酸化するための脱硝用光触媒。2. A denitration photocatalyst containing the photocatalyst component according to claim 1 for nitrating gaseous nitrogen oxides in air.
下で、請求項１に記載の光触媒成分とガス状窒素酸化物
を含む空気とを接触させ、ガス状窒素酸化物を硝酸化す
る、空気中窒素酸化物の除去方法。3. The photocatalyst component according to claim 1 is brought into contact with air containing gaseous nitrogen oxide under light containing a light component having a wavelength of 539 nm or less to nitrate the gaseous nitrogen oxide. , How to remove nitrogen oxides in the air.
空気中窒素酸化物の除去方法。4. The method for removing nitrogen oxides in air according to claim 3, wherein the contacting is performed at normal temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000075552A JP2001259436A (en) | 2000-03-17 | 2000-03-17 | Fe2O3 PHOTOCATALYST COMPONENT, PHOTOCATALYST AND METHOD OF REMOVING NITROGEN OXIDE IN AIR |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000075552A JP2001259436A (en) | 2000-03-17 | 2000-03-17 | Fe2O3 PHOTOCATALYST COMPONENT, PHOTOCATALYST AND METHOD OF REMOVING NITROGEN OXIDE IN AIR |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001259436A true JP2001259436A (en) | 2001-09-25 |
Family
ID=18593429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000075552A Pending JP2001259436A (en) | 2000-03-17 | 2000-03-17 | Fe2O3 PHOTOCATALYST COMPONENT, PHOTOCATALYST AND METHOD OF REMOVING NITROGEN OXIDE IN AIR |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001259436A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007075678A (en) * | 2005-09-12 | 2007-03-29 | National Institute Of Advanced Industrial & Technology | Zirconium oxide-based optically functional oxide |
| WO2007100039A1 (en) | 2006-03-01 | 2007-09-07 | Nissan Motor Co., Ltd. | Photocatalyst activation system and method for activating photocatalyst |
| EP2020504A2 (en) | 2007-08-02 | 2009-02-04 | Nissan Motor Co., Ltd. | Photocatalytic ignition system |
| JP2009233590A (en) * | 2008-03-27 | 2009-10-15 | National Institute Of Advanced Industrial & Technology | Toxic substance treatment method and device for treatment |
| CN102091620A (en) * | 2011-01-18 | 2011-06-15 | 上海交通大学 | Method for preparing porous hierarchical structure semiconductor photocatalytic material |
| JP2014152062A (en) * | 2013-02-07 | 2014-08-25 | Tokyo Metropolitan Univ | Photocatalytic glass |
| JP2015167871A (en) * | 2014-03-04 | 2015-09-28 | 公立大学法人首都大学東京 | Photocatalytic glass, and method of producing the same |
| JP2016209811A (en) * | 2015-05-08 | 2016-12-15 | 国立研究開発法人物質・材料研究機構 | Photocatalyst composite material and manufacturing method thereof |
-
2000
- 2000-03-17 JP JP2000075552A patent/JP2001259436A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007075678A (en) * | 2005-09-12 | 2007-03-29 | National Institute Of Advanced Industrial & Technology | Zirconium oxide-based optically functional oxide |
| JP4565239B2 (en) * | 2005-09-12 | 2010-10-20 | 独立行政法人産業技術総合研究所 | Zirconium oxide photofunctional oxide |
| WO2007100039A1 (en) | 2006-03-01 | 2007-09-07 | Nissan Motor Co., Ltd. | Photocatalyst activation system and method for activating photocatalyst |
| EP2020504A2 (en) | 2007-08-02 | 2009-02-04 | Nissan Motor Co., Ltd. | Photocatalytic ignition system |
| JP2009233590A (en) * | 2008-03-27 | 2009-10-15 | National Institute Of Advanced Industrial & Technology | Toxic substance treatment method and device for treatment |
| CN102091620A (en) * | 2011-01-18 | 2011-06-15 | 上海交通大学 | Method for preparing porous hierarchical structure semiconductor photocatalytic material |
| JP2014152062A (en) * | 2013-02-07 | 2014-08-25 | Tokyo Metropolitan Univ | Photocatalytic glass |
| JP2015167871A (en) * | 2014-03-04 | 2015-09-28 | 公立大学法人首都大学東京 | Photocatalytic glass, and method of producing the same |
| JP2016209811A (en) * | 2015-05-08 | 2016-12-15 | 国立研究開発法人物質・材料研究機構 | Photocatalyst composite material and manufacturing method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3790189B2 (en) | Novel synthesis method of visible light responsive BiVO4 fine powder, photocatalyst comprising the BiVO4 fine powder, and purification method using the photocatalyst | |
| EP0818239B1 (en) | Photocatalyst, method of producing the photocatalyst, and photocatalytic reaction method | |
| Shukla et al. | Activated carbon supported cobalt catalysts for advanced oxidation of organic contaminants in aqueous solution | |
| Hashimoto et al. | Photocatalytic oxidation of nitrogen oxide over titania–zeolite composite catalyst to remove nitrogen oxides in the atmosphere | |
| JP5582545B2 (en) | Photocatalyst containing carbon nitride, method for producing the same, and air purification method using the photocatalyst | |
| JP4018161B2 (en) | Method for producing titanium oxide for photocatalyst and method for removing harmful substances using the same | |
| EP1125636A1 (en) | Visible radiation type photocatalyst and production method thereof | |
| US20070193875A1 (en) | Photocatalyst materials having semiconductor characteristics and methods for manufacturing and using the same | |
| Chen et al. | Insights into designing photocatalysts for gaseous ammonia oxidation under visible light | |
| Li et al. | Efficient photocatalytic degradation of acrylonitrile by Sulfur-Bismuth co-doped F-TiO2/SiO2 nanopowder | |
| JP2001259436A (en) | Fe2O3 PHOTOCATALYST COMPONENT, PHOTOCATALYST AND METHOD OF REMOVING NITROGEN OXIDE IN AIR | |
| JP3742873B2 (en) | Photocatalyst, method for producing hydrogen using the same, and method for decomposing toxic substances | |
| JPH0262297B2 (en) | ||
| Santhosh et al. | Application of non-hierarchical gadolinium ortho-ferrite nanostructure for LED-driven photocatalytic mineralization of doxycycline hydrochloride | |
| JP4135907B2 (en) | Visible light active photocatalyst particles | |
| EP2617492A1 (en) | Glass with photocatalytic function | |
| JP3567004B2 (en) | Photocatalyst and method for producing the same | |
| JP2005254154A (en) | Visible light-responsive complex oxide type photocatalyst and toxic compound decomposing and removing method using the same | |
| EP0417538B1 (en) | Catalyst for reducing nitrogen oxides in a flue gas and method for producing said catalyst | |
| Zollo et al. | CN co-doped titanium dioxide. Key aspects in the assessment of the air pollutants abatement capability | |
| CN113797918B (en) | Defect-containing sandwich type perovskite catalyst and preparation method and application thereof | |
| JPH0532321B2 (en) | ||
| JPH04371228A (en) | Gold catalyst for removal of malodorous substance | |
| JP4147300B2 (en) | Nitrogen-containing titanium oxide photocatalyst and method for purifying environmental pollutant gas using the same | |
| JP3721430B2 (en) | Underwater organochlorine purification catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20060210 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20080821 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080826 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20090317 |