CN109647445B - MoS2Nanosheet-coated KNbO3Preparation method of nanowire piezoelectric/photocatalytic material - Google Patents
MoS2Nanosheet-coated KNbO3Preparation method of nanowire piezoelectric/photocatalytic material Download PDFInfo
- Publication number
- CN109647445B CN109647445B CN201910063881.4A CN201910063881A CN109647445B CN 109647445 B CN109647445 B CN 109647445B CN 201910063881 A CN201910063881 A CN 201910063881A CN 109647445 B CN109647445 B CN 109647445B
- Authority
- CN
- China
- Prior art keywords
- knbo
- mos
- nanowire
- piezoelectric
- photocatalytic material
- 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.)
- Active
Links
- 239000000463 material Substances 0.000 title claims abstract description 48
- 239000002070 nanowire Substances 0.000 title claims abstract description 47
- 230000001699 photocatalysis Effects 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims description 13
- 229910003334 KNbO3 Inorganic materials 0.000 claims abstract description 69
- 229910052961 molybdenite Inorganic materials 0.000 claims abstract description 66
- 229910052982 molybdenum disulfide Inorganic materials 0.000 claims abstract description 66
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims abstract description 27
- 239000002135 nanosheet Substances 0.000 claims abstract description 27
- 238000001027 hydrothermal synthesis Methods 0.000 claims abstract description 18
- 238000002360 preparation method Methods 0.000 claims abstract description 15
- XLYOFNOQVPJJNP-ZSJDYOACSA-N heavy water Substances [2H]O[2H] XLYOFNOQVPJJNP-ZSJDYOACSA-N 0.000 claims abstract description 9
- UMGDCJDMYOKAJW-UHFFFAOYSA-N thiourea Chemical compound NC(N)=S UMGDCJDMYOKAJW-UHFFFAOYSA-N 0.000 claims abstract description 9
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910015667 MoO4 Inorganic materials 0.000 claims abstract description 6
- 239000011734 sodium Substances 0.000 claims abstract description 6
- 239000011684 sodium molybdate Substances 0.000 claims abstract description 6
- TVXXNOYZHKPKGW-UHFFFAOYSA-N sodium molybdate (anhydrous) Chemical compound [Na+].[Na+].[O-][Mo]([O-])(=O)=O TVXXNOYZHKPKGW-UHFFFAOYSA-N 0.000 claims abstract description 6
- 230000002194 synthesizing effect Effects 0.000 claims abstract description 6
- 239000010955 niobium Substances 0.000 claims abstract description 4
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Natural products NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 3
- 239000002994 raw material Substances 0.000 claims abstract description 3
- 235000015393 sodium molybdate Nutrition 0.000 claims abstract description 3
- 238000001035 drying Methods 0.000 claims description 19
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 18
- 239000011259 mixed solution Substances 0.000 claims description 15
- 239000000243 solution Substances 0.000 claims description 14
- 238000006243 chemical reaction Methods 0.000 claims description 12
- 239000002244 precipitate Substances 0.000 claims description 11
- 239000012153 distilled water Substances 0.000 claims description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 10
- 230000008569 process Effects 0.000 claims description 8
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 7
- 235000006408 oxalic acid Nutrition 0.000 claims description 6
- 239000000843 powder Substances 0.000 claims description 6
- 238000004140 cleaning Methods 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 238000007664 blowing Methods 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 4
- 229910004619 Na2MoO4 Inorganic materials 0.000 claims description 3
- 238000003760 magnetic stirring Methods 0.000 claims description 3
- 238000005485 electric heating Methods 0.000 claims description 2
- 239000006228 supernatant Substances 0.000 claims description 2
- 238000005406 washing Methods 0.000 claims description 2
- 239000011248 coating agent Substances 0.000 claims 1
- 238000000576 coating method Methods 0.000 claims 1
- 238000001291 vacuum drying Methods 0.000 claims 1
- 230000003197 catalytic effect Effects 0.000 abstract description 28
- 230000000694 effects Effects 0.000 abstract description 9
- 230000005684 electric field Effects 0.000 abstract description 9
- 238000000926 separation method Methods 0.000 abstract description 7
- 238000007146 photocatalysis Methods 0.000 abstract description 3
- 230000001737 promoting effect Effects 0.000 abstract description 2
- 230000002195 synergetic effect Effects 0.000 abstract 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 23
- 239000001257 hydrogen Substances 0.000 description 23
- 229910052739 hydrogen Inorganic materials 0.000 description 23
- 238000004519 manufacturing process Methods 0.000 description 18
- 230000009471 action Effects 0.000 description 11
- 238000005286 illumination Methods 0.000 description 11
- 239000011941 photocatalyst Substances 0.000 description 7
- 239000004065 semiconductor Substances 0.000 description 6
- 239000013078 crystal Substances 0.000 description 5
- 230000004298 light response Effects 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- 238000000862 absorption spectrum Methods 0.000 description 4
- 239000002064 nanoplatelet Substances 0.000 description 4
- 238000000103 photoluminescence spectrum Methods 0.000 description 4
- 230000010287 polarization Effects 0.000 description 4
- 238000004626 scanning electron microscopy Methods 0.000 description 4
- 238000003917 TEM image Methods 0.000 description 3
- 239000003054 catalyst Substances 0.000 description 3
- 238000002173 high-resolution transmission electron microscopy Methods 0.000 description 3
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 3
- 230000006798 recombination Effects 0.000 description 3
- 238000005215 recombination Methods 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000006555 catalytic reaction Methods 0.000 description 2
- 239000002800 charge carrier Substances 0.000 description 2
- 239000003426 co-catalyst Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000004098 selected area electron diffraction Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000002371 ultraviolet--visible spectrum Methods 0.000 description 2
- 229910002621 H2PtCl6 Inorganic materials 0.000 description 1
- 229910003378 NaNbO3 Inorganic materials 0.000 description 1
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 1
- 230000032900 absorption of visible light Effects 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 229910052976 metal sulfide Inorganic materials 0.000 description 1
- 239000004005 microsphere Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000002715 modification method Methods 0.000 description 1
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 1
- 239000002055 nanoplate Substances 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000010899 nucleation Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000002957 persistent organic pollutant Substances 0.000 description 1
- 238000013033 photocatalytic degradation reaction Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000005036 potential barrier Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- MUPJWXCPTRQOKY-UHFFFAOYSA-N sodium;niobium(5+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Na+].[Nb+5] MUPJWXCPTRQOKY-UHFFFAOYSA-N 0.000 description 1
- 230000002269 spontaneous effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
Images
Classifications
-
- 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
- B01J27/047—Sulfides with chromium, molybdenum, tungsten or polonium
- B01J27/051—Molybdenum
-
- B01J35/33—
-
- B01J35/39—
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/03—Precipitation; Co-precipitation
- B01J37/031—Precipitation
-
- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/10—Heat treatment in the presence of water, e.g. steam
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- 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
- C01B3/042—Decomposition of water
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/02—Processes for making hydrogen or synthesis gas
- C01B2203/0266—Processes for making hydrogen or synthesis gas containing a decomposition step
- C01B2203/0277—Processes for making hydrogen or synthesis gas containing a decomposition step containing a catalytic decomposition step
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/10—Catalysts for performing the hydrogen forming reactions
- C01B2203/1041—Composition of the catalyst
-
- 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
MoS2Nanosheet-coated KNbO3A preparation method of a nanowire piezoelectric/photocatalytic material belongs to the field of photocatalysis. The invention uses niobium powder (Nb), potassium hydroxide (KOH) and sodium molybdate (Na)2MoO4·2H2O), thiourea (CN)2H4S) is taken as a raw material, and KNbO with good crystallinity is prepared by a simple two-step hydrothermal method3/MoS2The two-step hydrothermal method refers to the first hydrothermal reaction for synthesizing KNbO3Nanowire, and synthesizing KNbO by a second hydrothermal reaction3/MoS2Heterostructure piezoelectric/photocatalytic materials. The preparation method provided by the invention is simple, the experimental conditions are easy to control, the piezoelectric/ferroelectric characteristics are innovatively utilized, and the photocatalytic performance is optimized to the maximum extent by promoting the separation of photo-generated electrons and holes. The significantly improved catalytic performance is attributed to the synergistic effect of the heterostructure and the effect of the internal electric field induced by mechanical vibration to promote charge separation.
Description
Technical Field
The invention relates to a MoS2Nanosheet-coated KNbO3A preparation method of a nanowire heterostructure piezoelectric/photocatalytic material belongs to the technical field of photocatalytic material preparation.
Background
Semiconductor photocatalysis technology such as photocatalytic hydrogen production and photocatalytic degradation of organic pollutants is a method with great prospect for solving the world energy crisis and the environmental crisis. A number of semiconductor photocatalysts including metal oxides, metal sulfides, perovskite metal oxides, and the like have been widely explored. However, the recombination of photogenerated electrons and holes greatly limits the improvement of photocatalytic performance. To address this problem, many modification methods such as doping, co-catalyst loading, nanostructure design, etc. have been extensively studied. However, the photocatalytic performance of semiconductor photocatalysts is still unsatisfactory. Therefore, there is a need for a method that effectively facilitates the separation of photogenerated electrons and holes.
More recently, the development of new and more recently developed devicesThe research shows that the internal electric field induced by the piezoelectric/ferroelectric material can effectively improve the photocatalytic performance. The piezoelectric/ferroelectric material has a piezoelectric/ferroelectric effect, and when an external force acts, an internal electric field is generated and serves as a driving force to promote separation and transfer of photo-generated electrons and holes, so that the photocatalytic performance is improved. Various types of piezoelectric/ferroelectric materials have been used in the field of photocatalysis, such as ZnO, CdS, NaNbO3、BaTiO3And MoS2And the like. However, almost all single piezoelectric/ferroelectric materials have wide forbidden bands and can only absorb ultraviolet light, which greatly limits the improvement of catalytic activity. The literature shows that the utilization rate of sunlight can be effectively improved by constructing a heterostructure photocatalyst by compounding a piezoelectric/ferroelectric material with a narrow band gap semiconductor.
KNbO3The ferroelectric perovskite oxide is a typical ferroelectric perovskite oxide, an internal electric field is generated through spontaneous polarization, and the size of the internal electric field is changed through a piezoelectric effect when an external force acts on the ferroelectric perovskite oxide. Furthermore, KNbO3Has proper energy band position and excellent chemical stability, thereby attracting the attention of researchers. Due to MoS2Has an asymmetric crystal structure and has single-layer or multi-layer MoS under the action of external force2The nanosheet has piezoelectric response, and the establishment of an internal electric field drives the separation and transfer of photoproduction electrons and holes, so that the photocatalytic performance is hopeful to be improved. Furthermore, MoS2The nano sheet has excellent visible light response and a large number of active edge positions, can play a role of a co-catalyst, transfers photoproduction electrons and holes, and reduces a potential barrier. The piezoelectric/ferroelectric material with one-dimensional and two-dimensional nano structures is easy to deform and is easy to generate piezoelectric potential under the action of external force. In addition, the ultrasonic cavitation effect of the ultrasonic wave can generate huge stress, and the experimental process is simple and easy to implement, so that the ultrasonic wave is adopted as an external force source.
Hitherto, KNbO3/MoS2The piezoelectric/photocatalytic hydrogen production performance of (2) has not been reported.
Disclosure of Invention
The invention aims to promote the separation of photogenerated electrons and holes in a photocatalyst and combine the semiconductor property of a piezoelectric/ferroelectric material with piezoelectric/ferroelectric polarization to provide a photocatalystMoS2Nanosheet-coated KNbO3A preparation method of a nanowire heterostructure piezoelectric/photocatalytic material.
MoS2Nanosheet-coated KNbO3The preparation method of the nanowire piezoelectric/photocatalytic material is characterized in that niobium powder (Nb), potassium hydroxide (KOH) and sodium molybdate (Na)2MoO4·2H2O), thiourea (CN)2H4S) is taken as a raw material, and KNbO with good crystallinity is prepared by a simple two-step hydrothermal method3/MoS2The two-step hydrothermal method refers to the first hydrothermal reaction for synthesizing KNbO3Nanowire, and synthesizing KNbO by a second hydrothermal reaction3/MoS2Heterostructure piezoelectric/photocatalytic materials.
Further, the preparation method specifically comprises the following steps:
(1) first step hydrothermal synthesis of KNbO3The specific process of the nanowire is as follows:
firstly, distilled water and KOH are prepared into KOH solution with the concentration of 13mol/L, then metal niobium powder is added, the ratio of the metal niobium powder to the KOH in the solution is 7.5 to 8.5 weight percent, and the mixture is magnetically stirred for 0.5 to 1.5 hours; finally transferring the mixed solution into a reaction kettle, and adjusting the temperature of the electric heating air blast drying box to 140-160 ℃ for 10-14 h; after the reaction is finished and the temperature is cooled to the room temperature, repeatedly cleaning the white precipitate by using distilled water and alcohol, and drying the white precipitate in a drying box to obtain KNbO3A nanowire;
(2) second step hydrothermal synthesis of KNbO3/MoS2The heterostructure piezoelectric/photocatalytic material comprises the following specific processes:
first, Na is added2MoO4·2H2O and CN2H4S is dissolved in oxalic acid solution, Na2MoO4·2H2O and CN2H4The ratio of S is 1:2, and the mixture is magnetically stirred for 25-35min to form a uniformly mixed solution; subsequently, the synthesized KNbO is subjected to3Placing the nanowire in the mixed solution, KNbO3The mass concentration of the nano-wire in the mixed solution is 0.35-0.45g/L, and the magnetic stirring is carried out for 0.5-1.5 h; finally, theTransferring the mixed solution into a reaction kettle, and adjusting the temperature of an electrothermal blowing drying box to 180-220 ℃ for 22-26 h; after the reaction is finished and the temperature is cooled to the room temperature, repeatedly washing the precipitate by using distilled water and alcohol, and drying to obtain KNbO3/MoS2And (3) powder.
Further, in the step (1), in the white precipitate cleaning process, firstly, cleaning with distilled water, and then cleaning with alcohol until the pH value of the supernatant is 7; the drying temperature of the wet powder is 60 ℃, and the drying time is 12 h.
Further, in the step (2), the concentration of the oxalic acid solution is 0.075 mol/L; the drying environment of the wet powder is vacuum, the drying temperature is 60 ℃, and the drying time is 12 h.
As a general inventive concept, the invention also provides the MoS2Nanosheet-coated KNbO3A method for producing hydrogen by catalysis of a nanowire heterostructure.
Before hydrogen production test, 0.2g/L of catalyst suspension and 0.2mmol of H2PtCl6·6H2The O solution was irradiated with a Xe lamp of 300W for 180min to form a platinum (Pt) -supported catalyst, and then a powder sample was collected. The piezoelectric/photocatalytic hydrogen production test is carried out in a closed gas circulation system. The method specifically comprises the following steps: 20mg of Pt-supported photocatalyst was dispersed in 100mL of a solution containing 15 vol.% triethanolamine (sacrificial agent), and hydrogen production was measured with a gas chromatograph (Techcomp GC-7900) using a 300W Xe lamp as a simulated solar light source and an ultrasonic cleaner to provide periodic local mechanical stress.
The working principle of the invention is as follows:
in the preparation of KNbO3/MoS2In the heterostructure photocatalyst, KNbO3Nanowire and MoS2The nano sheets have large specific surface area and have piezoelectric/ferroelectric effect. Furthermore, MoS2Has better visible light response and promotes the absorption of visible light of the material.
To KNbO3/MoS2KNbO after the heterostructure photocatalyst is applied with external mechanical force3An internal electric field is generated due to ferroelectric polarization, so that the energy band is bent. Of a single or several layersMoS2The nano-sheet has the characteristic of easy deformation, and can generate a piezoelectric potential under the action of external force, thereby promoting the separation and transfer of photoproduction electrons and holes, reducing the recombination rate of electron holes and improving the catalytic performance.
The invention has the beneficial technical effects that:
(1)KNbO3nanowire and MoS2The nano sheets have larger specific surface area and can provide more reactive active sites for catalytic reaction;
(2)MoS2the material has better visible light response, and the visible light response of the material is promoted;
(3)KNbO3nanowire and MoS2The nano-sheets have piezoelectric/ferroelectric effect and can generate an internal electric field under the action of huge mechanical external force;
(4) an internal electric field generated by piezoelectric/ferroelectric polarization can effectively separate photo-generated electron-hole pairs and improve the catalytic performance.
Drawings
FIG. 1(a) shows KNbO3Scanning Electron microscopy of nanowires, FIG. 1(b) is KNbO3/MoS2Scanning electron micrograph of heterostructure catalytic material, FIG. 1(c) is MoS2Scanning electron microscopy of the nanoplatelets.
FIG. 2(a) shows KNbO3/MoS2Low resolution TEM image of heterostructure catalytic material, KNbO in FIG. 2(b)3/MoS2High resolution TEM image of heterostructure catalytic material, KNbO in FIG. 2(c)3/MoS2Selected area electron diffraction patterns of heterostructure catalytic materials.
FIG. 3(a) shows KNbO3Ultraviolet-visible absorption spectrum of the nanowires, KNbO in FIG. 3(b)3/MoS2UV-visible absorption spectra of heterostructure catalytic materials, FIG. 3(c) is MoS2Uv-vis absorption spectra of the nanoplatelets.
FIG. 4(a) shows KNbO3Photoluminescence spectrum of nanowire, KNbO in FIG. 4(b)3/MoS2Photoluminescence spectra of the heterostructure catalytic materials.
FIG. 5(a) shows KNbO3Nanowire in simulation of sunlightThe catalytic hydrogen production performance under the irradiation is shown in FIG. 5(b) as KNbO3/MoS2The catalytic hydrogen production performance of the heterostructure catalytic material under simulated solar illumination is shown in FIG. 5(c) as MoS2The hydrogen production performance of the nanosheet under simulated solar illumination is shown in FIG. 5(d) as KNbO3The catalytic hydrogen production performance of the nano-wire under the combined action of simulated solar illumination and ultrasonic waves is shown in FIG. 5(e) as KNbO3/MoS2The catalytic hydrogen production performance of the heterostructure catalytic material under the combined action of simulated solar illumination and ultrasonic waves is shown in FIG. 5(f) as MoS2The hydrogen production performance of the nanosheet is catalyzed under the combined action of simulated solar illumination and ultrasonic waves.
Detailed Description
The invention is intended to cover alternatives, modifications, equivalents and alternatives which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, certain specific details are set forth in order to provide a better understanding of the present invention. It will be apparent to one skilled in the art that the present invention may be practiced without these specific details.
Preparation of KNbO3/MoS2Heterostructure photocatalytic material:
(1) first step hydrothermal synthesis of KNbO3The specific process of the nanowire is as follows:
firstly, 10.942g of KOH is dissolved in 15ml of distilled water to prepare a KOH solution with the concentration of 13 mol/L; 0.874g of metal Nb powder is added into the alkaline solution, and magnetic stirring is carried out for 1 hour; and finally, transferring the mixed solution into a 50mL reaction kettle, and adjusting the temperature of an electrothermal blowing drying oven to 150 ℃ for 12 hours. After the reaction was completed and cooled to room temperature, the white precipitate was repeatedly washed with distilled water and alcohol to pH 7, and dried in a drying oven at 60 ℃ for 12 hours.
(2) Second step hydrothermal synthesis of KNbO3/MoS2The heterostructure piezoelectric/photocatalytic material comprises the following specific processes:
first, 64.8mg of Na is added2MoO4·2H2O and 129.6mg of CN2H4S is dissolved in the oxalic acid solution,magnetically stirring for 30min to form a uniformly mixed solution; subsequently, 100mg of KNbO was synthesized3Placing the nanowires in the solution, and magnetically stirring for 1 h; finally, the mixed solution was transferred to a 50mL reaction vessel, and the temperature of the electrothermal blowing dry box was adjusted to 200 ℃ for 24 hours. After the reaction was completed and cooled to room temperature, the precipitate was repeatedly washed with distilled water and alcohol to pH 7, and the white precipitate was dried in a vacuum oven at 60 ℃ for 12 hours.
The practical effect of the invention is proved by experiments.
FIG. 1(a) shows KNbO3Scanning Electron microscopy of nanowires, FIG. 1(b) is KNbO3/MoS2Scanning electron micrograph of heterostructure catalytic material, FIG. 1(c) is MoS2Scanning electron microscopy of the nanoplatelets. KNbO as shown in FIG. 1(a)3Mainly has the shape of a nanowire, and a few of the nanowires are in a tower shape with the micron scale, the width of the nanowire is about 120-400nm, the length of the nanowire is 2-7 mu m, and the maximum length-diameter ratio reaches 60. Furthermore, KNbO3Has a smooth surface and is occasionally stepped, which is KNbO3Generated during nucleation growth. KNbO3/MoS2As shown in FIG. 1(b), MoS2The nano-sheet uniformly grows on KNbO3Of (2) is provided. FIG. 1(c) is pure MoS2Nanosheet microspheres having a diameter of about 2.8 μm and a nanosheet layer thickness of about 20 nm.
FIG. 2(a) shows KNbO3/MoS2Low resolution TEM image of heterostructure catalytic material, KNbO in FIG. 2(b)3/MoS2High resolution TEM image of heterostructure catalytic material, KNbO in FIG. 2(c)3/MoS2Selected area electron diffraction patterns of heterostructure catalytic materials. A low-resolution TEM image of the sample is shown in FIG. 2(a), MoS2The nanosheets uniformly grown on KNbO3The surface of the nanowire. The selected area electron diffractogram is shown in FIG. 2(c), and clear diffraction spots indicate KNbO3Nature of single crystal, MoS2Two blurred diffraction rings, corresponding to MoS, are generated due to the stacking of a large number of nanoplates2The (100) and (110) crystal planes of the nanosheets. High resolution TEM of the sample As shown in FIG. 1(b), 0.404nm and 0.399nm correspond to KNbO, respectively3(110) and (001) crystal faces of (1), and KNbO3Nanowire along [110 ]]And (4) directionally growing. Lattice spacing of 0.660nm corresponds to MoS2(002) crystal face of (a).
FIG. 3(a) shows KNbO3Ultraviolet-visible absorption spectrum of the nanowires, KNbO in FIG. 3(b)3/MoS2UV-visible absorption spectra of heterostructure catalytic materials, FIG. 3(c) is MoS2Uv-vis absorption spectra of the nanoplatelets. Pure KNbO3The ultraviolet light part with the main absorption wavelength less than 410nm and the absorption edge of 418nm, and pure MoS2Has excellent visible light response besides absorbing ultraviolet light. For KNbO3/MoS2The light absorption range is widened to the visible light region, which shows that the narrow-band-gap semiconductor MoS is loaded2The photoresponse range of the material can be widened.
FIG. 4(a) shows KNbO3Photoluminescence spectrum of nanowire, KNbO in FIG. 4(b)3/MoS2Photoluminescence spectra of the heterostructure catalytic materials. With KNbO3Compared with KNbO3/MoS2Has lower peak intensity, indicating KNbO3/MoS2The transfer of charge carriers is facilitated and the recombination of photogenerated charge carriers is reduced.
FIG. 5(a) shows KNbO3The catalytic hydrogen production performance of the nano-wire under the simulated solar illumination is shown in FIG. 5(b) as KNbO3/MoS2The catalytic hydrogen production performance of the heterostructure catalytic material under simulated solar illumination is shown in FIG. 5(c) as MoS2The hydrogen production performance of the nanosheet under simulated solar illumination is shown in FIG. 5(d) as KNbO3The catalytic hydrogen production performance of the nano-wire under the combined action of simulated solar illumination and ultrasonic waves is shown in FIG. 5(e) as KNbO3/MoS2The catalytic hydrogen production performance of the heterostructure catalytic material under the combined action of simulated solar illumination and ultrasonic waves is shown in FIG. 5(f) as MoS2The hydrogen production performance of the nanosheet is catalyzed under the combined action of simulated solar illumination and ultrasonic waves. Under the irradiation of simulated sunlight, KNbO3/MoS2The hydrogen yield (305 mu mol/g) of the catalyst is obviously higher than that of KNbO3And MoS2The amount of hydrogen produced. Under the combined action of simulated sunlight and ultrasonic waves, the hydrogen generation amount of all samples is remarkably improved.KNbO3/MoS2The hydrogen generation rate of (2) reaches 573 mu mol/g, which is about 1.9 times that of the simulated sunlight. The results show that the ultrasonic vibration has obvious promotion effect on the hydrogen generation.
Claims (6)
1. MoS2Nanosheet-coated KNbO3The preparation method of the nanowire piezoelectric/photocatalytic material is characterized in that niobium powder (Nb), potassium hydroxide (KOH) and sodium molybdate (Na)2MoO4·2H2O), thiourea (CN)2H4S) is taken as a raw material, and KNbO with good crystallinity is prepared by a simple two-step hydrothermal method3/MoS2Heterostructure piezoelectric/photocatalytic material, wherein MoS2The nanosheets uniformly grown on KNbO3Forming a coating structure on the surface of the nanowire;
the two-step hydrothermal method refers to the first hydrothermal reaction for synthesizing KNbO3Nanowire, and synthesizing KNbO by a second hydrothermal reaction3/MoS2A heterostructure piezoelectric/photocatalytic material comprising first Na2MoO4·2H2O and CN2H4S is dissolved in oxalic acid solution to form a uniformly mixed solution, and then the synthesized KNbO is mixed3The nanowires are placed in the above mixed solution.
2. The MoS of claim 12Nanosheet-coated KNbO3The preparation method of the nanowire piezoelectric/photocatalytic material is characterized by comprising the following steps of:
(1) first step hydrothermal synthesis of KNbO3The specific process of the nanowire is as follows:
firstly, distilled water and KOH are prepared into KOH solution with the concentration of 13mol/L, then metal niobium powder is added, the ratio of the metal niobium powder to the KOH in the solution is 7.5 to 8.5 weight percent, and the mixture is magnetically stirred for 0.5 to 1.5 hours; finally transferring the mixed solution into a reaction kettle, and adjusting the temperature of the electric heating air blast drying box to 140-160 ℃ for 10-14 h; after the reaction is finished and the temperature is cooled to the room temperature, repeatedly cleaning the white precipitate by using distilled water and alcohol, and drying the white precipitate in a drying box to obtain KNbO3A nanowire;
(2) second step hydrothermal synthesis of KNbO3/MoS2The heterostructure piezoelectric/photocatalytic material comprises the following specific processes:
first, Na is added2MoO4·2H2O and CN2H4S is dissolved in oxalic acid solution, Na2MoO4·2H2O and CN2H4The ratio of S is 1:2, and the mixture is magnetically stirred for 25-35min to form a uniformly mixed solution; subsequently, the synthesized KNbO is subjected to3Placing the nanowire in the mixed solution, KNbO3The mass concentration of the nano-wire in the mixed solution is 4.5-5.5g/L, and the magnetic stirring is carried out for 0.5-1.5 h; finally, transferring the mixed solution into a reaction kettle, and adjusting the temperature of an electrothermal blowing drying box to 180-220 ℃ for 22-26 h; after the reaction is finished and the temperature is cooled to the room temperature, repeatedly washing the precipitate by using distilled water and alcohol, and drying to obtain KNbO3/MoS2And (3) powder.
3. MoS according to claim 22Nanosheet-coated KNbO3The preparation method of the nanowire piezoelectric/photocatalytic material is characterized in that in the step (1), the white precipitate is cleaned until the pH value of supernatant is 7.
4. MoS according to claim 22Nanosheet-coated KNbO3The preparation method of the nanowire piezoelectric/photocatalytic material is characterized in that in the step (1), the drying condition is 60 ℃ and 12 hours.
5. MoS according to claim 22Nanosheet-coated KNbO3The preparation method of the nanowire piezoelectric/photocatalytic material is characterized in that in the step (2), the concentration of the oxalic acid solution is 0.075 mol/L.
6. MoS according to claim 22Nanosheet-coated KNbO3The preparation method of the nanowire piezoelectric/photocatalytic material is characterized in that in the step (2), the drying conditions are as follows: vacuum drying at 60 deg.C for 12 hr.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910063881.4A CN109647445B (en) | 2019-01-23 | 2019-01-23 | MoS2Nanosheet-coated KNbO3Preparation method of nanowire piezoelectric/photocatalytic material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910063881.4A CN109647445B (en) | 2019-01-23 | 2019-01-23 | MoS2Nanosheet-coated KNbO3Preparation method of nanowire piezoelectric/photocatalytic material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109647445A CN109647445A (en) | 2019-04-19 |
| CN109647445B true CN109647445B (en) | 2020-08-25 |
Family
ID=66120505
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910063881.4A Active CN109647445B (en) | 2019-01-23 | 2019-01-23 | MoS2Nanosheet-coated KNbO3Preparation method of nanowire piezoelectric/photocatalytic material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109647445B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110773201B (en) * | 2019-05-28 | 2020-10-09 | 江南大学 | Spherical molybdenum disulfide/copper sulfide nanocomposite and preparation method thereof |
| CN110420652B (en) * | 2019-08-14 | 2022-04-12 | 哈尔滨工业大学 | NaYF4:Yb/Er@MoS2Core-shell structure micron crystal and preparation method thereof |
| CN111468133B (en) * | 2020-05-29 | 2022-12-27 | 陕西科技大学 | Preparation method of potassium niobate/alpha-ferric oxide heterogeneous photocatalyst |
| CN111558384A (en) * | 2020-06-01 | 2020-08-21 | 南昌航空大学 | 2D/2D heterojunction piezoelectric-photocatalyst and preparation method thereof |
| CN112898019B (en) * | 2021-01-28 | 2023-04-18 | 金宏气体股份有限公司 | p-n-KNbO 3 /Cu 2 S heterojunction piezoelectric ceramic, preparation method thereof and application of S heterojunction piezoelectric ceramic in self-powered efficient hydrogen production |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107185558B (en) * | 2017-05-16 | 2019-09-03 | 浙江师范大学 | A kind of photocatalysis hydrogen production catalyst and preparation method thereof |
| CN107362792B (en) * | 2017-06-22 | 2020-02-21 | 江苏大学 | Preparation method of strontium titanate/tin niobate composite nano material |
-
2019
- 2019-01-23 CN CN201910063881.4A patent/CN109647445B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN109647445A (en) | 2019-04-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109647445B (en) | MoS2Nanosheet-coated KNbO3Preparation method of nanowire piezoelectric/photocatalytic material | |
| CN109794268B (en) | MoSe2Nanosheet-coated KNbO3Preparation method of nano-wire heterostructure photocatalytic material | |
| CN111437867B (en) | Composite photocatalyst containing tungsten oxide and preparation method and application thereof | |
| CN106362774B (en) | A kind of 1D/2D vertical configuration CdS/MoS2Produce the preparation method of hydrogen catalyst | |
| CN106378160B (en) | It is a kind of to prepare CdS/MoS2The method of composite hollow square photochemical catalyst | |
| CN113145138B (en) | Thermal response type composite photocatalyst and preparation method and application thereof | |
| CN112774696B (en) | Heterostructure catalyst for decomposing water to produce hydrogen by utilizing solar energy and preparation method | |
| CN113649075B (en) | Balsam pear-like NaNbO 3 Preparation method of @ ZIF-8 piezoelectric-photocatalyst | |
| CN114588888A (en) | Photocatalyst and preparation method and application thereof | |
| CN107890861B (en) | Preparation method of titanium dioxide lamella/graphene composite film with {001} crystal face | |
| CN110252352A (en) | A kind of carbon quantum dot modification bismuth tungstate/ordered big hole fluorine-doped tin oxide composite photo-catalyst and its preparation method and application | |
| CN110961133A (en) | Nonmetal BCN/g-C3N4Van der Waals heterojunction photocatalyst and preparation method and application thereof | |
| CN111841530A (en) | Catalyst for promoting water photolysis to produce hydrogen and preparation method thereof | |
| CN109569562A (en) | A kind of preparation method of zinc oxide titanium composite nano powder | |
| CN109046391A (en) | A kind of composite material and preparation method and the application in visible photocatalysis aquatic products hydrogen | |
| CN110404546B (en) | A kind of Ni (OH) 2 Nanoparticle modified SrTiO 3 Composite catalyst and preparation method and application thereof | |
| CN110627116B (en) | Hydrogen-doped TiO (titanium dioxide)2Phase-change nano material and application thereof | |
| CN108543540B (en) | Cerium fluoride/attapulgite up-conversion composite photocatalytic material and preparation method and application thereof | |
| CN114292641B (en) | Preparation method of indium zinc sulfide quantum dot | |
| CN113877556B (en) | Indium oxyhydroxide/modified attapulgite photocatalytic composite material and preparation method and application thereof | |
| CN109078636B (en) | Plasma photocatalyst, preparation method thereof and application thereof in hydrogen production | |
| CN112517029A (en) | Composite photocatalyst rich in S vacancy as well as preparation method and application thereof | |
| CN107376942B (en) | Spherical Bi2S3Preparation method of photocatalytic material | |
| CN111495391A (en) | Composite photocatalyst and preparation method and application thereof | |
| CN113385167A (en) | Preparation method of stannic oxide nanosheet loaded cubic sodium tantalate |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |