Novel photocatalyst for producing hydrogen from organic matter wastewater and preparation method of novel photocatalyst

Abstract

The invention discloses a novel photocatalyst for producing hydrogen from organic matter wastewater and a preparation method of the novel photocatalyst, and relates to the technical field of photocatalysis. The photocatalyst disclosed by the invention is combined with oxidation-reduction capability, and can effectively degrade and produce hydrogen under the irradiation of sunlight. Through combination of quaternized porous tungsten oxide and vanadate radicals, silver vanadate load growth is promoted, the sunlight utilization rate is increased, and the electron-hole recombination rate is reduced. Reduced graphene oxide is used for pretreatment, active groups are introduced, the reduced graphene oxide is compounded with tungsten oxide / silver vanadate, the binding force is enhanced through heat treatment, photo-induced electron-hole pair compounding is inhibited through the conductivity, and the visible light catalytic performance is improved. The adsorption effect of porous tungsten trioxide and reduced graphene oxide can accelerate the degradation of organic matters. By optimizing the proportion of silver vanadate, tungsten oxide and reduced graphene oxide, the visible light response and charge separation efficiency are enhanced, the degradation and hydrogen production performance is improved, and light corrosion is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of photocatalysis, and in particular to a novel photocatalyst for producing hydrogen from organic wastewater and a preparation method thereof. Background Art

[0002] Since the discovery in 1972 that TiO2 can decompose water into hydrogen and oxygen under ultraviolet light, research on semiconductor-catalyzed water splitting has garnered widespread attention. Storing energy in the form of hydrogen is much more convenient than storing electrical or thermal energy. Furthermore, hydrogen has numerous advantages, including a high calorific value (≈143 kJ / g), clean and environmentally friendly properties, and non-toxicity.

[0003] However, the most strongly distributed components in the solar spectrum are concentrated in the visible light region. Therefore, designing catalysts with high quantum yields in the visible light region is the key to fully utilizing solar energy and reducing the cost of photocatalytic hydrogen production.

[0004] In recent years, scientists have explored the possibility of using wastewater containing toxic organic pollutants as sacrificial agents in photocatalytic hydrogen production systems, thereby establishing bifunctional photocatalytic systems. This approach, combined with a series of studies, suggests that bifunctional photocatalytic systems could utilize toxic organic pollutants as sacrificial agents for photocatalytic water splitting to produce hydrogen. This approach reduces the cost of sacrificial agents while simultaneously degrading organic pollutants, achieving two goals at once. This represents a promising photocatalytic system for research and development. Summary of the Invention

[0005] The purpose of the present invention is to provide a novel photocatalyst for producing hydrogen from organic wastewater and a preparation method thereof, so as to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solution: a method for preparing a new photocatalyst for producing hydrogen from organic wastewater, comprising the following preparation steps: (1) Add 40-60 mL of water and quaternized tungsten trioxide powder to the sodium vanadate solution, stir for 4-8 hours, filter out the solid, wash, dry, and calcine to obtain V2O5 / tungsten trioxide; (2) Add V2O5 / tungsten trioxide to the silver ammonia solution, stir for 4-6 hours, filter out the solid, wash, and dry to obtain silver vanadate / tungsten oxide; (3) Mix the hydroxylated reduced graphene oxide and the solvent to prepare a 35-55 wt% mixed solution, add silver vanadate / tungsten oxide, grind at 200-500 r / s for 100-180 min, filter and collect the solid, dry at 100 °C for 6 h, and heat to 500 °C for calcination for 5 h.

[0007] Furthermore, the quaternized tungsten trioxide powder is prepared by quaternizing and modifying tungsten trioxide porous nanorods as raw materials; the tungsten trioxide porous nanorods are prepared with reference to CN201711479360.4.

[0008] Furthermore, the sodium vanadate solution in step (1) is prepared from vanadium pentoxide and sodium hydroxide.

[0009] Furthermore, in step (1), the mass ratio of the quaternized tungsten trioxide powder to the vanadium pentoxide is 1-5:1.

[0010] Furthermore, the drying temperature in step (1) is 100°C.

[0011] Furthermore, in step (1), the calcination temperature is 300-400° C., and the calcination time is 5 h.

[0012] Furthermore, the drying temperature in step (2) is 100-105°C.

[0013] Furthermore, the hydroxylated reduced graphene oxide in step (3) is prepared from reduced graphene oxide, aminobenzoic acid, and isoamyl nitrite.

[0014] Furthermore, in step (3), the mass ratio of the silver vanadate / tungsten oxide to the hydroxylated reduced graphene oxide is 1-10:1-10.

[0015] Furthermore, the solvent in step (3) includes one or more of xylene, propylene glycol methyl ether, propylene carbonate, methyl isobutyl ketone and ethylene glycol ethyl ether.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The photocatalyst of the present invention has both oxidation and reduction capabilities, and can simultaneously achieve efficient degradation and hydrogen production under sunlight.

[0017] (2) The present invention utilizes quaternized porous tungsten oxide to attract vanadate to bind, thereby facilitating the growth of surface silver vanadate loading, achieving the composite of silver vanadate and tungsten oxide, and to a certain extent improving the utilization rate of sunlight, reducing the recombination rate of photogenerated electrons and holes, and maximizing the redox capacity.

[0018] (3) The present invention pre-treats graphene oxide by reducing it so that its surface carries active groups such as hydroxyl and carboxyl groups. During the grinding and compounding process with tungsten oxide / silver vanadate, the bonding strength is strengthened by subsequent heat treatment. The reduced graphene oxide has good conductivity and can act as an electron "high-speed channel" to effectively inhibit the recombination of photogenerated electron-hole pairs in WO3, thereby improving the visible light catalytic performance. In addition, porous tungsten trioxide and reduced graphite oxide have an adsorption effect and can adsorb organic matter in wastewater, thereby locally concentrating it and accelerating degradation. The present invention can significantly enhance the visible light response and charge separation efficiency by designing the ratio of silver vanadate, tungsten oxide, and reduced graphene oxide, thereby achieving a synergistic effect, thereby improving the degradation of organic pollutants and photocatalytic hydrogen production performance, while reducing photocorrosion dissolution. DETAILED DESCRIPTION

[0019] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0020] Example 1; (1) Weigh 0.1 g of tungsten trioxide porous nanorods, disperse them in 30 mL of anhydrous ethanol, add 10 mL of 0.025 g / mL 3-aminopropanetriethoxysilane ethanol solution dropwise, react for 5 h, and vacuum dry at 45 ° C for 12 h to obtain pretreated tungsten trioxide powder; (2) Add the pretreated tungsten trioxide powder to water with a mass of 4 times that of the pretreated tungsten trioxide powder, adjust the pH to 9 with alkali solution, stir and heat to 55℃, control the pH to 9, and add 3-chloro-2-hydroxypropyltrimethylammonium chloride while stirring. The mass ratio of pretreated tungsten trioxide powder and 3-chloro-2-hydroxypropyltrimethylammonium chloride is 1:0.1. After adding, continue stirring and heat for 1 hour, adjust the pH to 6.5, filter and take the solid, wash with water 5 times, and dry at 80℃ for 12h to obtain quaternized tungsten trioxide powder; (3) Add 5 g of vanadium pentoxide to 25 mL of 1 mol / L sodium hydroxide solution and stir for 20 min to generate sodium vanadate solution; (4) Add 40 mL of water and quaternized tungsten trioxide powder to the sodium vanadate solution. The mass ratio of quaternized tungsten trioxide powder to vanadium pentoxide is 1:1. Stir at 100 rpm for 4 to 8 hours. Filter the solid, wash it with distilled water three times, dry it at 100 ° C for 6 hours, and heat it to 300 ° C for calcination for 5 hours to obtain V2O5 / tungsten trioxide. (5) Weigh 1 mmol of silver nitrate to prepare a 10 mmol / L solution. Add 9.5 wt% ammonia water dropwise to the solution while shaking until precipitation is complete. After solid-liquid separation, discard the supernatant and continue to add 9.5 wt% ammonia water dropwise to the solid until the initial precipitate is completely dissolved, thereby obtaining a silver ammonia solution. (6) Add V2O5 / tungsten trioxide to the silver ammonia solution, stir for 4 hours, filter out the solid, wash it with distilled water three times, and dry it at 100℃ for 12 hours to obtain silver vanadate / tungsten oxide; (7) At room temperature, 600 mg of graphite oxide was dispersed in 600 mL of water, and then 1.5 g of sodium dodecylbenzenesulfonate was added. After ultrasonic treatment for 2 h, a graphite oxide dispersion with a concentration of 1 mg / mL was obtained. Then, 3 mL of hydrazine hydrate was added to the above graphite oxide dispersion, and the mixture was heated to 100 °C in an oil bath. After reacting for 14 h, a black reduced graphene oxide suspension was obtained. (8) Lower the oil bath reaction temperature to 80°C, add 7.31 g of aminobenzoic acid and 3.15 g of isoamyl nitrite to the reduced graphene oxide suspension in sequence, and react in the oil bath for 10 h to obtain a hydroxyl-modified reduced graphene oxide dispersion. Centrifuge and separate the solid, and dry it at 80°C for 10 h to obtain hydroxylated reduced graphene oxide. (9) Mix the hydroxylated reduced graphene oxide and xylene to form a 35 wt% mixed solution, add silver vanadate / tungsten oxide, and the mass ratio of silver vanadate / tungsten oxide to hydroxylated reduced graphene oxide is 1:1. Grind at 200 r / s for 100 min, filter and collect the solid, dry at 100 °C for 6 h, and heat to 500 °C for calcination for 5 h.

[0021] Example 2; (1) Weigh 3.8 g of tungsten trioxide porous nanorods, disperse them in 30 mL of anhydrous ethanol, add 20 mL of 0.025 g / mL 3-aminopropanetriethoxysilane ethanol solution dropwise, react for 5 h, and vacuum dry at 45 ° C for 12 h to obtain pretreated tungsten trioxide powder; (2) Add the pretreated tungsten trioxide powder to water with a mass of 4 times that of the pretreated tungsten trioxide powder, adjust the pH to 9 with alkali solution, stir and heat to 55℃, control the pH to 9, and add 3-chloro-2-hydroxypropyltrimethylammonium chloride while stirring. The mass ratio of pretreated tungsten trioxide powder and 3-chloro-2-hydroxypropyltrimethylammonium chloride is 1:0.1. After adding, continue stirring and heat for 1 hour, adjust the pH to 6.5, filter and take the solid, wash with water 5 times, and dry at 80℃ for 12h to obtain quaternized tungsten trioxide powder; (3) Add 5 g of vanadium pentoxide to 25 mL of 1 mol / L sodium hydroxide solution and stir for 20 min to generate sodium vanadate solution; (4) Add 40 mL of water and quaternized tungsten trioxide powder to the sodium vanadate solution. The mass ratio of quaternized tungsten trioxide powder to vanadium pentoxide is 5:1. Stir at 100 rpm for 4 hours. Filter the solid, wash it with distilled water three times, dry it at 100 ° C for 6 hours, and heat it to 300 ° C for calcination for 5 hours to obtain V2O5 / tungsten trioxide. (5) Weigh 1 mmol of silver nitrate to prepare a 10 mmol / L solution. Add 9.5 wt% ammonia water dropwise to the solution while shaking until precipitation is complete. After solid-liquid separation, discard the supernatant and continue to add 9.5 wt% ammonia water dropwise to the solid until the initial precipitate is completely dissolved, thereby obtaining a silver ammonia solution. (6) Add V2O5 / tungsten trioxide to the silver ammonia solution, stir for 4 hours, filter out the solid, wash it with distilled water three times, and dry it at 100℃ for 12 hours to obtain silver vanadate / tungsten oxide; (7) At room temperature, 600 mg of graphite oxide was dispersed in 600 mL of water, and then 1.5 g of sodium dodecylbenzenesulfonate was added. After ultrasonic treatment for 2 h, a graphite oxide dispersion with a concentration of 1 mg / mL was obtained. Then, 3 mL of hydrazine hydrate was added to the above graphite oxide dispersion, and the mixture was heated to 100 °C in an oil bath. After reacting for 14 h, a black reduced graphene oxide suspension was obtained. (8) Lower the oil bath reaction temperature to 80°C, add 7.31 g of aminobenzoic acid and 3.15 g of isoamyl nitrite to the reduced graphene oxide suspension in sequence, and react in the oil bath for 10 h to obtain a hydroxyl-modified reduced graphene oxide dispersion. Centrifuge and separate the solid, and dry it at 80°C for 10 h to obtain hydroxylated reduced graphene oxide. (9) Mix hydroxylated reduced graphene oxide and propylene glycol methyl ether to form a 35 wt% mixed solution, add silver vanadate / tungsten oxide, and the mass ratio of silver vanadate / tungsten oxide to hydroxylated reduced graphene oxide is 10:1. Grind at 200 r / s for 100 min, filter and collect the solid, dry at 100 °C for 6 h, and heat to 500 °C for calcination for 5 h.

[0022] Example 3; (1) Weigh 6 g of tungsten trioxide porous nanorods, disperse them in 30 mL of anhydrous ethanol, add 20 mL of 0.025 g / mL 3-aminopropanetriethoxysilane ethanol solution dropwise, react for 5 h, and vacuum dry at 45 ° C for 12 h to obtain pretreated tungsten trioxide powder; (2) Add the pretreated tungsten trioxide powder to water with a mass of 4-6 times that of the pretreated tungsten trioxide powder, adjust the pH to 9 with alkali solution, stir and heat to 55℃, control the pH to 9, and add 3-chloro-2-hydroxypropyltrimethylammonium chloride while stirring. The mass ratio of pretreated tungsten trioxide powder and 3-chloro-2-hydroxypropyltrimethylammonium chloride is 1:0.2. After adding, continue stirring and heat for 1 hour, adjust the pH to 6.5, filter and take the solid, wash with water 5 times, and dry at 80℃ for 12 hours to obtain quaternized tungsten trioxide powder; (3) Add 6 g of vanadium pentoxide to 25 mL of 1 mol / L sodium hydroxide solution and stir for 20 min to generate sodium vanadate solution; (4) Add 50 mL of water and quaternized tungsten trioxide powder to the sodium vanadate solution. The mass ratio of quaternized tungsten trioxide powder to vanadium pentoxide is 3:1. Stir at 100 rpm for 6 hours. Filter the solid, wash it with distilled water three times, dry it at 100 ° C for 6 hours, and heat it to 350 ° C for calcination for 5 hours to obtain V2O5 / tungsten trioxide. (5) Weigh 1.1 mmol of silver nitrate to prepare a 12 mmol / L solution, add 9.5 wt% ammonia water dropwise to the solution, and shake while adding until precipitation is complete. After solid-liquid separation, pour off the supernatant and continue to add 9.5 wt% ammonia water dropwise to the solid until the initial precipitation is completely dissolved, thereby obtaining a silver ammonia solution. (6) Add V2O5 / tungsten trioxide to the silver ammonia solution, stir for 4-6 hours, filter out the solid, wash it with distilled water three times, and dry it at 100℃ for 12 hours to obtain silver vanadate / tungsten oxide; (7) At room temperature, 600 mg of graphite oxide was dispersed in 600 mL of water, and then 1.5 g of sodium dodecylbenzenesulfonate was added. After ultrasonic treatment for 2 h, a graphite oxide dispersion with a concentration of 1 mg / mL was obtained. Then, 3 mL of hydrazine hydrate was added to the above graphite oxide dispersion, and the mixture was heated to 100 °C in an oil bath. After reacting for 14 h, a black reduced graphene oxide suspension was obtained. (8) Lower the oil bath reaction temperature to 80°C, add 7.31 g of aminobenzoic acid and 3.15 g of isoamyl nitrite to the reduced graphene oxide suspension in sequence, and react in the oil bath for 10 h to obtain a hydroxyl-modified reduced graphene oxide dispersion. Centrifuge and separate the solid, and dry it at 80°C for 10 h to obtain hydroxylated reduced graphene oxide. (9) Mix hydroxylated reduced graphene oxide and propylene carbonate to form a 45 wt% mixed solution, add silver vanadate / tungsten oxide, and the mass ratio of silver vanadate / tungsten oxide to hydroxylated reduced graphene oxide is 1:10. Grind at 300 r / s for 140 min, filter and collect the solid, dry at 100 °C for 6 h, and heat to 500 °C for calcination for 5 h.

[0023] Example 4; (1) Weigh 9 g of tungsten trioxide porous nanorods, disperse them in 30 mL of anhydrous ethanol, add 20 mL of 0.025 g / mL 3-aminopropane triethoxysilane ethanol solution dropwise, react for 5 h, and vacuum dry at 45 ° C for 12 h to obtain pretreated tungsten trioxide powder; (2) Add the pretreated tungsten trioxide powder to water with a mass of 5 times that of the pretreated tungsten trioxide powder, adjust the pH to 9 with alkali solution, stir and heat to 55℃, control the pH to 9, and add 3-chloro-2-hydroxypropyltrimethylammonium chloride while stirring. The mass ratio of pretreated tungsten trioxide powder and 3-chloro-2-hydroxypropyltrimethylammonium chloride is 1:0.2. After adding, continue stirring and heat-retaining for 1.5 hours, adjust the pH to 6.5, filter and obtain the solid, wash it with water 5 times, and dry it at 80℃ for 12 hours to obtain quaternized tungsten trioxide powder; (3) Add 6 g of vanadium pentoxide to 25 mL of 1 mol / L sodium hydroxide solution and stir for 20 min to generate sodium vanadate solution; (4) Add 50 mL of water and quaternized tungsten trioxide powder to the sodium vanadate solution. The mass ratio of quaternized tungsten trioxide powder to vanadium pentoxide is 2:1. Stir at 100 rpm for 6 hours. Filter the solid, wash it with distilled water three times, dry it at 100 ° C for 6 hours, and heat it to 350 ° C for calcination for 5 hours to obtain V2O5 / tungsten trioxide. (5) Weigh 1.1 mmol of silver nitrate to prepare a 12 mmol / L solution, add 9.5 wt% ammonia water dropwise to the solution, and shake while adding until precipitation is complete. After solid-liquid separation, pour off the supernatant and continue to add 9.5 wt% ammonia water dropwise to the solid until the initial precipitation is completely dissolved, thereby obtaining a silver ammonia solution. (6) Add V2O5 / tungsten trioxide to the silver ammonia solution, stir for 4-6 hours, filter out the solid, wash it with distilled water three times, and dry it at 105℃ for 12 hours to obtain silver vanadate / tungsten oxide; (7) At room temperature, 600 mg of graphite oxide was dispersed in 600 mL of water, and then 1.5 g of sodium dodecylbenzenesulfonate was added. After ultrasonic treatment for 2 h, a graphite oxide dispersion with a concentration of 1 mg / mL was obtained. Then, 3 mL of hydrazine hydrate was added to the above graphite oxide dispersion, and the mixture was heated to 100 °C in an oil bath. After reacting for 14 h, a black reduced graphene oxide suspension was obtained. (8) Lower the oil bath reaction temperature to 80°C, add 7.31 g of aminobenzoic acid and 3.15 g of isoamyl nitrite to the reduced graphene oxide suspension in sequence, and react in the oil bath for 10 h to obtain a hydroxyl-modified reduced graphene oxide dispersion. Centrifuge and separate the solid, and dry it at 80°C for 10 h to obtain hydroxylated reduced graphene oxide. (9) Mix the hydroxylated reduced graphene oxide and methyl isobutyl ketone to form a 45 wt% mixed solution, add silver vanadate / tungsten oxide, and the mass ratio of silver vanadate / tungsten oxide to hydroxylated reduced graphene oxide is 3:1. Grind at 300 r / s for 140 min, filter and collect the solid, dry at 100 °C for 6 h, and heat to 500 °C for calcination for 5 h.

[0024] Example 5; (1) Weigh 15 g of tungsten trioxide porous nanorods, disperse them in 30 mL of anhydrous ethanol, add 50 mL of 0.025 g / mL 3-aminopropanetriethoxysilane ethanol solution dropwise, react for 5 h, and vacuum dry at 45 ° C for 12 h to obtain pretreated tungsten trioxide powder; (2) Add the pretreated tungsten trioxide powder to water with a mass of 6 times that of the pretreated tungsten trioxide powder, adjust the pH to 9 with alkali solution, stir and heat to 55℃, control the pH to 9, and add 3-chloro-2-hydroxypropyltrimethylammonium chloride while stirring under heat preservation conditions. The mass ratio of pretreated tungsten trioxide powder and 3-chloro-2-hydroxypropyltrimethylammonium chloride is 1:0.3. After adding, continue stirring and heat preservation for 2 hours, adjust the pH to 6.5, filter and obtain the solid, wash with water 5 times, and dry at 80℃ for 12 hours to obtain quaternized tungsten trioxide powder; (3) Add 8 g of vanadium pentoxide to 25 mL of 1 mol / L sodium hydroxide solution and stir for 20 min to generate sodium vanadate solution; (4) Add 60 mL of water and quaternized tungsten trioxide powder to the sodium vanadate solution. The mass ratio of quaternized tungsten trioxide powder to vanadium pentoxide is 4:1. Stir at 100 rpm for 8 h. Filter the solid, wash it with distilled water 3 times, dry it at 100 ° C for 6 h, and heat it to 400 ° C for calcination for 5 h to obtain V2O5 / tungsten trioxide. (5) Weigh 1.2 mmol of silver nitrate to prepare a 15 mmol / L solution. Add 9.5 wt% ammonia water dropwise to the solution while shaking until precipitation is complete. After solid-liquid separation, discard the supernatant and continue to add 9.5 wt% ammonia water dropwise to the solid until the initial precipitation is completely dissolved, thereby obtaining a silver ammonia solution. (6) Add V2O5 / tungsten trioxide to the silver ammonia solution, stir for 6 hours, filter out the solid, wash it with distilled water three times, and dry it at 105℃ for 12 hours to obtain silver vanadate / tungsten oxide; (7) At room temperature, 600 mg of graphite oxide was dispersed in 600 mL of water, and then 1.5 g of sodium dodecylbenzenesulfonate was added. After ultrasonic treatment for 2 h, a graphite oxide dispersion with a concentration of 1 mg / mL was obtained. Then, 3 mL of hydrazine hydrate was added to the above graphite oxide dispersion, and the mixture was heated to 100 °C in an oil bath. After reacting for 14 h, a black reduced graphene oxide suspension was obtained. (8) Lower the oil bath reaction temperature to 80°C, add 7.31 g of aminobenzoic acid and 3.15 g of isoamyl nitrite to the reduced graphene oxide suspension in sequence, and react in the oil bath for 10 h to obtain a hydroxyl-modified reduced graphene oxide dispersion. Centrifuge and separate the solid, and dry it at 80°C for 10 h to obtain hydroxylated reduced graphene oxide. (9) Mix hydroxylated reduced graphene oxide and ethylene glycol ethyl ether to prepare a 55 wt% mixed solution, add silver vanadate / tungsten oxide, and the mass ratio of silver vanadate / tungsten oxide to hydroxylated reduced graphene oxide is 5:1. Grind at 500 r / s for 180 min, filter and collect the solid, dry at 100 °C for 6 h, and heat to 500 °C for calcination for 5 h.

[0025] Comparative Example: Silver vanadate, tungsten trioxide, and reduced graphene oxide were mixed and ground at a mass ratio of 3:1:0.5 at 200 r / s for 100 min, and calcined at 500° C. for 5 h to obtain a photocatalyst.

[0026] Performance Testing 1. Photocatalytic water splitting hydrogen production performance test (1) Catalyst pretreatment: 50 mg of catalyst (TiO2, P25, composite materials of Examples 1 to 4) was weighed and placed in a 50 ml beaker. 35 ml of water and 3 wt% Pt (15 ml, 0.032 mmol / L H2PtCl6) were added thereto, and ultrasonication was performed for 10 min.

[0027] (2) Reaction apparatus: Pour the treated catalyst into a reaction vessel and add 5 ml of triethanolamine as a sacrificial agent. Place the vessel in a photochemical high-pressure reactor, ensuring that the four gas outlets on the inner wall are aligned with the four gas outlets of the reactor, and seal the reactor.

[0028] (3) Chromatography operation steps 1. Open the argon cylinder to 0.4MPa and the chromatographic pressure to 0.1MPa.

[0029] 2. Use soapy water to check whether the TCD detector is ventilated.

[0030] e3. Turn on the chromatograph Power and press the Reset button.

[0031] 4. Set the column box temperature to 110°C, the injection chamber to 100°C, and the thermal conductivity cell to 100°C, and wait for the temperature to rise.

[0032] 5. Open bridge current, set the detector current to 80mA.

[0033] (4) Catalytic process 1. First, use argon to evacuate the air in the reactor 5 times and measure the chromatographic baseline.

[0034] 2. Turn on the xenon lamp and stirrer, react for 8 hours, and take samples every hour.

[0035] (5) Sample analysis 1. First, allow the soap film to grow rich foam, slowly open the needle valve, increase the air flow in the flow meter to 10ml, and immediately close the needle valve.

[0036] 2. Start analysis and sampling, the analysis time is 10 min.

[0037] After the reaction was completed for 3.8 hours, the gas chromatograph was turned off and the argon cylinder was closed.

[0038] The obtained curve was integrated and converted to 1.01% H2 standard gas to obtain the hydrogen production capacity. The experimental results are shown in Table 1.

[0039] Table 1 Hydrogen production rate umol / (g·h) Example 1 400.8 Example 2 520.3 Example 3 356.4 Example 4 411.5 Example 5 466.1 Comparative Example 220.1 2. Performance test of visible light catalytic degradation of industrial wastewater A 500 mL 0.01 g / L phenol solution was prepared, and 0.4 g of catalyst was added. After 0.5 h of sonication in the dark, the solution was subjected to photocatalytic degradation in a 500 mL photocatalytic reactor using a 500 W high-pressure xenon lamp (filtered to eliminate wavelengths below 400 nm) to simulate sunlight. The phenol solution concentration was measured every hour using the bromate method, and the degradation rate was calculated. The experimental results are shown in Table 2.

[0040] Degradation rate = (C0-C) / C0×100% Where: C0 is the original solution concentration, C is the solution concentration at illumination time t.

[0041] Table 2 Phenol degradation rate after 6 hours (%) Example 1 80 Example 2 92 Example 3 77 Example 4 85 Example 5 89 Comparative Example 70 It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed therein. Any reference in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A method for preparing a novel photocatalyst for producing hydrogen from organic wastewater, characterized in that: The method comprises the following preparation steps: (1) Add 40-60 mL of water and quaternized tungsten trioxide powder to the sodium vanadate solution, stir for 4-8 hours, filter out the solid, wash, dry, and calcine to obtain V2O5 / tungsten trioxide; (2) Add V2O5 / tungsten trioxide to the silver ammonia solution, stir for 4-6 hours, filter out the solid, wash, and dry to obtain silver vanadate / tungsten oxide; (3) Mix the hydroxylated reduced graphene oxide and the solvent to prepare a 35-55 wt% mixed solution, add silver vanadate / tungsten oxide, grind at 200-500 r / s for 100-180 min, filter and collect the solid, dry at 100 °C for 6 h, and heat to 500 °C for calcination for 5 h.

2. The method for preparing a novel photocatalyst for producing hydrogen from organic wastewater according to claim 1, characterized in that: The sodium vanadate solution in step (1) is prepared from vanadium pentoxide and sodium hydroxide.

3. The method for preparing a novel photocatalyst for producing hydrogen from organic wastewater according to claim 1, characterized in that: In step (1), the mass ratio of quaternized tungsten trioxide powder to vanadium pentoxide is 1-5:

1.

4. The method for preparing a novel photocatalyst for producing hydrogen from organic wastewater according to claim 1, characterized in that: The drying temperature in step (1) is 100°C.

5. The method for preparing a novel photocatalyst for producing hydrogen from organic wastewater according to claim 1, characterized in that: In step (1), the calcination temperature is 300-400° C. and the calcination time is 5 h.

6. The method for preparing a novel photocatalyst for producing hydrogen from organic wastewater according to claim 1, characterized in that: The drying temperature in step (2) is 100-105°C.

7. The method for preparing a novel photocatalyst for producing hydrogen from organic wastewater according to claim 1, characterized in that: The hydroxylated reduced graphene oxide in step (3) is prepared from reduced graphene oxide, aminobenzoic acid and isoamyl nitrite.

8. The method for preparing a novel photocatalyst for producing hydrogen from organic wastewater according to claim 1, characterized in that: In step (3), the mass ratio of silver vanadate / tungsten oxide to hydroxylated reduced graphene oxide is 1-10:1-10.

9. The method for preparing a novel photocatalyst for producing hydrogen from organic wastewater according to claim 1, characterized in that: The solvent in step (3) includes one or more of xylene, propylene glycol methyl ether, propylene carbonate, methyl isobutyl ketone and ethylene glycol ethyl ether.

10. A novel photocatalyst according to any one of claims 1 to 9 for directly producing hydrogen from wastewater and simultaneously degrading organic matter in the wastewater.