Preparation of single-crystal silver molybdate / titanium dioxide photocatalytic material, product and application

Abstract

The application provides a preparation method of a single-crystal silver molybdate / titanium dioxide nanometer photocatalytic material, a product and application thereof, and the single-crystal silver molybdate / titanium dioxide nanometer photocatalytic material is prepared by combining a solvothermal method and a solution chemical reflux method, the preparation process is relatively simple and easy to operate. The obtained single-crystal silver molybdate / titanium dioxide nanometer photocatalytic material is applied to degradation of methyl orange in dye wastewater treatment. In the dark, adsorption of methyl orange is first balanced, then under the condition of ultraviolet light catalysis, after 60 min, degradation of methyl orange reaches 99.7%.

Description

TECHNICAL FIELD

[0001] The present application relates to nanometer photocatalytic material and its preparation and application, and in particular to a preparation method, product and application of a single-crystal silver molybdate / titanium dioxide photocatalytic material. BACKGROUND

[0002] Discharge of printing and dyeing wastewater is one of the important reasons for water pollution. A large amount of commercial dyes are discharged every year, which are stable in chemical properties and cause great harm to the ecological environment. The semiconductor material can be activated under sunlight, which can effectively oxidize and degrade organic matter into small molecules such as carbon dioxide and water.

[0003] Silver molybdate is an important semiconductor photocatalyst in the molybdate family, which has good photocatalytic activity. However, the spectral response range of silver molybdate material is narrow, and the photogenerated carrier separation efficiency is low, so the photocatalytic efficiency in the visible light region is low. Therefore, in view of this problem, researchers prepare composite materials based on silver molybdate to expand the optical absorption range and promote the separation of photogenerated carriers, thereby greatly improving the photocatalytic performance in the visible light region.

[0004] Nanometer titanium dioxide as a photocatalyst can increase the reaction rate by 100-1000 times, and does not cause light scattering, and has a large specific surface area and a wide energy band. As an active substance, nanometer titanium dioxide can be used in various catalytic reactions and is considered to be one of the high-activity photocatalysts with the most application prospects. The combination of titanium dioxide and silver molybdate improves the photocatalytic performance of silver molybdate material to some extent.

[0005] The present application provides a preparation method of a single-crystal silver molybdate / titanium dioxide photocatalytic material. The single-crystal silver molybdate / titanium dioxide photocatalytic material is prepared by a combination of a solvothermal method and a solution chemical reflux method. The preparation process is relatively simple and easy to operate. SUMMARY

[0006] In order to overcome the insufficient photocatalytic performance of the existing silver molybdate, the present application aims to provide a preparation method of a single-crystal silver molybdate / titanium dioxide photocatalytic material.

[0007] Another purpose of the present application is to provide a single-crystal silver molybdate / titanium dioxide photocatalytic material product obtained by the above method.

[0008] Still another purpose of the present application is to provide an application of the above product.

[0009] The purpose of the present application is achieved by the following scheme: a preparation method of a single-crystal silver molybdate / titanium dioxide photocatalytic material, which is prepared by a solvothermal method in an autoclave, including the following steps:

[0010] (1) Dissolve 0.4-0.6 g PVP in ethylene glycol (18-24 mL) to obtain A;

[0011] (2) Then add the molybdenum source and the silver source to a strong alkali solution (2.0-5.0 mol / L) to obtain B;

[0012] (3) Add B to A, seal the obtained precursor solution in an autoclave, and magnetically stir at a speed of 300-500 rpm, heat and keep at 190-200°C for 4-6 h, naturally cool to room temperature, wash the residue with distilled water and anhydrous ethanol for 3-5 times, centrifugally collect the product, and dry at 60-80°C overnight in vacuum to obtain C: single-crystal silver molybdate;

[0013] (4) Add 8-10 mL of an acetylacetone solution and 12-15 mL of hydrazine hydrate to a flask containing 0.03-0.06 mol of a titanium source liquid phase and C obtained in the above step (3) in sequence, magnetically stir and reflux the mixed solution at 70-90°C for 36-48 h to obtain D;

[0014] (5) Filter D, wash with deionized water for 2-3 times, and then dry in an oven at 60-80°C to obtain a precursor powder E;

[0015] (6) Calcine E in a muffle furnace at a temperature increasing rate of 0.5-1°C / min for 1-2 h at 400-500°C to obtain a single-crystal silver molybdate / titanium dioxide photocatalytic material.

[0016] Preferably, in the step (2), the molybdenum source is one or a combination of ammonium molybdate and dimolybdenum trioxide.

[0017] Preferably, in the step (2), the silver source is one or a combination of silver acetate, silver nitrate or silver chlorate.

[0018] Preferably, in the step (2), the strong alkali is one or a combination of sodium hydroxide or potassium hydroxide.

[0019] Preferably, in the step (4), the titanium source is one or a combination of tetrabutyl titanate or tetraisopropyl titanate.

[0020] The present application provides a single-crystal silver molybdate / titanium dioxide photocatalytic material prepared according to any of the above methods.

[0021] The present application also provides an application of the single-crystal silver molybdate / titanium dioxide photocatalytic material in degrading methyl orange in dye wastewater.

[0022] Beneficial effects:

[0023] The application provides a preparation method of a single-crystal silver molybdate / titanium dioxide photocatalytic material. The single-crystal silver molybdate / titanium dioxide photocatalytic material is prepared by combining a solvothermal method and a solution chemical reflux method. The preparation process is relatively simple and easy to operate. The single-crystal silver molybdate / titanium dioxide photocatalytic material first reaches an adsorption balance of methyl orange in darkness, and then, under the condition of ultraviolet light catalysis, the degradation of the methyl orange reaches 99.7% after 60 min. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 A graph of ultraviolet light catalytic degradation of the single-crystal silver molybdate / titanium dioxide photocatalytic material of Example 1. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0026] Example 1

[0027] A single-crystal silver molybdate / titanium dioxide nano photocatalytic material is prepared by combining a solvothermal method and a solution chemical reflux method. The single-crystal silver molybdate / titanium dioxide nano photocatalytic material is prepared according to the following steps:

[0028] (1) 0.4 g of PVP is dissolved in 18 mL of ethylene glycol to obtain A;

[0029] (2) Ammonium molybdate and silver nitrate are added to a 2.0 mol / L strong alkali potassium hydroxide solution to obtain B;

[0030] (3) B is added to A, and the obtained precursor solution is sealed in an autoclave. The magnetic stirring speed is 300 rpm. The solution is heated and kept at 190°C for 4 h. The solution is naturally cooled to room temperature. The remaining substance is washed with distilled water and anhydrous ethanol for 3 times. The product is collected by centrifugation and dried at 60°C under vacuum overnight to obtain single-crystal silver molybdate C;

[0031] (4) 8 mL of an acetylacetone solution and 12 mL of hydrazine hydrate are sequentially added to a flask containing 0.03 mol of tetrabutyl titanate liquid phase and C obtained in step (3). The mixed solution is magnetically stirred and refluxed at 70°C for 36 h to obtain D;

[0032] (5) D is filtered and washed with deionized water for 2 times. Then, the precursor powder E is dried in an oven at 80°C.

[0033] (6) calcine E in a muffle furnace at a heating rate of 0.5 °C / min for 2 h at 400 °C to obtain the single-crystal silver molybdate / titanium dioxide photocatalytic material.

[0034] Figure 1 is a UV light catalytic degradation diagram of the single-crystal silver molybdate / titanium dioxide photocatalytic material. The single-crystal silver molybdate / titanium dioxide photocatalytic material first reaches an adsorption equilibrium for methyl orange in the dark, and then under the condition of UV light catalysis, the degradation of methyl orange reaches 99.7% after 60 min.

[0035] Example 2

[0036] A single-crystal silver molybdate / titanium dioxide nano photocatalytic material is prepared according to the following steps, which are similar to the steps of the example:

[0037] (1) dissolve 0.5 g of PVP in 21 mL of ethylene glycol to obtain A;

[0038] (2) add molybdenum trioxide and silver acetate to a 4.0 mol / L strong alkali sodium hydroxide solution to obtain B;

[0039] (3) add B to A, and seal the obtained precursor solution in an autoclave with a magnetic stirring speed of 400 rpm. Heat and maintain at 200 °C for 5 h, and naturally cool to room temperature. Wash the remaining material with distilled water and anhydrous ethanol 5 times, centrifugally collect the product, and dry at 80 °C under vacuum overnight to obtain single-crystal silver molybdate C;

[0040] (4) sequentially add 10 mL of acetylacetone solution and 15 mL of hydrazine hydrate to a flask containing 0.05 mol of tetraisopropyl titanate liquid phase and C obtained in step (3), and mix the solution at 80 °C with magnetic stirring and reflux for 42 h to obtain D;

[0041] (5) filter D, wash it with deionized water 3 times, and then dry it in an oven at 80 °C to obtain a precursor powder E;

[0042] (6) calcine E in a muffle furnace at a heating rate of 1 °C / min for 2 h at 450 °C to obtain the single-crystal silver molybdate / titanium dioxide photocatalytic material.

[0043] Example 3

[0044] A single-crystal silver molybdate / titanium dioxide nano photocatalytic material is prepared according to the following steps, which are similar to the steps of the example:

[0045] (1) dissolve 0.6 g of PVP in 24 mL of ethylene glycol to obtain A;

[0046] (2) add ammonium molybdate and silver chlorate to a 5.0 mol / L strong alkali sodium hydroxide solution to obtain B;

[0047] (3) B was added to A to obtain a precursor solution which was sealed in an autoclave and heated at 200°C for 4 h with a magnetic stirring speed of 500 rpm, and then naturally cooled to room temperature. The residue was washed with distilled water and anhydrous ethanol for 5 times, and the product was collected by centrifugation and dried at 80°C under vacuum overnight to obtain single crystal silver molybdate C;

[0048] (4) 10 mL of an acetylacetone solution and 15 mL of hydrazine hydrate were sequentially added to a flask containing 0.06 mol of tetrabutyl titanate liquid phase and C obtained in step (3), and the mixed solution was stirred and refluxed at 90°C for 48 h to obtain D;

[0049] (5) D was filtered, washed with deionized water for 3 times, and then dried in an oven at 80°C to obtain a precursor powder E;

[0050] (6) E was calcined at 500°C for 1 h in a muffle furnace at a heating rate of 1°C / min to obtain a single crystal silver molybdate / titanium dioxide photocatalytic material.

Claims

1. A method for preparing a single-crystal silver molybdate / titanium dioxide nano-photocatalytic material, characterized in that, The single crystal silver molybdate / titanium dioxide nano photocatalytic material is prepared by combining a solvent-thermal method with a solution chemical reflux method, and the preparation method comprises the following steps: (1) 0.4-0.6 g of PVP is dissolved in 18-24 mL of ethylene glycol to obtain A; (2) a molybdenum source and a silver source are added to a 2.0-5.0 mol / L strong alkali solution to obtain B; (3) B is added to A, and the obtained precursor solution is sealed in an autoclave, the magnetic stirring speed is 300-500 rpm, heating is performed and the temperature is kept at 190-200 DEG C for 4-6 h, natural cooling is performed to room temperature, the remaining substance is washed with distilled water and anhydrous ethanol for 3-5 times, the product is collected by centrifugation, and drying is performed at 60-80 DEG C under vacuum overnight to obtain single crystal silver molybdate C; (4) 8-10 mL of an acetylacetone solution and 12-15 mL of hydrazine hydrate are sequentially added to a flask containing 0.03-0.06 mol of a titanium source liquid phase and the C obtained in step (3), the mixed solution is magnetically stirred and refluxed at 70-90 DEG C for 36-48 h to obtain D; (5) D is filtered, washed with deionized water for 2-3 times, and then dried in an oven at 60-80 DEG C to obtain a precursor powder E; (6) E is calcined at 400-500 DEG C at a temperature increasing rate of 0.5-1 DEG C / min in a muffle furnace for 1-2 h to obtain the single crystal silver molybdate / titanium dioxide photocatalytic material. The molybdenum source is one or a combination of ammonium molybdate and dimolybdenum trioxide; The silver source is one or a combination of silver acetate, silver nitrate and silver chlorate; The strong alkali is one or a combination of sodium hydroxide and potassium hydroxide.

2. The method for preparing a single-crystal silver molybdate / titanium dioxide nanophotocatalyst material according to claim 1, characterized in that, The titanium source is one or a combination of tetrabutyl titanate and tetraisopropyl titanate.

3. The single crystal silver molybdate / titanium dioxide nano photocatalytic material is prepared by combining a solvent-thermal method with a solution chemical reflux method, and the preparation method comprises the following steps: (1) 0.4 g of PVP is dissolved in 18 mL of ethylene glycol to obtain A; (2) ammonium molybdate and silver nitrate are added to a 2.0 mol / L strong alkali potassium hydroxide solution to obtain B; (3) B is added to A, and the obtained precursor solution is sealed in an autoclave, the magnetic stirring speed is 300 rpm, heating is performed and the temperature is kept at 190 DEG C for 4 h, natural cooling is performed to room temperature, the remaining substance is washed with distilled water and anhydrous ethanol for 3 times, the product is collected by centrifugation, and drying is performed at 60 DEG C under vacuum overnight to obtain single crystal silver molybdate C; (4) 8 mL of an acetylacetone solution and 12 mL of hydrazine hydrate are sequentially added to a flask containing 0.03 mol of a tetrabutyl titanate liquid phase and the C obtained in step (3), the mixed solution is magnetically stirred and refluxed at 70 DEG C for 36 h to obtain D; (5) D is filtered, washed with deionized water for 2 times, and then dried in an oven at 80 DEG C to obtain a precursor powder E; (6) E is calcined at 400 DEG C at a temperature increasing rate of 0.5 DEG C / min in a muffle furnace for 2 h to obtain the single crystal silver molybdate / titanium dioxide photocatalytic material.

4. The single crystal silver molybdate / titanium dioxide nano photocatalytic material is prepared by combining a solvent-thermal method with a solution chemical reflux method, and the preparation method comprises the following steps: (1) 0.5 g PVP was dissolved in 21 mL ethylene glycol to obtain A; (2) Molybdenum trioxide and silver acetate were added into 4.0 mol / L strong alkali sodium hydroxide solution to obtain B; (3) B was added into A, and the obtained precursor solution was sealed in an autoclave, heated and kept at 200℃ for 5 h, and then naturally cooled to room temperature; the remaining product was washed with distilled water and anhydrous ethanol for 5 times, centrifuged to collect the product, and dried at 80℃ under vacuum overnight to obtain single crystal silver molybdate C; (4) 10 mL acetylacetone solution and 15 mL hydrazine hydrate were sequentially added into a flask containing 0.05 mol tetraisopropyl titanate liquid phase and C obtained in step (3); the mixed solution was magnetically stirred and refluxed at 80℃ for 42 h to obtain D; (5) D was filtered, washed with deionized water for 3 times, and then dried in an oven at 80℃ to obtain precursor powder E; (6) E was calcined in a muffle furnace at 450℃ with a heating rate of 1℃ / min for 2 h to obtain single crystal silver molybdate / titanium dioxide photocatalytic material.

5. The preparation method of the single crystal silver molybdate / titanium dioxide nano photocatalytic material according to any one of claims 1-2, which is prepared according to the following steps: (1) 0.6 g PVP was dissolved in 24 mL ethylene glycol to obtain A; (2) Ammonium molybdate and silver chlorate were added into 5.0 mol / L strong alkali sodium hydroxide solution to obtain B; (3) B was added into A, and the obtained precursor solution was sealed in an autoclave, heated and kept at 200℃ for 4 h, and then naturally cooled to room temperature; the remaining product was washed with distilled water and anhydrous ethanol for 5 times, centrifuged to collect the product, and dried at 80℃ under vacuum overnight to obtain single crystal silver molybdate C; (4) 10 mL acetylacetone solution and 15 mL hydrazine hydrate were sequentially added into a flask containing 0.06 mol tetrabutyl titanate liquid phase and C obtained in step (3); the mixed solution was magnetically stirred and refluxed at 90℃ for 48 h to obtain D; (5) D was filtered, washed with deionized water for 3 times, and then dried in an oven at 80℃ to obtain precursor powder E; (6) E was calcined in a muffle furnace at 500℃ with a heating rate of 1℃ / min for 1 h to obtain single crystal silver molybdate / titanium dioxide photocatalytic material.

6. A single-crystal silver molybdate / titanium dioxide nano-photocatalytic material, characterized in that The single crystal silver molybdate / titanium dioxide nano photocatalytic material is prepared according to any one of the methods of claims 1-5.

7. The use of the single crystal silver molybdate / titanium dioxide nano photocatalytic material according to claim 6 in the degradation of methyl orange in dye wastewater treatment.

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