Preparation method, product and application of silver molybdate@titanium@network titanium dioxide
Technical Field
The invention relates to a nano photocatalytic material and preparation and application thereof, in particular to a preparation method, a product and application of silver molybdate@titanium@network titanium dioxide.
Background
With the development of the chemical industry, environmental pollution is increasingly serious. The discharge of printing and dyeing wastewater is one of the important causes of water pollution. There is a large amount of commercial dye emissions each year, and these dyes are chemically stable and cause great harm to the ecological environment. The characteristic that the semiconductor oxide material can be stimulated and activated under the irradiation of sunlight is utilized, so that organic matters can be effectively oxidized and degraded into small molecules such as carbon dioxide, water and the like. Compared with the traditional purification method, the semiconductor photocatalysis technology has the advantages of mild reaction condition, no secondary pollution, simple operation, obvious degradation effect and the like. Titanium dioxide is one of the photocatalysts of great interest, which is low-toxic, low-cost, durable, super-hydrophilic and has excellent photochemical stability.
Titanium dioxide (TiO 2) is paid attention to as a photocatalytic material, and under the illumination condition, the TiO2 can oxidize organic pollutants in water, so that the photocatalytic technology has great breakthrough in the field of treating organic pollutants in water phase and gas phase. Since then, photocatalytic degradation of organic pollutants has become one of the hot areas.
In order to improve the catalytic efficiency of TiO2 as a photocatalyst, various means have been employed to modify the material. The TiO2 is coated, so that the spectral absorption range of the material is remarkably improved, and the effective separation and transmission of photo-generated charges are promoted, so that the photocatalytic performance of the material is improved. Silver molybdate is also an important photocatalyst, and silver molybdate materials have a narrow spectral response range and low photogenerated carrier separation efficiency. Coating the titanium dioxide with the catalyst further improves the electrochemical performance of the material.
The invention provides a preparation method of silver molybdate@titanium@network titanium dioxide. Firstly preparing Ti@TiO by a one-step synthesis method, and then further carrying out secondary coating of silver molybdate, wherein the photocatalytic performance of titanium dioxide can be improved by the secondary coating. The preparation process is relatively simple and easy to operate.
Disclosure of Invention
In order to overcome the defect that the existing titanium dioxide has insufficient photocatalytic performance, the invention aims to: a preparation method of silver molybdate@titanium@network titanium dioxide is provided.
Still another object of the present invention is: there is provided a silver molybdate @ titanium @ network titanium dioxide product obtained by the above method.
Yet another object of the present invention is: there is provided the use of the above product.
The invention aims at realizing the following scheme: the preparation method of the silver molybdate@titanium@network titanium dioxide is characterized by preparing the silver molybdate@titanium@network titanium dioxide by a two-step chemical solution method, and comprises the following specific steps of:
(1) Adding 4-6 g of soluble titanium salt and 1.6-2.4 g of strong alkali into deionized water, stirring for 1-2 h until uniform, transferring the mixed solution into a three-neck flask, continuously stirring for 20-30 min, and then introducing inert gas for 20-30 min;
(2) Adding 100-150 mu L of ethanol into the mixed solution, dissolving 12-16 g of reducing agent into deionized water, rapidly adding the reducing agent solution into the solution in the stirring process, centrifuging after 15-20 min, and washing 3-5 times by using deionized water and absolute ethanol to obtain three-dimensional aerogel network Ti@TiO;
(3) Adding 0.02-0.04 mmol of silver salt into 10-15 mL of oleylamine, magnetically stirring to form a mixed solution, then introducing inert gas Ar gas into the mixed solution for 20-30 min, and gradually heating the mixed solution to 120-150 ℃ to completely dissolve the silver salt to form a solution;
(4) Injecting alcohol into the solution, wherein the molar ratio of silver salt to alcohol is 1:4, magnetically stirring for 30-60 min at the temperature, then heating to 160-180 ℃, keeping the reaction mixture at the temperature for 20-30 min, and naturally cooling to room temperature to obtain A;
(5) Adding Ti@TiO obtained in the step (2) and the A obtained in the step (4) into an ammonium molybdate solution, uniformly stirring, heating and evaporating the solvent, and calcining in a muffle furnace at 500-700 ℃ for 3-5 h to obtain B, namely: silver molybdate @ titanium @ network titanium dioxide.
Preferably, in the step (1), the titanium salt is one of tetrabutyl titanate or tetraisopropyl titanate or a combination thereof.
Preferably, in the step (1), the strong base is one or a combination of sodium hydroxide and potassium hydroxide.
Preferably, in the step (1), the inert gas is one of argon or nitrogen or a combination thereof.
Preferably, in the step (2), the reducing agent is one or a combination of hydrazine hydrate and sodium borohydride.
Preferably, in the step (3), the silver salt is one or a combination of silver acetate, silver nitrate and silver chlorate.
Preferably, in the step (4), the alcohol is one or a combination of ethylene glycol and glycerol.
The invention provides silver molybdate@titanium@network titanium dioxide which is prepared by any one of the above methods.
The invention provides an application of a silver molybdate@titanium@network titanium dioxide photocatalytic material in wastewater treatment.
The beneficial effects are that:
the invention provides a preparation method of silver molybdate@titanium@network titanium dioxide. Firstly preparing Ti@TiO by a one-step synthesis method, and then further carrying out secondary coating of silver molybdate, wherein the photocatalytic performance of titanium dioxide can be improved by the secondary coating. The preparation process is relatively simple and easy to operate. The silver molybdate@titanium@network titanium dioxide firstly reaches equilibrium on the adsorption of the tetracycline in darkness, and then reaches 99.8% on the degradation of the tetracycline after 60min under the ultraviolet light catalysis condition.
Drawings
FIG. 1 is a graph of ultraviolet light catalyzed degradation of example 1 silver molybdate @ titanium @ network titanium dioxide.
Fig. 2 is an SEM image of example 2 silver molybdate @ titanium @ network titanium dioxide.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Embodiment one:
(1) Adding 4g of soluble tetrabutyl titanate and 1.6g of strong alkali sodium hydroxide into deionized water, stirring for 1h to uniformity, transferring the mixed solution into a three-neck flask, continuously stirring for 20min, and then introducing inert gas argon for 20min;
(2) Adding 100 mu L of ethanol into the mixed solution, dissolving 12g of reducing agent sodium borohydride into deionized water, rapidly adding sodium borohydride solution into the solution in the stirring process, centrifuging after 15min, and washing 3 times with deionized water and absolute ethanol to obtain three-dimensional aerogel network Ti@TiO;
(3) Adding 0.02mmol of silver nitrate into 10mL of oleylamine, magnetically stirring to form a mixed solution, then introducing inert gas Ar gas into the mixed solution for 20min, and gradually heating the mixed solution to 120 ℃ to completely dissolve the silver nitrate to form a solution;
(4) Ethylene glycol was injected into the above solution, wherein the molar ratio of silver nitrate to ethylene glycol was 1:4, magnetically stirring for 30min at the temperature, then heating to 160 ℃, keeping the reaction mixture at the temperature for 20min, and naturally cooling to room temperature to obtain A;
(5) Adding Ti@TiO obtained in the step (2) and the A obtained in the step (4) into an ammonium molybdate solution, uniformly stirring, heating and evaporating the solvent, and calcining in a muffle furnace at 500 ℃ for 5 hours to obtain B, namely: silver molybdate @ titanium @ network titanium dioxide.
FIG. 1 is a graph of ultraviolet light catalyzed degradation of silver molybdate @ titanium @ network titanium dioxide. The silver molybdate@titanium@network titanium dioxide firstly reaches equilibrium on the adsorption of the tetracycline in darkness, and then reaches 99.8% on the degradation of the tetracycline after 60min under the ultraviolet light catalysis condition.
Example 2
(1) Adding 5g of soluble tetraisopropyl titanate and 2g of strong alkali potassium hydroxide into deionized water, stirring for 1.5h to uniformity, transferring the mixed solution into a three-neck flask, continuously stirring for 25min, and then introducing inert gas nitrogen for 25min;
(2) Adding 120 mu L of ethanol into the mixed solution, dissolving 14g of reducing agent hydrazine hydrate in deionized water, rapidly adding a hydrazine hydrate solution into the solution in the stirring process, centrifuging after 20min, and washing with deionized water and absolute ethanol for 5 times to obtain three-dimensional aerogel network Ti@TiO;
(3) Adding 0.04mmol of silver acetate into 15mL of oleylamine, magnetically stirring to form a mixed solution, then introducing inert gas Ar gas into the mixed solution for 25min, and gradually heating the mixed solution to 150 ℃ to completely dissolve the silver acetate to form a solution;
(4) Injecting glycerol into the solution, wherein the molar ratio of the silver acetate to the glycerol is 1:4, magnetically stirring for 60min at the temperature, then heating to 180 ℃, keeping the reaction mixture at the temperature for 25min, and naturally cooling to room temperature to obtain A;
(5) Adding Ti@TiO obtained in the step (2) and the A obtained in the step (4) into an ammonium molybdate solution, uniformly stirring, heating and evaporating the solvent, and calcining in a muffle furnace at 600 ℃ for 4 hours to obtain B, namely: silver molybdate @ titanium @ network titanium dioxide.
FIG. 2 is an SEM image of silver molybdate@titanium@network titanium dioxide, which shows that the image is a three-dimensional network structure with the particle size of 200-300 nm.
Example 3
(1) Adding 6g of soluble tetraisopropyl titanate and 2.4g of strong alkali sodium hydroxide into deionized water, stirring for 2 hours until the mixture is uniform, transferring the mixed solution into a three-neck flask, continuously stirring for 30 minutes, and then introducing inert gas argon for 30 minutes;
(2) Adding 150 mu L of ethanol into the mixed solution, dissolving 116g of reducing agent sodium borohydride into deionized water, rapidly adding sodium borohydride solution into the solution in the stirring process, centrifuging after 20min, and washing 3 times with deionized water and absolute ethanol to obtain three-dimensional aerogel network Ti@TiO;
(3) Adding 0.04mmol of silver chlorate into 15mL of oleylamine, magnetically stirring to form a mixed solution, then introducing inert gas Ar gas into the mixed solution for 30min, and gradually heating the mixed solution to 150 ℃ to completely dissolve silver salt to form a solution;
(4) Ethylene glycol was injected into the above solution, wherein the molar ratio of silver chlorate to ethylene glycol was 1:4, magnetically stirring for 60min at the temperature, then heating to 180 ℃, keeping the reaction mixture at the temperature for 30min, and naturally cooling to room temperature to obtain A;
(5) Adding Ti@TiO obtained in the step (2) and the A obtained in the step (4) into an ammonium molybdate solution, uniformly stirring, heating and evaporating the solvent, and calcining in a muffle furnace at 700 ℃ for 3 hours to obtain B, namely: silver molybdate @ titanium @ network titanium dioxide.