CN109985618A - A photocatalytic material, preparation method and application of H-occupied BiVO4-OVs - Google Patents

Abstract

A kind of H for preparing occupies BiVO₄The method and its application of-OVs catalysis material, preparation method include: by the Bi (NO of certain molar weight₃)₃·5 H₂O is dissolved in glycerol；By certain molar weight NaVO₃·2 H₂O dissolves in deionized water；Mix previous solu；Mixed liquor is transferred in the autoclave of polytetrafluoroethyllining lining, 180 DEG C of holding 8h；Solvent-thermal process product is centrifugated by 10000 rpm, deionized water and ethanol washing, 60 DEG C of drying 4h；By clean solvent thermal reaction product in Muffle furnace 300 DEG C of calcining 5h；Calcined product is in Ar/H₂The 10h that anneals at a temperature of 350 DEG C in atmosphere obtains H and occupies BiVO₄- OVs catalysis material.The present invention has the advantage that optical response range is wide, catalytic activity is high, degradation rate is fast, hydrolysis ability is strong, can make effective use of solar energy.

Description

A photocatalytic material, preparation method and application of H-occupied BiVO4-OVs

technical field

The invention relates to the technical field of photocatalytic materials, in particular to a method for preparing a BiVO ₄ (BiVO ₄ -OVs) photocatalytic material in which H occupies an oxygen-containing vacancy and its application.

Background technique

With the gradual increase of environmental pollution and energy shortage, photocatalytic technology has the advantages of cleanness, environmental protection, low cost and huge energy due to the use of sunlight as energy input. It has attracted extensive attention of scientists and has good prospects for development. However, photocatalytic technology is still limited by two influencing factors, namely narrow spectral response range and low quantum efficiency. Therefore, how to broaden spectral absorption, improve solar energy utilization, and suppress the rapid recombination of photogenerated electrons and holes has become the current research topic. core and key.

The forbidden band width of bismuth vanadate (BiVO ₄ ) is 2.3-2.4 eV, and its valence band position is high enough to realize the degradation of organics by holes. The conduction band position is favorable for the reduction of photogenerated electrons, which can split water and degrade pollutants under visible light, and the edge is very close to the H _evolution potential. (PEC) one of the water-splitting photoanode materials. However, due to the short diffusion length of carriers, the photogenerated electrons and holes are easily recombined, which reduces the photoelectric catalytic performance and becomes an important factor limiting the wide application of BiVO4 _.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a method for preparing a H-occupied BiVO ₄ -OVs photocatalytic material and its application _. The light absorption range is widened, and it has excellent photocatalytic performance.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A method for preparing H-occupied BiVO ₄ -OVs photocatalytic material, comprising the following steps:

step one:

Dissolving a certain molar amount of Bi(NO ₃ ) ₃ ·5 H ₂ O in glycerol to obtain precursor solution A;

Step 2:

The precursor solution B was obtained by dissolving a certain molar amount of NaVO ₃ ·2 H ₂ O in deionized water;

Step 3:

Add solution A to solution B and stir vigorously to obtain solution C;

Step 4:

The solution C was transferred to a polytetrafluoroethylene-lined autoclave and kept at 180 °C for 8 h to obtain the synthetic product D;

Step 5:

The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

Step 6:

Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

Step seven:

The product F was annealed at 350 °C for 10 h in Ar/H ₂ atmosphere to obtain H-occupied BiVO ₄ -OVs photocatalytic materials.

The temperature range of solvothermal in the fourth step is 120°C to 200°C.

In the fourth step, the solvothermal reaction time ranges from 6 to 12 h.

In the step 6, the calcination temperature ranges from 250°C to 450°C.

The calcination time ranges from 5 h to 24 h.

In the seventh step, the annealing temperature ranges from 300°C to 400°C.

In the seventh step, the annealing time ranges from 5 h to 12 h.

In the seventh step, the ratio of Ar/H ₂ ranges from 95%: 5% to 70%: 30%.

H-occupied BiVO ₄ -OVs photocatalytic materials are applied in photocatalytic technologies, such as pollutant degradation, photo-splitting of water, etc. A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B (RhB) solution, add 20 ml of catalyst and carry out ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Beneficial effects of the present invention:

H-occupied BiVO ₄ -OVs photocatalytic materials were prepared by a solvothermal-post-annealing method. Oxygen vacancies in the composite material can absorb near-infrared light, increase active sites and convert oxygen molecules into active species to participate in redox reactions; defect states are formed under the conduction band of BiVO ₄ to reduce the forbidden band width and improve the catalyst. At the same time, as a photogenerated electron capture center, it can effectively separate electron-hole pairs and transfer them to the catalyst surface under long-wavelength excitation, inhibit the recombination of photogenerated electrons and holes, and improve the photocatalytic efficiency. When H ₂ is introduced into BiVO ₄ -OVs, the valence band of O vacancies occupied by H acts as a defect level or shallow donor level, the band gap width is reduced, the light absorption range is enlarged, and the absorbance is significantly improved. As a photocatalytic material, it has the advantages of high charge separation rate, wide light absorption range, high photocatalytic activity, fast degradation rate and strong hydrolysis ability.

Description of drawings

Figure 1 is a schematic diagram of the preparation process of H-occupied BiVO ₄ -OVs photocatalytic material;

Figure 2 is the XRD pattern of H occupied BiVO ₄ -OVs photocatalytic material;

Figure 3 is the SEM image of H occupied BiVO ₄ -OVs photocatalytic material;

Figure 4 is a Raman spectrum image of H occupied BiVO ₄ -OVs photocatalytic material;

Figure 5 shows the UV-Vis-NIR absorption images of H-occupied BiVO ₄ -OVs photocatalytic material.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Example 1

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 120 °C for 6 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 2

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The obtained H-occupied BiVO ₄ -OVs photocatalytic material is denoted as OV _H -BiVO ₄ , and its photocatalytic performance test method is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 3

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 10 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 4

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 200 °C for 12 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 5

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 250 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 6

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 7

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 350 °C for 10 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 8

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 450 °C for 12 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 9

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 300 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 5 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 10

(1) Dissolve 2.0 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 95%: 5%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 11

(1) Dissolve 1.2 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 400 ℃, Ar/H ₂ (Vol: 90%: 10%) atmosphere for 12 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 12

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

(7) The product F was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 80%: 20%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material.

The photocatalytic performance test method of the obtained H-occupied BiVO ₄ -OVs photocatalytic material is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken each time were separated from the photocatalyst and the solution by a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 13

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

The obtained product E is not calcined in a muffle furnace, nor annealed in an Ar/H ₂ reducing atmosphere, and is denoted as OV'-BiVO ₄ . The photocatalytic performance test method is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 14

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) Product E was calcined in a muffle furnace at 300 °C for 5 h to obtain product F;

The obtained product F was not annealed under the Ar/H ₂ reducing atmosphere, and was denoted as OV-BiVO ₄ , and its photocatalytic performance test method was as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Example 15

(1) Dissolve 0.4 mmol Bi(NO ₃ ) ₃ ·5 H ₂ O in 16 ml of glycerol to obtain precursor solution A;

(2) Dissolve 0.4 mmol NaVO ₃ ·2 H ₂ O in 16 ml deionized water to obtain precursor solution B;

(3) Add solution A to solution B and stir vigorously to obtain solution C;

(4) Transfer solution C to a polytetrafluoroethylene-lined autoclave, and keep it at 180 °C for 8 h to obtain synthetic product D;

(5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried at 60 °C for 4 h to obtain product E;

(6) The product E was annealed in Ar/H ₂ atmosphere at 350 ℃, Ar/H ₂ (Vol: 80%: 20%) atmosphere for 10 h to obtain H-occupied BiVO ₄ -OVs photocatalytic materials.

The obtained product E is not calcined in a muffle furnace, and is denoted as OV _H '-BiVO ₄ , and its photocatalytic performance testing method is as follows:

A 300 W Xe lamp was used as the light source, and sunlight was simulated with a cut-off filter with wavelengths less than 800 nm. Measure 50 ml of Rhodamine B solution, add 20 ml of catalyst and perform ultrasonic dispersion. Before illumination, adsorption and stirring were carried out in the dark for 30 min to make the catalyst and pollutants reach the adsorption equilibrium. After the light was turned on, 4 mL samples were taken from the reaction vessel every fixed 20 min. The samples taken out each time were separated from the photocatalyst and the solution with a high-speed centrifuge at 10,000 r/min, the supernatant was taken, and the absorbance of Rh B was measured with a UV-Vis spectrophotometer, and the degradation of the catalyst to the pollutant solution was judged according to the absorbance. efficiency.

Referring to FIG. 2, FIG. 2 is an XRD image of the H-occupied BiVO ₄ -OVs photocatalytic material. In the figure: a. Whether or not the XRD pattern of BiVO ₄ without H added after being calcined in a muffle furnace, that is, the XRD images of the samples prepared in Example 13 and Example 14; b. XRD patterns of ₄ , namely the XRD patterns of the samples prepared in Example 15 and Example 2: c. The XRD patterns of BiVO ₄ before and after adding H without muffle furnace calcination, namely the samples prepared in Example 15 and Example 13 XRD patterns of: d. The XRD patterns of BiVO ₄ containing oxygen vacancies before and after adding H after muffle furnace calcination, namely the XRD patterns of the samples prepared in Example 2 and Example 14.

Referring to Figure 3, Figure 3 is the SEM image of the BiVO ₄ -OVs photocatalytic material occupied by H, that is, the SEM image of the OV _H -BiVO ₄ photocatalytic material prepared in Example 2; it can be clearly observed that the sample has an obvious morphology and uniform size , with a radius of about 500-600 nm, with a mulberry-like structure and a rough surface, which provides more reactive sites for photocatalytic reactions and is conducive to the capture of photogenerated electrons.

Referring to FIG. 4 , FIG. 4 is a Raman spectrum image of the H-occupied BiVO ₄ -OVs photocatalytic material, namely the H-occupied BiVO ₄ -OVs photocatalytic materials prepared in Example 2, Example 13, Example 14, and Example 15 The Raman spectrum image of ; it can be observed that the peak position of OV-BiVO ₄ with oxygen vacancies is the same as that of BiVO ₄ , and the peak is lower, which can prove the existence of oxygen vacancies. At the same time, the peak of H occupied BiVO ₄ -OVs, namely OV _H -BiVO ₄ , was significantly lower than that of OV-BiVO ₄ , indicating that H partially or completely occupied oxygen vacancies. The existence of oxygen vacancies can be proved by Raman spectroscopy, and it can also be proved that H can partially or completely occupy the oxygen vacancies.

Referring to FIG. 5 , FIG. 5 is the UV-visible-near-infrared absorption image of the H-occupied BiVO ₄ -OVs photocatalytic material, that is, the H-occupied BiVO ₄ -OVs light prepared in Example 2, Example 13, Example 14, and Example 15 Ultraviolet-visible-near-infrared absorption image of the catalytic material; it can be observed that BiVO ₄ has obvious absorption within 500 nm visible light; OV-BiVO ₄ has a red-shift phenomenon compared with BiVO ₄ , and the visible light absorption range increases, which proves that oxygen vacancies have It is beneficial to expand the light response range; OV _H '-BiVO ₄ without muffle furnace calcination and H ₂ annealing has absorption in the full spectral range of 200-2500 nm, and the absorption rate reaches more than 0.4; The H ₂ annealed OV _H -BiVO ₄ has an absorptivity of over 0.9 in the full spectral range of 200-2500 nm, with a wider light absorption range and stronger light absorption capacity, and the photocatalytic activity is significantly improved.

It can be seen from the above examples that the preparation method of the H-occupied BiVO _{4 -OVs photocatalyst material provided by the present invention has simple steps, and the prepared H-occupied BiVO 4 -OVs} photocatalyst material has an increased light response range and a carrier separation rate. As a photocatalytic material, it has the advantages of high catalytic activity, fast degradation rate, and strong hydrolysis ability, providing new ideas for the efficient utilization of solar energy.

The H-occupied BiVO ₄ -OVs technology provides an opportunity to solve the band gap problem and carrier recombination problem of BiVO ₄ , the rough and porous BiVO ₄ helps to adsorb more electrons for redox reaction, and after the introduction of oxygen vacancy defects, the oxygen vacancies Absorb near-infrared light, increase the absorption range, and increase the active site. After H occupies the O vacancy, a new defect level or shallow donor level is generated, the band gap width is reduced, the light absorption range is increased, the absorbance is greatly improved, and the photocatalytic activity is significantly improved. The preparation of H-occupied BiVO ₄ -OVs photocatalytic materials is an effective and reliable way to solve the problems of wide band gap, narrow photoresponse range and easy electron-hole recombination of photocatalytic materials.

Claims (10)

1. A photocatalytic material in which H occupies BiVO ₄ -OVs, characterized in that hydrogen atoms partially or completely occupy oxygen vacancies in the BiVO ₄ structure containing oxygen vacancies. 2 . The photocatalytic material of BiVO ₄ -OVs occupied by H according to claim 1 , characterized in that it has a nano-scale mulberry-like morphology. 3 . 3. a preparation method of the photocatalytic material that H occupies BiVO ₄ -OVs, is characterized in that, comprises the following steps: The reduction reaction of BiVO4 containing oxygen vacancies in a hydrogen reducing atmosphere yields a photocatalytic material with H occupied BiVO4 _{- OVs} . 4. the preparation method of the photocatalytic material that a kind of H occupies BiVO ₄ -OVs according to claim 3, is characterized in that, described hydrogen reduction atmosphere is Ar: H _The volume ratio is 95%: 5%～70% : 30% Ar/H ₂ mixed atmosphere. 5 . The method for preparing a photocatalytic material in which H occupies BiVO ₄ -OVs according to claim 3 , wherein the reduction reaction temperature is 300-400° C. 6 . 6. The preparation method of a photocatalytic material that H occupies BiVO ₄ -OVs according to claim ₃ , wherein the BiVO ₄ containing oxygen vacancies is obtained by a method comprising the following steps: Calcination at ℃～450℃ for 5h～24h to obtain BiVO ₄ containing oxygen vacancies. 7. The preparation method of a photocatalytic material in which H occupies BiVO ₄ -OVs according to claim 6, wherein the BiVO ₄ is obtained by a method comprising the following steps: dispersing Bi(NO ₃ ) ₃ ·5 H ₂ O and a dispersion of NaVO ₃ ·2 H ₂ O were subjected to a solvothermal reaction at 120° C. to 200° C. to obtain BiVO ₄ . 8 . The method for preparing a photocatalytic material in which H occupies BiVO ₄ -OVs according to claim 7 , wherein the molar ratio of Bi(NO ₃ ) ₃ .5 H ₂ O to NaVO ₃ .2 H ₂ O is 8 . 1:1～5:1. 9. the preparation method of the photocatalytic material that a kind of H occupies BiVO ₄ -OVs according to any one of claim 3～8, it is characterised in that the concrete steps comprise: 1) Dissolve Bi(NO ₃ ) ₃ ·5 H ₂ O in glycerol to obtain precursor solution A; 2) Dissolving NaVO ₃ ·2 H ₂ O in deionized water to obtain precursor solution B; 3) Add solution A to solution B and stir vigorously to obtain solution C; the molar ratio of Bi(NO ₃ ) ₃ ·5 H ₂ O to NaVO ₃ ·2 H ₂ O is 1:1 to 5:1; solution A and solution The volume ratio of B is 1:1～5:1; 4) The solution C is transferred to a polytetrafluoroethylene-lined autoclave, and the synthetic product D is obtained after keeping it at 120℃～200℃ for 6～12 hours; 5) The solvothermal synthesis product D was centrifuged at 10,000 rpm, washed with deionized water and ethanol, and dried to obtain product E; 6) Product E is calcined in a muffle furnace at 250℃～450℃ for 5h～24h to obtain product F; 7) The product F was annealed at 300 ℃～400 ℃ in Ar/H ₂ atmosphere for 5 h～12 h to obtain H-occupied BiVO ₄ -OVs photocatalytic material; the Ar/H ₂ volume ratio was 95%:5% ~70%: 30%. 10. The application of the H-occupied BiVO ₄ -OVs photocatalytic material of claim 1 or 2 for photocatalytic degradation of pollutants.