阅读说明：本技术 一种光电极及其制备方法和应用 (Photoelectrode and preparation method and application thereof ) 是由 范东华 张云波 黄吉儿 梁胜华 孙史巍 于 2021-01-18 设计创作，主要内容包括：本发明公开了一种光电极及其制备方法和应用,用两次电化学沉积法制备FTO/BiVO-4/Cu-2O光电极；将所述FTO/BiVO4/Cu-2O光电极用于光电催化水氧化反应过程；所述FTO/BiVO4/Cu-2O光电极中BiVO-4晶型为单斜结构,其孔隙为10-80nm,粒子尺寸为50-200nm；Cu-2O的粒子尺寸约为0.8-1.5μm；BiVO-4沉积在FTO上,沉积厚度为650-750nm；Cu-2O沉积在FTO/BiVO-4上,沉积厚度为1-100nm；所述BiVO-4与Cu-2O沉积的摩尔比为1:4-32,各自电解液中的Bi与Cu的摩尔比为1：8。本发明所述的FTO/BiVO-4/Cu-2O光电极可提高单纯BiVO-4载流子分离,光电催化性能优异,稳定性大大增强；基于BiVO-4和Cu-2O的复合光电极,可以提高光电催化分解水的性能,提高太阳能的利用与转换效率；本发明所述方法操作简单,相比于对比例3的水热合成法,电化学沉积法大大缩短生产时间,提高生产效率。(The invention discloses a photoelectrode, a preparation method and application thereof, and an FTO/BiVO prepared by a twice electrochemical deposition method 4 /Cu 2 An O-photo electrode; mixing the FTO/BiVO4/Cu 2 The O-shaped photoelectrode is used for photoelectrocatalysis water oxidation reaction process; the FTO/BiVO4/Cu 2 BiVO in O-photoelectrode 4 The crystal form is a monoclinic structure, the pore space is 10-80nm, and the particle size is 50-200 nm; cu 2 The particle size of O is about 0.8-1.5 μm; BiVO 4 Depositing on FTO with a deposition thickness of 650-750 nm; cu 2 O is deposited on FTO/BiVO 4 Depositing to a thickness of 1-100 nm; what is needed isBiVO 4 And Cu 2 The molar ratio of O deposition is 1:4-32, the molar ratio of Bi to Cu in the respective electrolytes is 1: 8. the invention relates to an FTO/BiVO 4 /Cu 2 The O-shaped photoelectrode can improve pure BiVO 4 The carrier separation, excellent photoelectrocatalysis performance and greatly enhanced stability; based on BiVO 4 And Cu 2 The composite photoelectrode of O can improve the performance of photoelectrocatalysis water decomposition and improve the utilization and conversion efficiency of solar energy; compared with the hydrothermal synthesis method of comparative example 3, the electrochemical deposition method greatly shortens the production time and improves the production efficiency.)

1. FTO/BiVO4/Cu₂An O-electrode, wherein the FTO/BiVO4/Cu₂BiVO in O-photoelectrode₄The crystal form is a monoclinic structure, the pore space is 10-80nm, and the particle size is 50-200 nm; cu₂The particle size of O is about 0.8 to 1.5 μm.

2. The FTO/BiVO4/Cu of claim 1₂An O-photoelectrode, characterized by BiVO₄Depositing on FTO with a deposition thickness of 650-750 nm; cu₂O is deposited on FTO/BiVO₄And the deposition thickness is 1-100 nm.

3. The FTO/BiVO4/Cu of claim 1₂An O-photoelectrode, wherein the BiVO₄And Cu₂The molar ratio of O deposition is 1:4-32, the molar ratio of Bi to Cu in the respective electrolytes is 1: 8.

4. FTO/BiVO4/Cu₂The preparation method of the O-shaped photoelectrode is characterized by comprising the following steps:

s1: adding bismuth nitrate into potassium iodide solution, performing ultrasonic treatment, stirring uniformly, and adjusting the pH value to 0.5-3.5 by using acid solution;

s2: adding an ethanol solution of p-benzoquinone into the solution obtained in S1, uniformly stirring, and adjusting the pH value to 3-3.5 by using an acid solution to obtain a BiOI electrolyte;

s3: depositing the BiOI on the FTO by using the BiOI electrolyte obtained in S2 to obtain FTO/BiOI;

s4: dripping the dimethyl sulfoxide solution of vanadyl acetylacetonate onto the FTO/BiOI, and annealing to obtain an electrode;

s5: removing excessive V from the electrode obtained in S4 with NaOH solution₂O₅Drying the mixture under an infrared lamp to obtain FTO/BiVO₄Standby;

s6: in CuSO₄Adding DL-lactic acid into the aqueous solution, and adjusting the pH to 11-13 with an alkali solution to obtain Cu₂An electrolyte of O;

s7: FTO/BiVO obtained from S5₄As a working electrode, Cu obtained in S6 was used₂O in an electrolyte oil bath, Cu₂Electrochemical deposition of O to FTO/BiVO₄Drying by an infrared lamp to obtain FTO/BiVO4/Cu₂And an O-shaped photoelectrode.

5. An FTO/BiVO4/Cu according to claim 4₂The preparation method of the O-shaped photoelectrode is characterized in that the concentration of a potassium iodide solution in S1 is 0.2-0.6 mol/L; the concentration of bismuth nitrate in the electrolyte is 0.02-0.06 mol/L; the ultrasonic treatment time is 5-20 min; the stirring time is 10-40 min.

6. An FTO/BiVO4/Cu according to claim 4₂The preparation method of the O-shaped photoelectrode is characterized in that the concentration of an ethanol solution of p-benzoquinone in S2 is 0.1-0.4 mol/L; the concentration of vanadyl acetylacetonate in S4 is 0.1-0.5mol/L, the annealing heating rate is 1-3 ℃/min, and the annealing temperature is 350-650 ℃; the annealing time is 1-4 h.

7. An FTO/BiVO4/Cu according to claim 4₂The preparation method of the O-shaped photoelectrode is characterized in that the concentration of sodium hydroxide in S5 is 1-2mol/L, such as 1.5mol/L, and the drying time under an infrared lamp in S5 and S7 is 5-10 min.

8. An FTO/BiVO4/Cu according to claim 4₂The preparation method of the O-shaped photoelectrode is characterized in that CuSO in S6₄The concentration of the compound is 0.3-0.5mol/L, and the concentration of the DL-lactic acid is 2-4 mol/L.

9. An FTO/BiVO4/Cu according to claim 4₂The preparation method of the O-shaped photoelectrode is characterized in that the oil bath temperature in S7 is 50-70 ℃, and the electrodeposition time is 10-300S.

10. FTO/BiVO4/Cu₂The application of the O-shaped photoelectrode is characterized in that the FTO/BiVO4/Cu is used₂The O-shaped photoelectrode is used for photoelectrocatalysis water oxidation reaction process.

Technical Field

The invention belongs to the field of preparation of photoelectrode materials, and particularly relates to FTO/BiVO₄/Cu₂An O-shaped photoelectrode, a preparation method and application thereof, and is used for photoelectrocatalysis water decomposition driven by sunlight.

Background

With the increasing environmental pollution and energy crisis in the world, the search and development of sustainable clean energy is not slow, and therefore the development and utilization of green energy has become one of the most important challenges facing mankind at present. The photoelectrocatalysis technology can directly complete conversion from solar energy to chemical energy, when the energy irradiated by sunlight is larger than the band gap of a semiconductor catalyst, electrons on a conduction band of the catalyst are excited to jump to the conduction band, and then electron-hole pairs are formed, and photocurrent can be formed under external voltage and is detected by an electrochemical workstation. The photoelectrocatalysis technology is one of effective ways to solve the energy problem.

BiVO₄The semiconductor material is a yellow, safe, non-toxic, green and cheap semiconductor material, the band gap of the semiconductor material is very suitable for water photolysis at the band gap width of 2.4eV, the semiconductor material is a photoelectrode material with good visible light response capability, and the photoelectric conversion efficiency at the 420nm position reaches 29%. However, the carrier separation is slow and the recombination is very easy, so that the application of the carrier separation in photoelectrocatalysis is limited. The carrier separation and carrier recombination can be improved and slowed by methods such as recombination, for example, Xu et al (S.Xu, D.Fu, K.Song, L.Wang, Z.Yang, W.Yang, H.Hou Chemical Engineering Journal 2018,349,368-375) synthesizes BiVO₄/WO₃The composite material is used for photoelectrocatalysis. However, the preparation method has the advantages of complex operation, long time consumption, high cost and low product performance, and the prepared photoelectrode cannot meet the requirements of photoelectrocatalysis.

Disclosure of Invention

The present invention is directed to at least solving the above problemsOne of the technical problems existing in the prior art. Therefore, the invention provides FTO/BiVO4/Cu₂O-photoelectrode to improve simple BiVO₄The current carrier is separated, the photoelectrocatalysis performance is excellent, and the stability is greatly enhanced.

The invention also provides the FTO/BiVO4/Cu₂The preparation method of the O-shaped photoelectrode is simple to operate, greatly shortens the production time and improves the production efficiency.

The invention further provides the FTO/BiVO4/Cu₂The application of the O photoelectrode is to use the FTO/BiVO4/Cu₂The O-shaped photoelectrode is used for photoelectrocatalysis water oxidation reaction process.

According to one aspect of the invention, FTO/BiVO4/Cu is provided₂O-electrode, the FTO/BiVO4/Cu₂The O-shaped photoelectrode is formed by growing BiVO on the surface of a conductive glass substrate (FTO) through twice electrochemical deposition₄And Cu₂O。

In some embodiments of the invention, BiVO₄The crystal form is a monoclinic structure, the pore space is 10-80nm, and the particle size is 50-200 nm; cu₂The particle size of O is about 0.8 to 1.5 μm.

In some preferred embodiments of the invention, BiVO₄Depositing on FTO with a deposition thickness of 650-750 nm; cu₂O is deposited on FTO/BiVO₄And the deposition thickness is 1-100 nm.

In some more preferred embodiments of the invention, BiVO₄And Cu₂The molar ratio of O deposition is such that the molar ratio of Bi to Cu in the respective electrolytes is 1: 8.

according to another aspect of the invention, FTO/BiVO4/Cu is provided₂The preparation method of the O-shaped photoelectrode comprises the following specific steps:

s1: adding bismuth nitrate into potassium iodide solution, performing ultrasonic treatment, stirring uniformly, and adjusting the pH value to 0.5-3.5 by using acid solution;

s2: adding an ethanol solution of p-benzoquinone into the solution obtained in S1, uniformly stirring, and adjusting the pH value to 3-3.5 by using an acid solution to obtain a BiOI electrolyte;

s3: in a three-electrode electrolytic cell, depositing the BiOI on the FTO by using the BiOI electrolyte obtained in S2 to obtain FTO/BiOI;

s4: dripping the dimethyl sulfoxide solution of vanadyl acetylacetonate onto the FTO/BiOI, and annealing to obtain an electrode;

s5: removing excess V from the electrode obtained in S4 with sodium hydroxide solution₂O₅Drying the mixture under an infrared lamp to obtain FTO/BiVO₄Standby;

s6: in CuSO₄Adding DL-lactic acid into the aqueous solution, and adjusting the pH to 11-13 with an alkali solution to obtain Cu₂An electrolyte of O;

s7: FTO/BiVO obtained from S5₄As a working electrode, Cu obtained in S6 was used₂O in an electrolyte oil bath, Cu₂Electrochemical deposition of O to FTO/BiVO₄Drying the mixture under an infrared lamp to obtain FTO/BiVO4/Cu₂And an O-shaped photoelectrode.

In some embodiments of the invention, the concentration of the potassium iodide solution in S1 is 0.2 to 0.6mol/L, preferably 0.3 to 0.5mol/L, such as 0.2mol/L, 0.3mol/L, 0.4mol/L, 0.5mol/L, 0.6 mol/L; the concentration of bismuth nitrate in the electrolyte is 0.02-0.06mol/L, preferably 0.03-0.05mol/L, such as 0.02mol/L, 0.03mol/L, 0.04mol/L, 0.05mol/L, 0.06 mol/L; the ultrasonic treatment time is 5-20min, preferably 10-15min, such as 10min, 11min, 12min, 13min, 14min, and 15 min; stirring for 10-40min, preferably 20-30min, such as 20min, 22min, 24min, 26min, 28min, 30 min; the acid solution is selected from any one of hydrochloric acid solution and nitric acid solution, preferably nitric acid solution.

In some preferred embodiments of the present invention, the concentration of the ethanol solution of p-benzoquinone in S2 is 0.1 to 0.4mol/L, preferably 0.3 mol/L; the acid solution is selected from any one of hydrochloric acid solution and nitric acid solution, preferably nitric acid solution.

In some preferred embodiments of the invention, a platinum wire is used as a counter electrode and a saturated silver/silver chloride electrode is used as a reference electrode in the three-electrode electrolytic cell in S3 and 7.

In some preferred embodiments of the present invention, the concentration of vanadyl acetylacetonate in S4 is 0.1-0.5mol/L, preferably 0.2-0.4mol/L, such as 0.1mol/L, 0.2mol/L, 0.3mol/L, 0.4mol/L, 0.5mol/L, the annealing temperature rise rate is 1-3 ℃/min, preferably 2 ℃/min, the annealing temperature is 350-; the annealing time is 1-4h, preferably 2-3 h.

In some more preferred embodiments of the invention, the concentration of sodium hydroxide in S5 is 1-2mol/L, for example 1.5 mol/L.

In some more preferred embodiments of the invention, the drying time under an infrared lamp in S5, 7 is 5-10min, preferably 6-8min, such as 5min, 6min, 7min, 8min, 9min, 10 min.

In some more preferred embodiments of the invention, CuSO in S6₄The concentration of (B) is 0.3-0.5mol/L, preferably 0.4mol/L, the concentration of DL-lactic acid is 2-4mol/L, preferably 3mol/L, and the alkaline solution is preferably NaOH solution.

In some more preferred embodiments of the invention, the oil bath temperature in S7 is in the range of 50-70 ℃, preferably 55-65 ℃, e.g. 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, and the electrodeposition time is in the range of 10S-300S, preferably 50-200S, e.g. 20S, 80S, 100S, 150S, 160S, 180S, 250S, 270S, 300S.

FTO/BiVO4/Cu₂The application of the O-shaped photoelectrode is characterized in that the FTO/BiVO4/Cu is used₂The O-shaped photoelectrode is used for photoelectrocatalysis water oxidation reaction process.

According to yet another aspect of the invention, the BiVO is based₄And Cu₂The O composite photoelectrode can improve the performance of photoelectrocatalysis water decomposition, improve the utilization and conversion efficiency of solar energy, more effectively photoelectrocatalysis water decomposition to generate hydrogen, and can use the FTO/BiVO4/Cu₂The O-shaped photoelectrode is used for photoelectrocatalysis water oxidation reaction process.

The invention has the following remarkable effects:

1. the invention provides FTO/BiVO4/Cu₂O-photoelectrode to improve simple BiVO₄The carrier separation, the photoelectrocatalysis performance is excellent, and the stability is greatly enhanced; based on BiVO₄And Cu₂O-type composite photo-electrodeThe performance of photoelectrocatalysis water decomposition can be improved, the utilization and conversion efficiency of solar energy can be improved, and the photoelectrocatalysis performance of the composite material is obviously improved as can be seen from figure 5;

2. compared with the hydrothermal synthesis method of comparative example 3, the electrochemical deposition method greatly shortens the production time and improves the production efficiency.

Drawings

FIG. 1 is a flow chart of examples 1 to 4 of the present invention

FIG. 2 is a color comparison chart of photoelectrodes prepared in comparative example 1, comparative example 2, inventive example 1 and inventive example 2

FIG. 3 is a comparative XRD pattern of photoelectrodes prepared in comparative example 1, comparative example 2, inventive example 1 and example 2

FIG. 4 is SEM images of photoelectrodes prepared in comparative example 1, comparative example 2, and examples 1 and 2 of the present invention

Fig. 5 is a graph comparing the photoelectrocatalytic current density versus time for photoelectrodes prepared in comparative example 1, inventive example 1, and example 2.

Detailed Description

The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.

In which electrochemical deposition and Photoelectrocatalysis (PEC) are both performed on chenhua CHI 660 e.

Example 1

FTO/BiVO4/Cu₂The preparation method of the O-shaped photoelectrode comprises the following specific steps:

s1: adding bismuth nitrate into potassium iodide solution, performing ultrasonic treatment, stirring uniformly, and adjusting the pH value to 3.4 by using nitric acid solution;

s2: adding an ethanol solution of p-benzoquinone into the solution obtained in S1, uniformly stirring, and adjusting the pH of the electrolyte to 3.4 by nitric acid to obtain a BiOI electrolyte;

s3: in a three-electrode electrolytic cell, depositing the BiOI on the FTO by using the BiOI electrolyte obtained in S2 to obtain FTO/BiOI;

s4: dripping the dimethyl sulfoxide solution of vanadyl acetylacetonate onto the FTO/BiOI, and annealing to obtain an electrode;

s5: removing excess V from the electrode obtained in S4 with sodium hydroxide solution₂O₅Drying the mixture under an infrared lamp to obtain FTO/BiVO₄Standby;

s6: in CuSO₄Adding DL-lactic acid into the aqueous solution, adjusting the solution to 12.5 with NaOH to obtain Cu₂An electrolyte of O;

s7: FTO/BiVO obtained from S5₄As a working electrode, Cu obtained in S6 was used₂O in an electrolyte oil bath, Cu₂Electrochemical deposition of O to FTO/BiVO₄Drying the mixture under an infrared lamp to obtain FTO/BiVO4/Cu₂And an O-shaped photoelectrode.

Further, the concentration of the potassium iodide solution in S1 was 0.4mol/L, and the concentration of bismuth nitrate in the electrolyte was 0.04 mol/L. Ultrasonic treating for 10min, and stirring for 20 min.

Further, the concentration of the ethanol solution of p-benzoquinone in S2 was 0.2 mol/L.

Furthermore, the concentration of vanadyl acetylacetonate in S4 is 0.2mol/L, the annealing temperature rise rate is 2 ℃/min, and the annealing temperature rise rate is 2h at 450 ℃.

Further, the concentration of sodium hydroxide in S5 was 1mol/L, and the drying time under infrared lamp in S5, 7 was 10 min.

Further, CuSO in S6₄The concentration of (2) is 0.32mol/L, and the concentration of DL-lactic acid is 3 mol/L.

Further: in S7, the bath temperature is 60 deg.C, and electrodeposition is carried out for 20S.

Example 2

FTO/BiVO4/Cu₂The preparation method of the O-shaped photoelectrode comprises the following specific steps:

s1: adding bismuth nitrate into potassium iodide solution, performing ultrasonic treatment, stirring uniformly, and adjusting the pH value to 1.65 by using nitric acid solution;

s2: adding an ethanol solution of p-benzoquinone into the solution obtained in S1, uniformly stirring, and adjusting the pH of the electrolyte to 3.4 by nitric acid to obtain a BiOI electrolyte;

s3: in a three-electrode electrolytic cell, depositing the BiOI on the FTO by using the BiOI electrolyte obtained in S2 to obtain FTO/BiOI;

s4: dripping the dimethyl sulfoxide solution of vanadyl acetylacetonate onto the FTO/BiOI, and annealing to obtain an electrode;

s5: removing excess V from the electrode obtained in S4 with sodium hydroxide solution₂O₅Drying the mixture under an infrared lamp to obtain FTO/BiVO₄Standby;

s6: in CuSO₄Adding DL-lactic acid into the aqueous solution, adjusting the solution to 12.5 with NaOH to obtain Cu₂An electrolyte of O;

s7: FTO/BiVO obtained from S5₄As a working electrode, Cu obtained in S6 was used₂O in an electrolyte oil bath, Cu₂Electrochemical deposition of O to FTO/BiVO₄Drying the mixture under an infrared lamp to obtain FTO/BiVO4/Cu₂And an O-shaped photoelectrode.

Further, the concentration of the potassium iodide solution in S1 was 0.4mol/L, and the concentration of bismuth nitrate in the electrolyte was 0.04 mol/L. Ultrasonic treating for 10min, and stirring for 20 min.

Further: the concentration of the ethanol solution of p-benzoquinone in S2 was 0.2 mol/L.

Further: the concentration of vanadyl acetylacetonate in S4 is 0.2mol/L, the annealing heating rate is 2 ℃/min, and the annealing heating rate is 2h at 450 ℃.

Further: the concentration of sodium hydroxide in S5 is 1mol/L, and the drying time under an infrared lamp in S5 and S7 is 10 min.

Further: CuSO in S6₄The concentration of (2) is 0.32mol/L, and the concentration of DL-lactic acid is 3 mol/L.

Further: in S7, the bath temperature is 60 deg.C, and electrodeposition is carried out for 50S.

Example 3

FTO/BiVO4/Cu₂The preparation method of the O-shaped photoelectrode comprises the following specific steps:

s1: adding bismuth nitrate into potassium iodide solution, performing ultrasonic treatment, stirring uniformly, and adjusting the pH value to 3.5 by using nitric acid solution;

s2: adding an ethanol solution of p-benzoquinone into the solution obtained in S1, uniformly stirring, and adjusting the pH of the electrolyte to 3.5 by nitric acid to obtain a BiOI electrolyte;

s3: in a three-electrode electrolytic cell, depositing the BiOI on the FTO by using the BiOI electrolyte obtained in S2 to obtain FTO/BiOI;

s4: dripping the dimethyl sulfoxide solution of vanadyl acetylacetonate onto the FTO/BiOI, and annealing to obtain an electrode;

s5: removing excess V from the electrode obtained in S4 with sodium hydroxide solution₂O₅Drying the mixture under an infrared lamp to obtain FTO/BiVO₄Standby;

s6: in CuSO₄Adding DL-lactic acid into the aqueous solution, adjusting the solution to 13 with NaOH to obtain Cu₂An electrolyte of O;

s7: FTO/BiVO obtained from S5₄As a working electrode, Cu obtained in S6 was used₂O in an electrolyte oil bath, Cu₂Electrochemical deposition of O to FTO/BiVO₄Drying the mixture under an infrared lamp to obtain FTO/BiVO4/Cu₂And an O-shaped photoelectrode.

Further, the concentration of the potassium iodide solution in S1 was 0.6mol/L, and the concentration of bismuth nitrate in the electrolyte was 0.06 mol/L. Ultrasonic treating for 20min, and stirring for 40 min.

Further: the concentration of the ethanol solution of p-benzoquinone in S2 was 0.4 mol/L.

Further: the concentration of vanadyl acetylacetonate in S4 is 0.5mol/L, the annealing heating rate is 3 ℃/min, and the annealing heating rate is 650 ℃ for 4 h.

Further: the concentration of sodium hydroxide in S5 is 2mol/L, and the drying time under an infrared lamp in S5 and S7 is 7 min.

Further: CuSO in S6₄The concentration of (2) is 0.5mol/L, and the concentration of DL-lactic acid is 4 mol/L.

Further: in S7, the bath temperature is 70 deg.C, and electrodeposition is carried out for 300S.

Example 4

FTO/BiVO4/Cu₂The preparation method of the O-shaped photoelectrode comprises the following specific steps：

S1: adding bismuth nitrate into potassium iodide solution, performing ultrasonic treatment, stirring uniformly, and adjusting the pH value to 0.5 by using nitric acid solution;

s2: adding an ethanol solution of p-benzoquinone into the solution obtained in S1, uniformly stirring, and adjusting the pH of the electrolyte to 3 by nitric acid to obtain a BiOI electrolyte;

s3: in a three-electrode electrolytic cell, depositing the BiOI on the FTO by using the BiOI electrolyte obtained in S2 to obtain FTO/BiOI;

s4: dripping the dimethyl sulfoxide solution of vanadyl acetylacetonate onto the FTO/BiOI, and annealing to obtain an electrode;

s5: removing excess V from the electrode obtained in S4 with sodium hydroxide solution₂O₅Drying the mixture under an infrared lamp to obtain FTO/BiVO₄Standby;

s6: in CuSO₄Adding DL-lactic acid into the aqueous solution, adjusting the solution to 11 with NaOH to obtain Cu₂An electrolyte of O;

s7: FTO/BiVO obtained from S5₄As a working electrode, Cu obtained in S6 was used₂O in an electrolyte oil bath, Cu₂Electrochemical deposition of O to FTO/BiVO₄Drying the mixture under an infrared lamp to obtain FTO/BiVO4/Cu₂And an O-shaped photoelectrode.

Further, the concentration of the potassium iodide solution in S1 was 0.2mol/L, and the concentration of bismuth nitrate in the electrolyte was 0.0.2 mol/L. Ultrasonic treating for 5min, and stirring for 10 min.

Further: the concentration of the ethanol solution of p-benzoquinone in S2 was 0.1 mol/L.

Further: the concentration of vanadyl acetylacetonate in S4 is 0.1mol/L, the annealing heating rate is 1 ℃/min, and the annealing heating rate is 4h at 350 ℃.

Further: the concentration of sodium hydroxide in S5 is 1mol/L, and the drying time under an infrared lamp in S5 and S7 is 5 min.

Further: CuSO in S6₄The concentration of (2) is 0.3mol/L and the concentration of DL-lactic acid is 2 mol/L.

Further: in S7, the bath temperature is 50 deg.C, and electrodeposition is carried out for 10S.

Comparative example 1

A kind ofFTO/BiVO₄The preparation method of the photoelectrode comprises the following specific steps:

s1: adding bismuth nitrate into potassium iodide solution, performing ultrasonic treatment, stirring uniformly, and adjusting the pH value to 3.4 by using nitric acid solution;

s2: adding an ethanol solution of p-benzoquinone into the solution obtained in S1, uniformly stirring, and adjusting the pH of the electrolyte to 3.4 by nitric acid to obtain a BiOI electrolyte;

s3: in a three-electrode electrolytic cell, depositing the BiOI on the FTO by using the BiOI electrolyte obtained in S2 to obtain FTO/BiOI;

s4: dripping the dimethyl sulfoxide solution of vanadyl acetylacetonate onto the FTO/BiOI, and annealing to obtain an electrode;

s5: removing excess V from the electrode obtained in S4 with sodium hydroxide solution₂O₅Drying under an infrared lamp to obtain FTO/BiVO₄An electrode;

further, the concentration of the potassium iodide solution in S1 was 0.4mol/L, and the concentration of bismuth nitrate in the electrolyte was 0.04 mol/L. Ultrasonic treating for 10min, and stirring for 20 min.

Further, the concentration of the ethanol solution of p-benzoquinone in S2 was 0.2 mol/L.

Furthermore, the concentration of vanadyl acetylacetonate in S4 is 0.2mol/L, the annealing temperature rise rate is 2 ℃/min, and the annealing temperature rise rate is 2h at 450 ℃.

Further, the temperature for infrared lamp drying in S5 was 10 min.

Comparative example 2

FTO/Cu₂The preparation method of the O-shaped photoelectrode comprises the following specific steps:

s1: in CuSO₄Adding DL-lactic acid into the aqueous solution, adjusting the solution to 11 with NaOH to obtain Cu₂An electrolyte of O;

s2: cu obtained in S1 using FTO as a working electrode₂O in an electrolyte oil bath, Cu₂O is electrochemically deposited on the FTO and is dried under an infrared lamp to obtain FTO/Cu₂And an O-shaped photoelectrode.

Further, CuSO in S1₄The concentration of (2) is 0.32mol/L, and the concentration of DL-lactic acid is 3 mol/L.

Further: in S2, the bath temperature is 60 deg.C, and electrodeposition is carried out for 50S. The temperature for infrared lamp drying is 10 min.

Comparative example 3

FTO/BiVO₄/Cu₂The O hydrothermal preparation method comprises the following specific steps:

s1: at HNO₃Adding Bi (NO) into the solution₃)₃·5H₂O and NH₄VO₃Stirring for 1 hour on a magnetic stirrer;

s2: adding CO (NH) to the solution obtained in S1₂)₂And then heated with stirring at 80 ℃ for 24 h. Then washing with deionized water and drying to obtain BiVO₄；

S3: BiVO obtained from S2₄0.01mol of the Cu is taken and put into deionized water, and CuCl is added according to different molar ratios of Bi and Cu₂·2H2O；

S4: adding PVP into the solution obtained in S3, adjusting the pH value to be alkalescent by alkali, adding water and hydrazine, stirring for 1h at 45 ℃, and then washing and drying to obtain BiVO₄/Cu₂A complex of O;

s5: the complex obtained in S4 was ultrasonically dispersed in ethanol and Nafion (a membrane solution), and then dropped on FTO, and dried under an infrared lamp to obtain FTO/BiVO₄/Cu₂And an O electrode.

Further, HNO in S1₃At a concentration of 1 mol/L30 mL, Bi (NO)₃)₃·5H₂Mass of O2.91 g, NH₄VO₃Has a mass of 0.7204 g.

Further, CO (NH) in S2₂)₂The mass of (3) was 3 g. Drying in an oven at 65 ℃.

Further, in S4, the pH was adjusted to 8.5, the mass of PVP was 0.5g, and the concentrations of water and hydrazine were 0.1mol/L and 0.8 mL.

Further, 2mg of BiVO in S5₄/Cu₂O was added to 180uL of ethanol and 20uL of Nafion solution. The infrared lamp drying time was 10 min.

From FIG. 2, a yellow BiVO can be observed₄Brick red Cu2O and compound BiVO₄/Cu₂The sample of O on FTO proves the successful preparation of the composite material; figure 3 can intuitively embody BiVO₄、Cu₂The characteristic diffraction peak of O and the change of the diffraction peak after the recombination indicate FTO/BiVO₄/Cu₂The preparation of the O composite photoelectrode is successful; FIG. 4 is the morphology of the synthesized photoelectrode observed under a field scanning electron microscope, and BiVO can be seen₄The shape and size of the smaller particles are about 100nm, and Cu₂O is the square block shape with the shape of about 1um, and the composite FTO/BiVO₄/Cu₂The morphology on O can find Cu₂Covering BiVO with O₄Upper side; fig. 5 is a diagram of the performance of photoelectrocatalysis, and a relationship between current density measured on an electrochemical workstation and time shows that the current density is almost close to 0 when a light source simulating sunlight is not turned on, when the light source is turned on, the catalyst is excited to see that the photocurrent density is suddenly generated, and when the light source is turned off, the photocurrent disappears instantly, the magnitude of the photocurrent density can intuitively illustrate the strength of the photoelectrocatalysis, and we can clearly see that the photoelectrocatalysis performance of the composite material is obviously improved.

The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.