CN-122006752-A - Heterojunction photocatalyst and preparation method and application thereof

Abstract

The invention relates to the technical field of photocatalytic degradation, in particular to a heterojunction photocatalyst and a preparation method and application thereof. The preparation method of the heterojunction photocatalyst comprises the following steps of respectively dissolving a Bi source and a V source in water to obtain a Bi source solution and a V source solution, mixing the Bi source solution and the V source solution to form a stable suspension, adding an alkaline solution into the stable suspension until a reaction system is neutral, performing hydrothermal reaction to obtain Bi 2 O 3 /BiVO 4 , dispersing a Cd source in water to obtain a Cd source solution, adding a sulfur source and Bi 2 O 3 /BiVO 4 into the Cd source solution, performing ultrasonic treatment, and then performing heating reaction to obtain the heterojunction photocatalyst. The heterojunction photocatalyst (Bi 2 O 3 /BiVO 4 /CdS) prepared by the method of the invention has excellent photocatalytic degradation activity on pollutants such as tetracycline hydrochloride and the like.

Inventors

• WANG MENG
• DENG YIPING
• FU ZHONGHUI
• CHEN XIANGDONG

Assignees

• 东北农业大学

Dates

Publication Date

20260512

Application Date

20260130

Claims (10)

1. 1. The preparation method of the heterojunction photocatalyst is characterized by comprising the following steps of: the preparation method comprises the steps of 1, respectively dissolving a Bi source and a V source in water to obtain a Bi source solution and a V source solution, mixing the Bi source solution and the V source solution to form a stable suspension, adding an alkaline solution into the stable suspension until a reaction system is neutral, and then carrying out hydrothermal reaction to obtain Bi 2 O 3 /BiVO 4 ; and step 2, dispersing a Cd source in water to obtain a Cd source solution, adding a sulfur source and Bi 2 O 3 /BiVO 4 into the Cd source solution for ultrasonic treatment, and then heating for reaction to obtain the heterojunction photocatalyst.
2. 2. The method of preparing a heterojunction photocatalyst as claimed in claim 1, wherein in the step 1, the Bi source is Bi (NO 3 ) 3 ·5H 2 O; the V source is NH 4 VO 3 .
3. 3. The method of preparing a heterojunction photocatalyst as claimed in claim 1, wherein in the step 1, the alkaline solution is 0.1-2M NH 3 ·H 2 O.
4. 4. The method for preparing a heterojunction photocatalyst as claimed in claim 1, wherein in the step 1, the temperature of the hydrothermal reaction is 150-180 ℃ and the time is 10-16 h.
5. 5. The method for preparing the heterojunction photocatalyst as claimed in claim 1, wherein the mass fraction of Bi 2 O 3 in Bi 2 O 3 /BiVO 4 -20%.
6. 6. The method for preparing a heterojunction photocatalyst as claimed in claim 1, wherein in the step 2, the Cd source is CdCl 2 ·2.5H 2 O, the sulfur source is thioacetamide, and the molar ratio of the Cd source to the sulfur source is 1:1.
7. 7. The method of preparing a heterojunction photocatalyst as claimed in claim 1, wherein in the step 2, the heating reaction is performed at a temperature of 80-95 ℃ for a time of 1.5-3 h.
8. 8. The method for preparing the heterojunction photocatalyst as claimed in claim 1, wherein the mass percentage of Bi 2 O 3 /BiVO 4 in the heterojunction photocatalyst is 5% -25%.
9. 9. A heterojunction photocatalyst prepared by the preparation method of any one of claims 1 to 8.
10. 10. The use of the heterojunction photocatalyst of claim 9, wherein the contaminant is tetracycline hydrochloride, oxytetracycline, metronidazole, or myclobutanil in photocatalytic degradation of the contaminant.

Description

Heterojunction photocatalyst and preparation method and application thereof Technical Field The invention relates to the technical field of photocatalytic degradation, in particular to a heterojunction photocatalyst and a preparation method and application thereof. Background The pollutants such as tetracycline hydrochloride, terramycin, metronidazole, myclobutanil and the like have the characteristics of strong chemical stability and difficult degradation, and long-term accumulation can destroy ecological balance and even harm human health through a food chain, so that the development of efficient water pollutant degradation technology is urgent. The photocatalytic degradation technology is one of ideal means for treating organic pollutants by virtue of the advantages of environmental protection, mild conditions, no secondary pollution and the like, and the core of the photocatalytic degradation technology is to develop a photocatalyst with excellent performance. Among the many semiconductor photocatalysts, bismuth vanadate (BiVO 4) is of great interest due to its unique energy band structure. Compared with the traditional wide bandgap semiconductor, the BiVO 4 has good visible light response characteristic, can effectively improve photon utilization efficiency, has structural stability and excellent environmental compatibility brought by a chemical inert framework, has a surface structure which is easy to modify and regulate, and has wide application prospect in the field of pollutant degradation. However, biVO 4 as a narrow bandgap semiconductor has an inherent defect of fast recombination rate of photo-generated electrons and holes, which severely limits further improvement of photocatalytic activity, so that degradation efficiency in actual wastewater treatment is difficult to meet requirements. To overcome this deficiency, researchers have attempted to optimize the photocatalytic performance of BiVO 4 by various modification methods, such as constructing heterojunction, elemental doping, surface modification, etc. The heterojunction construction is an effective strategy for inhibiting the recombination of photo-generated carriers and widening the photo-response range, and the BiVO 4 is compounded with other semiconductor materials, and the charge separation channel is constructed by utilizing the difference of energy band structures of different materials, so that the efficiency of the photo-catalytic reaction is improved. However, the existing composite catalyst has a plurality of defects that on one hand, the charge separation efficiency and the oxidation-reduction capability of a binary composite system are limited, the degradation efficiency of pollutants is to be improved, and on the other hand, the construction process of a ternary composite system is not mature, part of composite materials have the problems of unsmooth interface bonding, unsmooth charge transfer paths, insufficient stability and the like, the catalytic performance in complex water environment (such as anions and cations and different water quality matrixes) is easy to be influenced, and meanwhile, the broad-spectrum degradation capability of various pollutants and the toxicity control of intermediates in the degradation process still need to be further optimized. Therefore, the BiVO 4 -based heterojunction photocatalyst which has firm interface combination, high charge separation efficiency and strong stability and high efficient degradation performance on various organic pollutants in a complex environment is developed, and meanwhile, the degradation mechanism and intermediate toxicity change rule of the BiVO 4 -based heterojunction photocatalyst are clear, so that the BiVO 4 -based heterojunction photocatalyst has important significance in promoting the application of a photocatalysis technology in the actual water pollution treatment. Disclosure of Invention Based on the above, the invention provides a heterojunction photocatalyst, and a preparation method and application thereof. In order to achieve the above object, the present invention provides the following solutions: according to one of the technical schemes, the preparation method of the heterojunction photocatalyst comprises the following steps: the preparation method comprises the steps of 1, respectively dissolving a Bi source and a V source in water to obtain a Bi source solution and a V source solution, mixing the Bi source solution and the V source solution to form a stable suspension, adding an alkaline solution into the stable suspension until a reaction system is neutral, and then carrying out hydrothermal reaction to obtain Bi 2O3/BiVO4; And step 2, dispersing a Cd source in water to obtain a Cd source solution, adding a sulfur source and Bi 2O3/BiVO4 into the Cd source solution for ultrasonic treatment, and then heating for reaction to obtain the heterojunction photocatalyst. In a preferred embodiment of the present invention, in step 1, the Bi source is Bi