Photocatalytic Degradation of Acetic Acid Wastewater by Novel Catalysts

With the acceleration of industrialization, acetic acid is an important chemical product, and its production process will produce a large amount of wastewater containing acetic acid. These wastewater not only cause serious pollution to the environment, but also pose a threat to the ecological balance. As a green, efficient and sustainable wastewater treatment method, photocatalytic technology has shown great potential in the treatment of acetic acid wastewater. In recent years, significant progress has been made in the research of new catalysts for photocatalytic degradation of acetic acid wastewater. This article will analyze the types, mechanisms and research progress of catalysts.

1. Photocatalytic degradation of acetic acid wastewater basic principle

The core of photocatalytic technology is to use the electronic transition of semiconductor materials under the condition of light, so as to trigger the redox reaction. Under the action of photocatalyst, light energy is absorbed and converted into electron kinetic energy, which in turn decomposes organic pollutants (such as acetic acid) into harmless small molecules, such as carbon dioxide and water. This technology can not only treat acetic acid wastewater efficiently, but also avoid the problem of secondary pollution in traditional treatment methods.

2. Catalyst type and its mechanism

At present, the research on photocatalytic degradation of acetic acid wastewater mainly focuses on the development of new photocatalysts. Common catalyst types include metal oxides (e. g., TiO₂, ZnO), composite catalysts (e. g., metal-oxide composites), and non-metallic catalysts (e. g., graphene, carbon nanotubes). The following are some typical catalysts and their mechanisms of action:

2.1 metal oxide photocatalyst

Metal oxide photocatalyst is one of the most widely studied photocatalysts. Among them, TiO₂ is widely used in acetic acid wastewater treatment because of its high chemical stability, non-toxicity and good photocatalytic performance. Traditional TiO₂ has low absorption efficiency in the visible light range, which limits its application. To this end, the researchers modified TiO₂ by doping, heterojunction construction and other methods to significantly improve its photocatalytic activity.

2.2 composite catalyst

Composite catalysts are usually composed of two or more materials to make up for the lack of a single catalyst. For example, the graphene-TiO₂ composite material significantly improves the carrier transmission efficiency and light absorption capacity of TiO₂ through the conductivity and large area specific surface area of graphene. Researchers have also developed other types of composite catalysts, such as metal oxide-metal organic framework (MOFs) composites, which have large specific surface area and excellent light absorption properties.

2.3 non-metallic catalyst

Non-metallic catalysts (such as g-C3N4 and graphene) have shown good performance in the field of photocatalysis due to their unique electronic structure and energy band distribution. For example, due to its wide light absorption range and low band gap, g-C3N4 can effectively remove energy in visible light and show high catalytic efficiency in acetic acid degradation. Its catalytic performance can be further improved by regulating its structure (such as layered stacking, nitrogen doping, etc.).

3. Photocatalytic degradation of acetic acid wastewater research progress

In recent years, the research of photocatalytic degradation of acetic acid wastewater has made remarkable progress. The following are some representative research directions:

3.1 Catalyst Energy Band Regulation

By adjusting the band structure of the photocatalyst, its photocatalytic performance can be significantly improved. For example, by defect engineering, heterojunction construction and other methods, the band gap of the photocatalyst can be reduced, so that it has a higher absorption efficiency in the visible light range. Studies have shown that the photocatalyst with a narrow band gap can work in a wider spectral range, thereby significantly improving the degradation efficiency of acetic acid.

3.2 catalyst morphology control

The morphology of the catalyst (such as nanorods, nanosheets, porous structure, etc.) has an important influence on its photocatalytic performance. Studies have shown that photocatalysts with larger specific surface area and appropriate pore structure can provide more active sites, thereby improving the degradation efficiency of acetic acid. For example, by controlling the synthesis conditions, the researchers successfully prepared TiO₂ nanosheets with a porous structure, and their photocatalytic activity was significantly improved.

3.3 Visible Light Responsive Catalysts

Traditional photocatalysts mainly rely on ultraviolet light excitation, and visible light occupies the main part of sunlight. Therefore, the development of visible light-responsive photocatalyst is of great significance. In recent years, researchers have successfully developed a series of visible light-responsive photocatalysts, such as Cu₂ O, Ag₂ O, etc., by introducing metal impurities and non-metal doping. These catalysts showed high photocatalytic activity under visible light irradiation, which provided a new idea for the treatment of acetic acid wastewater.

4. Photocatalytic degradation of acetic acid wastewater future development direction

Although photocatalytic technology has made significant progress in the treatment of acetic acid wastewater, it still faces some challenges. Future research directions may include the following:

4.1 development of multifunctional composite catalyst

The multifunctional composite catalyst can further improve the photocatalytic efficiency by combining the advantages of different materials. For example, combining metal oxide with graphene, carbon nanotubes and other materials can not only improve the light absorption ability, but also enhance the electron transport performance.

4.2 improve catalyst stability and reusability

At present, many photocatalysts have problems such as poor stability and easy agglomeration in practical applications. Therefore, the development of photocatalysts with high stability and reusability is an important direction of future research.

4.3 development of intelligent photocatalytic system

With the development of artificial intelligence and automation technology, intelligent photocatalytic system has gradually become a research hotspot. Through the introduction of sensors, intelligent control algorithms and other technologies, the photocatalytic process can be automated and efficient.

5. Conclusion

Photocatalytic technology as an efficient and environmentally friendly acetic acid wastewater treatment method has received extensive attention in recent years. The development of new photocatalyst provides important technical support for the treatment of acetic acid wastewater. Although a series of research results have been achieved, the photocatalytic technology still needs further efforts in the performance optimization, stability improvement and practical application promotion of the catalyst. In the future, with the rapid development of nanotechnology, artificial intelligence and other fields, the application prospect of photocatalytic technology in acetic acid wastewater treatment will be broader.