The latest progress in the design and application of semiconductor photocatalysis systems for degradation of environmental pollutants in wastewater: Mechanism insight and theoretical calculations

The application of the photocatalysis process in pollution control has attracted a lot of interest due to the growing seriousness of environmental water problems. Photocatalysis technology has quickly risen to the forefront of sustainable wastewater treatments thanks to rapid advances in the development of innovative photocatalysts, in which solar energy can be stored, transported, and converted into chemical form. This comprehensive report summarizes the latest progress in the design and application of semiconductor photocatalysis systems for boosted removal of environmental pollutants and enhanced photoreaction mechanisms. The current work introduces deep concepts about the electron transfer mechanism that were not discussed in previous works, supported by experimental characterizations and DFT theoretical calculations. Furthermore, the recent advances in the detoxification of wastewater pollutants and the generation of reactive species have been highlighted and reinforced by a huge amount of impactful literature. Beyond that, the degradation pathways, structure optimization, and toxicity assessment of organic pollutants have been argued using LC-MS, DFT calculation, and the Toxicity Estimation Software Tool. Intensively, the latest developments in the design and construction of heterojunction systems, like Z-scheme heterojunction, Schottky heterojunction, Type I/Type II heterojunctions, and p-n heterojunction, were described in detail. The experimental and DFT theoretical technologies confirmed that the creation of the heterojunction plays a crucial role in accelerating electron migration and upgrading the photocatalytic mechanism. On the other hand, our review discusses some common types of composite photocatalysts, like metal oxide-based photocatalysts, bismuth-based photocatalysts, and metal-organic frameworks (MOFs)-based photocatalysts. Moreover, several environmental factors that impact the photocatalytic reaction, including pH, pollutant concentration, photocatalyst loading, the effect of scavengers, and light power, are explained in detail. This summary may be helpful for readers in providing comprehensive information about photocatalysis systems and their sustainable advantages.