A comprehensive review highlights the photocatalytic heterojunctions and their superiority in the photo-destruction of organic pollutants in industrial wastewater

Abstract

Visible-light-driven photochemistry is an attractive strategy for solar light utilization and renewable energy harvesting for environmental improvement. To obtain a powerful photochemical reaction, it is necessary to construct an efficient, stable, and cost-effective semiconductor system. Herein, we try to provide a comprehensive review to discuss the new strategies that have been proven by recent impactful investigations to improve photocatalytic systems and their applications in industrial wastewater treatment. Particularly, the preferred characteristics, such as strong redox ability, appropriate band edge positions, long-term stability, efficient charge-separation efficiency, and narrow band gap energy, are required to improve the photodegradation rate of photocatalysts against different organic pollutants in wastewater. Therefore, numerous modification technologies, like element doping, defect engineering, heterojunction construction, and morphological optimization, were outlined to control the photodegradation ability of developed photo-systems. In addition, the review involves some sophisticated technologies to fabricate different nano-semiconductor photocatalysts. Besides, our study introduces some vital factors like photocatalyst loading, reaction temperature, pH value, light intensity, substrate concentration, scavengers, and catalyst morphology that influence the photoreaction. Finally, we believe that the findings of this discussion will help to develop efficient and cost-effective photocatalytic systems for eliminating organic pollutants in industrial wastewater.