Recent developments in industrial organic degradation via semiconductor heterojunctions and the parameters affecting the photocatalytic process: A review study

A few years ago, the elimination of organic pollutants was given high priority due to their harmful impacts on humans, animals, and the environment. Semiconductor photocatalysis is one of the most important and promising techniques in the field of wastewater treatment for many reasons, such as ease of handling, good reproducibility, simplicity, high efficiency, and cost-friendliness. In addition, it is environmentally friendly, non-energy-intensive, nontoxic, and green technology. This review focuses on the recent progress in semiconductor heterojunctions such as Type II heterojunction, p-n heterojunction, n-n heterojunction, Z-scheme heterojunction, and S-scheme and their application in the photocatalytic degradation of different organic pollutants like organic dyes, pesticides, phenol and phenolic compounds, petroleum refinery wastewater pollutants, antibiotics, and pharmaceutical pollutants. The environmental factors affecting photocatalytic degradation activity, such as photocatalyst concentration, pollutant concentration, solution pH, light intensity, reaction temperature, photolysis, scavengers, adsorption performance in dark control, running cycles, and type of semiconductor-semiconductor heterojunction, were thoroughly discussed, helping to design an ideal photoreactor with high photocatalytic efficiency and a cost-effective process. Finally, we believe this review is necessary for future improvement in the photocatalysis process by optimizing different operation parameters and selecting a suitable heterojunction for photocatalytic degradation of industrial organic pollutants.