Review on CdS-derived photocatalysts for solar photocatalytic applications – Advances and challenges

The photocatalytic technology has recently attracted extensive attention because of its potential to address the energy crisis and environmental concerns. The design of an efficient and visible-light-driven photocatalyst is essential to meet the large-scale application perquisites. As a n-type semiconductor, CdS has gained widespread attention in the domain of photocatalysis due to its low-cost, biocompatibility, excellent structural and electrical properties, ability to harvest visible light due to a small energy gap, and high negative conduction band potential to perform the reduction reaction. However, due to photocorrosion caused by self-oxidation of sulfur ions and rapid recombination of photoinduced electron/hole pairs, the photocatalytic activity of CdS is still limited to laboratory research. To promote novel concepts for increasing photocatalytic efficiency, widely researched CdS-derived photocatalysts are preferred, and regulating approaches that boost their activity are presented. This review focuses on the most recent synthetic methods and strategies for tailoring CdS-derived photocatalysts for enhanced photocatalytic performances with high redox capacity, efficient sunlight utilization, and high separation of photoinduced electron/hole pairs. Besides, the photocatalytic mechanisms for different applications using modified CdS catalysts are deeply explored to emphasize the supporting function of the modification strategies.