A Review on Cu 2 O-Based Composites in Photocatalysis: Synthesis, Modification, and Applications.

Photocatalysis technology has the advantages of being green, clean, and environmentally friendly, and has been widely used in CO 2 reduction, hydrolytic hydrogen production, and the degradation of pollutants in water. Cu 2 O has the advantages of abundant reserves, a low cost, and environmental friendliness. Based on the narrow bandgap and strong visible light absorption ability of Cu 2 O, Cu 2 O-based composite materials show infinite development potential in photocatalysis. However, in practical large-scale applications, Cu 2 O-based composites still pose some urgent problems that need to be solved, such as the high composite rate of photogenerated carriers, and poor photocatalytic activity. This paper introduces a series of Cu 2 O-based composites, based on recent reports, including pure Cu 2 O and Cu 2 O hybrid materials. The modification strategies of photocatalysts, critical physical and chemical parameters of photocatalytic reactions, and the mechanism for the synergistic improvement of photocatalytic performance are investigated and explored. In addition, the application and photocatalytic performance of Cu 2 O-based photocatalysts in CO 2 photoreduction, hydrogen production, and water pollution treatment are discussed and evaluated. Finally, the current challenges and development prospects are pointed out, to provide guidance in applying Cu 2 O-based catalysts in renewable energy utilization and environmental protection.