Recent developments on AgI based heterojunction photocatalytic systems in photocatalytic application

Abstract Over the past years, photocatalytic technology has exhibited a great potential in treating wastewater, splitting water to hydrogen and reducing CO2 to fuel. Among, more and more researchers attempt to design AgI based heterojunction photocatalytic systems for developing novel photocatalysts with excellent performance. However, a review about AgI based photocatalytic systems is still absent. Herein, two the charge carrier transfer processes in Type II and Z-scheme heterojunction photocatalytic system were firstly presented systemically. Then the recent developments of AgI based different heterojunction photocatalytic systems were summarized. The photocatalysts commonly modified by AgI are classified, and the role of AgI in different heterojunction photocatalytic systems is analyzed in detail. Additionally, the application of AgI based composites in environmental restoration and energy conversion field are presented including degradation of pollutants, photocatalytic hydrogen generation, carbon dioxide reduction and disinfection. Meanwhile, the typical mechanism of these photocatalytic reactions based on AgI composites is also described in detail. Finally, unresolved challenges and potential applications of AgI based composites are presented for guiding the direction for future development.