Polymeric Carbon Nitride-Derived Photocatalysts for Water Splitting and Nitrogen Fixation

Photocatalysis is a promising energy conversion and environmental restoration technology. The main focus of photocatalysis is the development and manufacture of highly efficient photocatalysts. Semiconductor-based photocatalysis technology based on harnessing solar energy is considered as an attractive approach to solve the problems of global energy shortage and environmental pollution. Since 2009 pioneering work has been carried out on polymeric carbon nitride (PCN) for visible photocatalytic water splitting, thus PCN-based photocatalysis has become a hot research topic, demanding significant research attention. This article reviews the physical and chemical properties, synthesis methods, and the methods to control the morphology, heteroatom doping, and construction of heterojunctions to improve the performance of PCN-based photocatalysts in water splitting and nitrogen fixation. Through different design strategies, the photo-generated electron-hole pair separation efficiency of PCN materials can be effectively improved, thereby improving their photocatalytic performance. Finally, the challenges of PCN-based photocatalysts in water splitting and nitrogen fixation applications are discussed herein. It is strongly believed that through different design strategies, efficient PCN-based photocatalysts can be constructed for both water splitting and nitrogen reduction. These excellent modification strategies can be used as a guiding theory for photocatalytic reactions of other promising catalysts and further promote the development of photocatalysis.