Immobilization of metal active centers in reticular framework materials for photocatalytic energy conversion

To enhance the economy and society's sustainability, prioritizing innovative, green energy conversion methods is essential. The conversion of solar energy into chemical energy through photocatalysis represents a viable solution in the pursuit of sustainable energy resources despite low solar-to-energy conversion efficiency. In recent years, the immobilization of metal active centers in nanospace has been considered an important strategy to improve photocatalytic performance. Metal-organic frameworks (MOFs), covalent organic frameworks (COFs) and hydrogen-bonded organic frameworks (HOFs), as exciting reticular framework materials, have attracted much attention due to their advantages of large specific surface area, high porosity and tunable functionalization sites, which are considered promising carriers for immobilizing metal sites. This paper introduces the structural features and advantages of each framework in photocatalysis, highlighting their potential applications in water splitting (H₂ or O₂ evolution) and CO₂ reduction. The review underscores the outstanding performance of metal-active sites within these frameworks. Finally, the current limitations and challenges of the reticular framework materials in photocatalysis are pointed out, and an outlook for future development is provided, which aims to inspire continued advancements in green energy solutions for a sustainable future.