LDHs Catalysts for CO2 Photocatalytic Reduction (A Review)

Photocatalytic CO2 reduction is considered a promising green approach that can concurrently achieve sustainable energy production and mitigate climate change. However, the sluggish reaction kinetics and the complexity of multiple reaction pathways present substantial challenges to enhancing product generation rates and selectivity. Among various catalysts, layered double hydroxides (LDHs), as anion intercalation materials, have garnered considerable attention due to their ultrathin layered structure, tunable chemical composition, and modifiable transition metal d-electron configuration. These properties endow LDHs with broad spectral absorption, efficient carrier migration, and abundant active sites. In recent years, a considerable body of research has emerged focusing on LDHs catalyst; however, comprehensive reviews and summaries of these advancements remain scarce. This paper aims to systematically review the progress in regulating LDH structures for enhanced photocatalytic CO2 reduction. It begins by introducing the photocatalytic CO2 reduction mechanism and the structural characteristics of LDH photocatalysts. Subsequently, it summarizes methods for modifying the electronic structure of LDH photocatalysts through defect engineering, morphology control, single-atom modification, element doping, and heterojunction construction. These optimizations could improve light absorption, electron-hole separation and migration, and surface reduction reactions, thereby enhancing photocatalytic performance. Finally, the paper addresses the challenges faced by LDH photocatalytic systems and outlines future research directions.