Research progress on structural regulation of layered double hydroxides for photocatalytic CO2 reduction
Photocatalytic conversion of carbon dioxide(CO2)into solar fuel or chemicals is considered to be one of the effective ways to alleviate the energy crisis and greenhouse effect.In order to improve the activity and selectivity of CO2 photoreduction,the structure design and performance regulation of photocatalysts is critical.Among various photocatalysts,two-dimensional layered double hydroxides(LDHs)exhibit fascinating properties in the field of photocatalysis due to their adjustable composition and ratio of cations on the host layer,and exchangeable capability of interlayer guest anions.Considering the rapid development of LDHs photocatalysts,this review presents the research progress of structural regulation of LDHs for enhancing photocatalytic CO2 reduction.Firstly,the mechanism of photocatalytic CO2 reduction and the structural characteristics of LDHs photocatalysts are briefly introduced.Secondly,the electronic structure and geometric structure of LDHs photocatalysts are reviewed in terms of defect engineering,morphology and size regulation and heterojunction structure construction.The performance of the optimized LDHs is improved by enhancing light absorption,electron hole separation and migration,and surface reduction,especially by adjusting the structure of the active site to reduce the reaction energy barrier.Facing the challenges of LDHs applications for photocatalytic CO2 reduction,we finally proposed related insights and strategies for design and fabrication of LDHs,the investigation of reaction mechanism and the modification of multi-carbon products.