Co–In Bimetallic Hydroxide Nanosheet Arrays With Coexisting Hydroxyl and Metal Vacancies Anchored on Rod‐Like MOF Template for Enhanced Photocatalytic CO2 Reduction

Layered double hydroxides (LDHs) can serves as catalysts for CO₂ photocatalytic reduction (CO₂PR). However, the conventionally synthesized LDHs undergo undesired aggregation, which results in an insufficient number of active sites and limits the desirable electron transfer required for CO₂PR. The metal-organic framework (MOF) template-grown LDHs demonstrate excellent promise for exploiting the strengths of both MOFs and LDHs. Herein, the in situ growth of MIL-68(In)-NH₂ MOF-templated Co-In bimetallic catalyst (CoIn-LDH/MOF) having an ultrathin nanosheet morphology on the preserved rod-like MOF template is demonstrated. Compared to the conventionally grown bimetallic LDH (CoIn-LDH), CoIn-LDH/MOF not only exposes more active sites but also possesses hydroxyl vacancies (V_OH) and Co vacancies (V_Co). Thus, CoIn-LDH/MOF performs a higher CO generation rate of 2320 µmol g^-1 h^-1 during CO₂PR, demonstrating improved activity and selectivity than those in CoIn-LDH. Experiments coupled with calculations reveal that the CoIn-LDH/MOF-driven CO₂PR follows the ^*COOH pathway. The lower energy barriers for the formation of ^*COOH and CO(g) can be attributed to the coexistence of V_OH and V_Co in CoIn-LDH/MOF, effectively promoting charge transfer and enhancing CO₂PR performance. This study provides a new strategy to obtain high-performant LDH-based catalysts with improved morphology.