Self‐assembly construction of NiCo LDH/ultrathin g‐C 3 N 4 nanosheets photocatalyst for enhanced CO 2 reduction and charge separation mechanism study

Abstract Graphite phase carbon nitride (g‐C 3 N 4 ) is a promising catalyst for artificial photocatalytic carbon dioxide (CO 2 ) reduction. However, the fast carrier recombination and the inadequacy of the CO 2 reduction active site in g‐C 3 N 4 block the escalation of the performance. In this work, NiCo layered double hydroxide (NiCo LDH) nanoflowers were self‐assembled with ultrathin graphite phase carbon nitride (g‐C 3 N 4 ) by an ultrasonic stirring strategy utilizing the Zeta potential difference. The formed NiCo LDH/ultrathin g‐C 3 N 4 nanosheets (LDH‐CN) photocatalysts own the merits of rich active sites and Z‐scheme heterojunction, which lead to the enhanced CO 2 reduction activity and selectivity. The highest yields of CO and CH 4 were 114.24 and 26.48 μmol·h −1 ·g −1 , which were much greater than those of g‐C 3 N 4 and LDH. Meanwhile, the enhanced selectivity for CO confirmed the strong redox ability in the LDH‐CN caused by the Z‐scheme. The heterojunction‐induced built‐in electrical field can promote the separation and migration of photoinduced electrons and holes. This study provides a theoretical basis for designing high‐performance photocatalysts.