Self-assembly construction of NiCo LDH/ultrathin g-C_(3)N_(4) nanosheets photocatalyst for enhanced CO_(2) reduction and charge separation mechanism study

摘要

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 perfor-mance.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 26.48μmol·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.