Few-layer porous carbon nitride anchoring Co and Ni with charge transfer mechanism for photocatalytic CO2 reduction

The low specific surface area and low charge transfer efficiency of conventional graphite carbon nitride (g-C3N4) are the main obstacles to its application in photocatalytic CO2 reduction. In this paper, graphite carbon nitride was protonated by phosphoric acid (H3PO4), and a new few-layer porous carbon nitride was prepared by intercalation polymerization with doping bimetal in the cavity of g-C3N4. Under visible light irradiation, the CO formation rate of Co/Ni co-doped g-C3N4 can reach 13.55 μmol g-1 h-1, which was 3.9 times higher than that of g-C3N4 (3.49 μmol g-1 h-1). The density functional theory (DFT) calculations showed that the addition of Co and Ni in the cavity of g-C3N4 can induce bimetallic synergistic regulation of the electronic structure, thus improving the separation efficiency of charges and visible light capture ability of g-C3N4. Our work has great reference value for designing and synthesizing novel bimetallic co-doped g-C3N4 photocatalytic materials.