Construction of a 3D/2D g-C3N4/ZnIn2S4 hollow spherical heterostructure for efficient CO2 photoreduction under visible light†
A 3D/2D g-C3N4/ZnIn2S4 hollow spherical heterostructure was constructed by growing modified ZnIn2S4 nanosheets on the surface of g-C3N4 microspheres. This composite material can not only take advantage of the hollow structure with a stronger light absorption capacity and more active sites, but its heterostructure can also increase the efficiency of photogenerated electron migration and separation, thereby improving the serious photogenerated electron recombination of two separate materials. The unique structural superiority led to excellent photocatalytic CO2 reduction performance, where a higher CO generation rate reaching 7368.7 μmol g−1 h−1 by using IZIS–CN100 was undoubtedly strong evidence. The heterojunction formation process and the subsequent electronic changes on both theoretical and experimental aspects of the combination of electrochemical tests and density functional theory (DFT) were verified. Finally, we proposed a feasible photocatalytic mechanism and brought forth new ideas in the application of materials, structural control, and the combination of theories and experiments.