Construction of 2D/3D g-C3N4/ZnIn2S4 Heterojunction for Efficient Photocatalytic Reduction of CO2 under Visible Light

A 2D/3D g-C3N4/ZnIn(2)S(4 )heterojunction photocatalyst was constructed by a one-step hydrothermal method combined with a calcination process. This composite not only can use its heterostructure to improve the migration and separation of photogenerated electron-holes but also has stronger visible light utilization efficiency and CO2 adsorption capacity, thereby improving the severe charge recombination of g-C3N4 and ZnIn2S4 monomers. The g-C3N4/ZnIn2S4 heterojunction exhibits outstanding performance in CO2 photoreduction. A maximum CO production of 40 wt % g-C3N4/ZnIn2S4 composite can reach 82.26 mu mol center dot g(-1), which is 10.1 and 2.8 times as high as those of the g-C3N4 and ZnIn(2)S(4 )monomers, respectively. The heterojunction fabrication process and electronic changes were analyzed with respect to both experimental and theoretical aspects by means of photoelectrochemical measurements and density functional theory (DFT). Finally, we propose a feasible mechanism for the photocatalytic reduction of CO2 on the g-C3N4/ZnIn2S4 composite. This work could help to understand the structure regulation of carbon nitride-based materials and provides a certain guidance for the development of novel efficient and green heterojunction catalysts.