Construction of defective cerium-doped ZnIn2S4/CdS type-II heterojunction for boosting CO2 photoreduction

Photocatalytic CO 2 reduction into value-added chemicals such as CO is of great importance for carbon-neutral in the future. However, both high CO 2 activation barriers and sluggish charge kinetics make it still a challenge for CO 2 photoreduction with high reactivity. Herein, a type-II heterojunction (CZ/C), which consists of CdS (C) nanospheres anchored on the defective Ce-doped ZnIn 2 S 4 (CZ) microflowers, was synthesized by an in-situ solvothermal route, realizing exceptional CO 2 catalytic performance under simulated sunlight irradiation. According to the detailed characterizations and density functional theory calculations, the energy barrier of the rate determining step is significantly reduced due to the outstanding CO 2 adsorption and activation on rare earth Ce atoms. Simultaneously, the separation and transfer efficiency of photogenerated carriers are greatly facilitated by type-II heterojunction constructed by anchoring CdS on CZ and S vacancies resulting from a heteroatom doping strategy. Thus, the optimum photocatalyst of CZ2/C2 composite provides an advantageous platform for CO 2 photoreduction to CO, which is roughly 7.5- and 3.0-fold higher than those of the pristine ZIS and CZ2, respectively. This work offers a promising avenue for designing effective catalysts with a dual-strategy method for photocatalysis.