Construction of Heterogenous S-C-S MoS₂/SnS₂/r-GO Heterojunction for Efficient CO₂ Photoreduction

Photocatalytic reduction of CO₂ by semiconductors is of great significance in generating value-added fuels. Here, we construct a novel S-C-S heterojunction constituted of MoS₂/SnS₂/r-GO by a simple solvothermal method. The prepared MoS₂/SnS₂/r-GO showed significant photoexcitation of photosensitive oxygen (ROS) by electron spin resonance spectroscopy, demonstrating that superoxide radicals (^•O₂^-), pores, and hydroxyl radicals (^•OH) are the main active species. The constructed S-C-S heterojunction has a multilevel electron transport mechanism and synergistic effect, which provides the possibility of producing more organic fuel. The photocatalytic materials were characterized by XRD, XPS, SEM, TEM, PL, etc. As a result, the atomic layer MoS₂/SnS₂/r-GO heterojunction exhibited a CO formation rate of 68.53 μmol g^-1 h^-1 and a CH₄ formation rate of 50.55 μmol g^-1 h^-1, respectively. This work opens up new prospects for the formation of heterojunctions of chalcogenide transition-metal sulfides.