Reverse Electron Transfer-Induced SnS2 Phase Transition for Efficient Photocatalytic CO2–C2H6 Conversion

Two-dimensional metal sulfides such as SnS 2 play a pivotal role in the field of environmental energy due to their suitable optical bandgap and high specific surface area. However, the steady-state 2H-phase SnS 2 suffers from rapid charge recombination and low CO 2 catalytic activity, limiting its practical application in photocatalytic CO 2 reduction. In this work, we designed a CuPd/SnS 2 heterojunction system by loading CuPd nanoparticles onto SnS 2 nanosheets (NSs). Under illumination, the hot electrons excited in CuPd nanoparticles induce a 2H-1T-phase transition of SnS 2, effectively improving the photogenerated carrier dynamics of the material. Additionally, the post-transition energy level structure facilitates more efficient injection of photogenerated electrons into highly catalytic CuPd particles, achieving the goal of photocatalytic reduction of CO 2 to C 2 H 6 . Resultingly, the CuPd/SnS 2 photocatalytic system achieves a C 2 H 6 production rate of 255.6 μmol g –1 h –1, which is approximately 24.4 times and 3.9 times higher than that of Cu/SnS 2 and Pd/SnS 2, respectively. Moreover, it boasts a remarkable product selectivity of up to 90.4% for C 2 H 6 . This study provides a valuable approach for modulating photogenerated carrier dynamics and enhancing catalytic activity in two-dimensional metal sulfides.