MXene-Induced Construction of SnS2 Nano-Arrays with Sulfur Vacancies for High-Efficiency Photocatalytic CO2 Reduction.

Abstract

Solar-driven CO₂ reduction has gained significant attention as a sustainable approach for CO₂ utilization, enabling the selective production of fuels and chemicals. SnS₂, a non-precious metal sulfide semiconductor, has great potential in photocatalytic CO₂ reduction due to its unique physicochemical properties. However, low electrical conductivity and susceptibility to aggregation of pure SnS₂ lead to a high charge recombination rate and hinder the photocatalytic efficiency. In this study, we report that single/few-layered MXene induces ordered growth of SnS₂ through electrostatic interactions and in situ solvothermal heating. Interconnected SnS₂ nano-array with abundant sulfur vacancies was successfully prepared on MXene surface (Vs-SnS₂/MXene). This unique structure promotes the separation and migration of photogenerated charges and effectively inhibits electron-hole recombination. Compared with pure SnS₂, the average lifetime of photogenerated charges in Vs-SnS₂/MXene increased by 45.6 %. Meanwhile, its CO production rate reached 47.6 μmol⋅g^-1⋅h^-1, which was 2.6-fold higher than that of pure SnS₂ (18.3 μmol⋅g^-1⋅h^-1), and showed excellent photocatalytic CO₂ reduction performance in gas-solid-phase reaction mode. In addition, Vs-SnS₂/MXene also showed excellent stability. The results showcased the transformative potential of integration strategies for designing high-performance photocatalytic systems.