Multichannel charge transfer mediated by polyoxometalate loaded SnS₂ wrapped Te nanostructures for efficient photocatalytic CO₂ reduction

Single-component metallic Te photocatalysts suffer from rapid oxidation in air, while sulfide-based SnS₂ is prone to photocorrosion under prolonged illumination, both severely limiting their photocatalytic efficiency. To address these challenges, we designed an S-scheme heterojunction by uniformly loading SnS₂ nanosheets onto Te nanowires (Te@SnS₂). This heterostructure not only suppresses Te oxidation but also facilitates efficient charge separation via the S-scheme mechanism. Further integration of [Co₄(H₂O)₂(PW₉O₃₄)₂]^10- (Co4POM) onto Te@SnS₂ yields the Te@SnS₂-Co4POM photocatalyst, where Co4POM serves as a hole co-catalyst to enhance activity and inhibit SnS₂ photocorrosion. The system employs two discrete charge-transfer channels, with electrons separated at the Te@SnS₂ S-scheme heterojunction and holes migrating from SnS₂ to Co4POM, thereby spatially separating reduction and oxidation sites and markedly enhancing carrier separation, catalytic activity and durability. The multi-channel charge transfer pathways enabled by Te@SnS₂-Co4POM synergize component interactions, achieving a CO production rate of 92.6 μmol g⁻¹ h⁻¹ with 97.7 % selectivity in gas-solid CO₂ reduction, alongside effective coupling of CO₂ photoreduction and water photooxidation. In situ DRIFTS, quasi-in situ XPS and irradiated KPFM studies confirm the S-scheme electron transfer in Te@SnS₂ and reveal Co4POM's role in establishing multi-channel charge transport. This work demonstrates a rational strategy to overcome stability and efficiency bottlenecks in photocatalysis through multi-component charge channel engineering. © 2025 Elsevier B.V.