Defected tungsten disulfide decorated CdS nanorods with covalent heterointerfaces for boosted photocatalytic H₂ generation

Owing to their intrinsic and pronounced charge carrier transport when facing the formidable challenge of inhibiting severe surface charge recombination, one-dimensional (1D) CdS nanostructures are promising for advancing high-yield hydrogen production. We herein demonstrate an efficient strategy of boosting interfacial carrier separation by heterostructuring 1D CdS with defective WS₂. This process yields solid covalent interfaces for high flux carrier transfer that differ distinctively from those reported structures with physical contacts. As a nonnoble cocatalyst, WS₂ can accept photogenerated electrons from CdS, and the sulfur vacancies existing at its edges can effectively trap electrons as active sites for H₂ evolution. Moreover, due to its strong negative property, the H⁺ from the aqueous solution can gather around WS₂. WS₂ possesses a lower reaction barrier than CdS, which expedites the kinetic process for the reaction. The optimized sample exhibits a high photocatalytic H₂ evolution rate of 183.4 µmol/h (10 mg photocatalyst), which is as far as we know among the top in the records for CdS-based photocatalysts. We believe this present work will be inspiring in addressing the interfacial charge carrier transfer by constructing covalent heterointerfaces.