Engineering a 1D/1D WO₃/FeWO₄ S-scheme heterostructure for enhanced photocatalytic hydrogen evolution

Maximizing the spatial separation of photogenerated charge carriers while maintaining their strong redox potential remains the primary challenge in sustainable solar driven hydrogen production. In this study, a novel 1D/1D WO₃/FeWO₄ S-scheme heterostructure was synthesized via a facile two-step hydrothermal method. The morphological characterization studies confirm that 1D FeWO₄ nanowires are tightly anchored onto 1D WO₃ nanorods, forming a layered architecture that exposes abundant active sites and establishes continuous longitudinal charge transfer channels. Therefore, the optimized WO₃/FeWO₄ heterostructure exhibits a photocatalytic hydrogen evolution rate of 1602 µmol g^-1 h^-1, representing an approximately 3.6-fold enhancement compared to pristine FeWO₄, while pristine WO₃ demonstrates negligible activity. Density functional theory calculations combined with surface analysis suggest that the intrinsic work function difference between WO₃ and FeWO₄ promotes spontaneous interface electron redistribution. This creates a strong internal electric field that is proposed to facilitate the S-scheme charge transfer pathway under illumination, thereby suppressing photocarriers with weak redox ability while retaining the strongly reducing electrons on FeWO₄. This work provides a viable approach for combining dimensional engineering with interfacial electric field modulation to construct efficient S-scheme photocatalysts.