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

Abstract

Maximizing the spatial separation of photogenerated charge carriers while maintaining their strong redox potential remains the primary challenge for 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 characterizations 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.