WO₃/g-C₃N₄ composites: one-pot preparation and enhanced photocatalytic H₂ production under visible-light irradiation

Abstract

A series of WO₃/g-C₃N₄ composites with different WO₃ contents were prepared via a facile one-pot pyrolysis method, and showed notably enhanced visible-light-driven photocatalytic H₂-evolution activities, with the highest rate of 400 μmol h^-1 g_cat^-1 that was 15.0 times of that for pristine g-C₃N₄. Contents and sizes of WO₃ crystallites in the composites were easily adjusted by changing the molar ratios of (NH₄)₂WS₄ to C₃H₆N₆ in the feed reagents, thereby successfully optimizing the Z-scheme system constructed by WO₃ and g-C₃N₄ and thus effectively reducing the recombination of photogenerated charge carriers in g-C₃N₄. Moreover, pore volumes and surface areas of the composites were gradually enlarged by introducing WO₃ into g-C₃N₄ via the one-pot preparation strategy, therefore promoting the redox reactions to evolve H₂. This work presented an effective route to simultaneously optimize the phase compositions and textural structures of photocatalysts for enhanced H₂ evolution.