Efficient Z-scheme photocatalyst from simultaneous decoration of In2S3 nanosheets and WO3 nanorods on graphene sheets

Abstract

Inspired by natural photosynthesis, the Z-scheme photocatalyst is a promising approach to extend the absorption spectra of photocatalysts and reduce the recombination of photo-generated electrons and holes. However, the fabrication of well-structured efficient multi-component Z-scheme photocatalysts is still a big challenge. We report here a facile one-pot method to synthesize graphene-based Z-scheme photocatalysts. The one-pot method guarantees good distribution of well-structured individual components on thin-layered rGO sheets with excellent connections. With inactive WO3 nanorods and inactive β-In2S3 nanosheets attached to the surface of the rGO sheets, the synthesized In2S3/WO3/rGO tertiary nanocomposite shows excellent visible-light catalytic activity for hydrogen production at 1524 μmol g−1 h−1, demonstrating unambiguously the Z-scheme catalytic mechanism. To prevent cross-reactions and interferences, our strategy was to choose no more than one ionic precipitation reaction for the one-pot process, as unwanted cross-reactions could become inevitable if many cations and anions were present. This fabrication strategy should be applicable generally to synthesize other multiple-component nanocomposites, as demonstrated also by the preliminary results of the successful synthesis of the BiVO4/WO3/rGO nanocomposite (one ionic precipitation reaction and one hydrolysis reaction) and WO3/TiO2/rGO nanocomposite (two hydrolysis reactions).