Solar hydrogen evolution over native visible-light-driven Sn3O4

Abstract

Low-cost semiconductor photocatalysts that can efficiently harvest solar energy and generate H2 from water or alcohols will be critical to future hydrogen economies. Co-catalyst loading and/or doping of foreign element at host material have been crucial for semiconductor photocatalyst to produce significant H2 evolution, so far. We synthesized native-visible-light driven Sn3O4 photocatalyst, which significantly catalyzed hydrogen evolution from various alcohol solutions under irradiation of visible light (λ > 400 nm), without co-catalyst. The H2 production reaction proceeded through hydroxyalkyl radical reaction in the methanol solution. The apparent quantum yield was 0.4% for the Sn3O4 competitive to that of visible-light-sensitive co-catalyst loaded doped photocatalyst. The enhanced hydrogen evolution is attributed to the desirable band gap and band edge positions (CBM and VBM) of the Sn3O4 for H2 production in visible light, which would originate from atomically layered structure of Sn3O4. The Sn3O4 material is good promising photocatalyst for solar hydrogen production from alcohols.