Construction of Ag decorated 2D rGO/SnS2 nanostructure towards synergistically enabling overall water splitting

Abstract Photocatalytic overall splitting of pure water producing H2 and O2 is a promising route to achieve the effective utilization of solar energy. However, a major drawback of low carrier separation efficiency restrains the development of photocatalysts. Here we design and fabricate an efficient 2D rGO/SnS2/Ag nanostructure photocatalyst which can split water into H2 and O2 without any sacrificial reagent. Specially, rGO nanosheets which is combined with ultrathin SnS2 nanoplates by C-S bond works as an electron shuttling mediator to extract the photoinduced holes. Ag nanoparticles induce electrons injection from SnS2 to Ag’s surface in a co-catalytic fashion. Additionally, a theoretical study reveals that appropriate charge density distribution of rGO/SnS2/Ag and the lower work function of rGO synergistically realize the higher separation efficiency of photogenerated carriers and higher quantum yield. As a result, the rGO/SnS2/Ag nanostructure exhibits production rates of H2 and O2 as high as 137 and 68 μmol h-1 g-1 under visible-light irradiation. This work may provide valuable guides in rationally designing new efficient photocatalysts for splitting pure water.