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

Abstract

• The 2D rGO/SnS 2 /Ag nanostructure can split pure water into H 2 and O 2 under visible light without any sacrificial reagent. • rGO nanosheets is combined with ultrathin SnS 2 nanoplates by C-S bond. • Ag nanoparticles serve as electrons collector in a co-catalytic fashion. • rGO nanosheets works as an electron shuttling mediator to extract the photoinduced holes. Photocatalytic overall splitting of pure water producing H 2 and O 2 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/SnS 2 /Ag nanostructure photocatalyst which can split water into H 2 and O 2 without any sacrificial reagent. Specially, rGO nanosheets which is combined with ultrathin SnS 2 nanoplates by C-S bond works as an electron shuttling mediator to extract the photoinduced holes. Ag nanoparticles induce electrons injection from SnS 2 to Ag’s surface in a co-catalytic fashion. Additionally, a theoretical study reveals that appropriate charge density distribution of rGO/SnS 2 /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/SnS 2 /Ag nanostructure exhibits production rates of H 2 and O 2 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.