Dye-cosensitized graphene/Pt photocatalyst for high efficient visible light hydrogen evolution

In this work, a highly efficient and stable photocatalytic H2 evolution catalyst was constructed on Pt deposited graphene sheets cosensitized by Eosin Y (EY) and Rose Bengal (RB). Under two-beam monochromic light irradiation (520 and 550 nm), a high quantum yield (QY) up to 37.3% has been achieved owing to maximum utilization of incident visible light. As a result of the excellent electron transport properties of graphene, it can greatly facilitate the forward electron transfer from photoexcited dye molecules to Pt catalyst and suppress back electron transfer, which significantly enhances photocatalytic efficiency for H2 evolution. This efficient cosensitization strategy is also effective in enhancing H2 evolution efficiencies of dye sensitized TiO2 and multiwall carbon nanotubes (MWCNTs).

► A high efficient photocatalyst for H2 evolution was constructed.
► Graphene/Pt cosensitized by Eosin Y (EY) and Rose Bengal (RB).
► Under visible light irradiation, a quantum yield of 37.3% has been obtained.
► Graphene facilitates the electron transfer from photoexcited dye to Pt catalyst.
► Graphene suppresses the back electron transfer and enhances efficiency.