Core–shell morphology of Au-TiO2@graphene oxide nanocomposite exhibiting enhanced hydrogen production from water

• Core–shell Au-TiO2@graphene oxide nanocomposite displays improved photoactivity.
• A thin layer of graphene oxide exhibits better surface structural and interfacial properties.
• Superior current–voltage (I–V) characteristics of Au-TiO2@graphene oxide than Au-TiO2.
• Longer electron-hole decay time for Au-TiO2@graphene oxide than Au-TiO2 composite.
• Enhanced H2 production efficiency from water by Au-TiO2@graphene oxide.

The core–shell morphology of graphene oxide (GO) coated Au-TiO2 (Au-TiO2@GO) nanocatalysts has displayed enhanced photocatalytic activity for hydrogen production from water. The structural morphology of Au-TiO2@GO revealed a thin layer (∼2.5 nm) of GO shell over Au-TiO2 core, possessing higher specific surface area (∼100 m2 g−1). Raman spectroscopy revealed bands at 1593 cm−1 and 1317 cm−1 corresponding to G and D lines. GO facilitates decreases in the rate of e−/h+ recombination due to its reduction potential and Au loading increase sensitization of TiO2 in the visible light resulting in the increased activity for H2 production (∼114 μmol) from the water.

A thin shell of graphene oxide (GO) coated over Au-TiO2 core nanocomposite exhibited better hydrogen production efficiency from water than bare Au-TiO2 catalyst under combined UV and visible light irradiation. The lower reduction potential of GO than TiO2 facilitates the decrease in recombination rate of charge carriers whereas Au loading increases the sensitization of TiO2 in the visible light resulting in the increase of solar to hydrogen conversion efficiency as compared to TiO2 and Au-TiO2.Figure optionsDownload as PowerPoint slide