Reduced Graphene Oxide/InGaZn Mixed Oxide Nanocomposite Photocatalysts for Hydrogen Production

A series of reduced graphene oxide and indium–gallium–zinc mixed oxide (RGO/IGZ) nanocomposites were successfully synthesised by a simple one‐step hydrothermal method. The as‐synthesised nanocomposites were characterised by crystallographic, microscopic, and spectroscopic methods to explore the robust photocatalytic activity of the prepared materials. XRD patterns confirmed the formation of highly pure, single‐phase, hexagonal In2Ga2ZnO7 with no impurity‐related peaks. All the photocatalysts absorbed visible light as observed from the diffuse reflectance UV/Vis spectra. The electron–hole recombination is effectively minimised by the formation of an RGO/metal oxide nanocomposite, which was successfully derived from a photoluminescence (PL) study and photoelectrochemical measurements. The decoration of IGZ nanocrystals onto reduced graphene sheets leads to significant quenching of its luminescent intensity, dramatically improved photocurrent generation (33 times more than neat IGZ) and significantly enhanced photostability. The high photocatalytic activity for H2 production is explained by the strong interaction between the IGZ nanocrystals with RGO sheets, low PL intensity, high photocurrent and large surface area. Oxides in the mix for H2 production: A series of reduced graphene oxide and indium–gallium–zinc mixed oxide (RGO/IGZ) nanocomposites is successfully synthesised by a simple one‐step hydrothermal method. Homogeneous anchoring of the indium–gallium–zinc nanocrystals on the surface of graphene significantly enhances the rate of hydrogen production under visible light.