Co-TiO2 supported on reduced graphene oxide as a highly active and stable photocatalyst for hydrogen generation

We have developed a highly active and stable catalyst based on Co and TiO2 nanoparticles anchored on reduced graphene oxide (rGO) sheets for the photocatalytic hydrogen generation from water splitting. The catalyst was prepared using a novel methodology involving the modified Hummers approach followed by pyrolysis. The crystallinities, morphologies, optical properties, and chemical structures of the synthesized catalysts were investigated using different characterization techniques. The photocatalytic activity was investigated under UV-vis spectroscopy in solutions containing different Na2S + Na2SO3 concentrations and methanol as hole scavengers. The optimized composite that comprises Co: TiO2:rGO (1:6:10) shows a 2.5-fold improvement in the catalyst efficiency under UV-vis compared to bare TiO2, and it was recycled with the same activity for three cycles. This remarkable improvement in the photocatalytic activity of the developed nanocomposites compared to TiO2 can be attributed to the improved capacity of the nanocomposites to absorb visible light and efficiently separate charge carriers at the interface.