Synergetic improvement in charge carrier transport and light harvesting over ternary InVO4-g-C3N4/rGO hybrid nanocomposite for hydrogen evolution reaction

A ternary reduced graphene oxide loaded InVO₄-g-C₃N₄ nanocomposite was prepared by the wet impregnation method. The formation of InVO₄-g-C₃N₄ heterojunction and loading of rGO was corroborated by XRD, FTIR, UV–vis, TEM and XPS studies. Incorporation of both InVO₄ and rGO in g-C₃N₄ substantially increased the absorption edge of the photocatalyst from 451 nm (2.75eV) of g-C₃N₄ to 546 nm (2.27 eV) due to the formation of heterojunction. Interestingly, among the different weight % of both InVO₄ and rGO loaded g-C₃N₄, 3.0 wt% of rGO and 30 wt% of InVO₄ loaded g-C₃N₄ has shown a superior hydrogen production of 7449 μmol g⁻¹h⁻¹, a 45 times enhancement in comparison to g-C₃N₄. This can be related to the synergetic boosting of charge carrier separation at InVO₄-g-C₃N₄ heterojunction and transportation through rGO support as revealed by photoluminescence and photocurrent studies. Moreover, the hydrogen production rate obtained in the present binary nanocomposite was almost 8 times higher than the previously reported hydrogen production rate using the same binary InVO₄-g-C₃N₄ nanocomposites without rGO support.