TiO2–rGO nanocomposites with high rGO content and luminescence quenching through green redox synthesis

•TiO2–rGO nanocomposite with 47.1 wt% rGO prepared by redox green synthesis.•TiO2 NCs size gets smaller and intercalate with rGO sheets as rGO content increases.•Light absorption increases with rGO content along with slight increase in bandgap.•rGO is exfoliated to few layers and provide low defect states for TiO2–rGO in the visible region.•High PL quenching is observed in TiO2–rGO due to long-lived electron transfer states enabling 100% photocatalytic degradation of textile dye.