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[Display omitted] • Composite photocatalyst formed between graphitic carbon dots (GCD) and TiO 2. • Ligand-to-metal charge transfer (LMCT) in TiO 2 /GCD broadens photoactive region. • Electron transfer from GCD to TiO 2 CB via LMCT crucial for photocatalysis. • TiO 2 /GCD robust and reusable under visible light irradiation in aqueous systems. • H 2 O 2 generation and pollutant degradation on irradiation from 320 to 800 nm. In recent decades, solar-to-chemical conversion catalysts for energy and environmental applications have drawn significant attention. Catalysts composed of nano-size TiO 2 and various dye-based photosensitizers can absorb solar light efficiently and produce promising photocatalysts, but their photoactive region is limited. In this study, we demonstrate that nanocomposites composed of graphite-derived carbon dots (GCDs) and TiO 2 are capable of ligand-to-metal charge transfer (LMCT), which was active across the entire visible-light spectrum. The effect of GCDs on the photocatalytic activity of TiO 2 was determined through the production of hydrogen peroxide and the degradation of pollutants. On the basis of chemical and optical investigation, we demonstrate the formation of an LMCT band in the TiO 2 /GCD nanocomposites, which are responsible for photoactivation below the bandgap of each component. Our research provides conclusive evidence for the presence of the LMCT band in TiO 2 /GCD and reveals a novel method for expanding the light-absorption spectrum of the photocatalyst. [ABSTRACT FROM AUTHOR]