摘要： A novel CQDs/TiO2 hierarchical structure with enhanced photocatalytic properties was achieved by uniformly decorating urchin-like and yolk-shell TiO2 microspheres (UYTMs) with carbon quantum dots (CQDs) through an environmentally friendly hydrothermal process. The CQDs were ?rstly synthesized by the electrochemical method, and the TEM, Raman and PL characterizations strongly indicated that the as-prepared CQDs exhibited good dispersion, high crystallinity and unique up-conversion properties. The UYTMs synthesized by a NaOH-assisted hydrothermal process showed stable 3D hierarchical structure and large surface area, which was bene?cial for light absorption and contacting with contamination. The good combination of CQDs and UYTMs was further successfully achieved during the hydrothermal process, and demonstrated by a series of tests. The photocatalytic experiments suggested that the CQDs/UYTMs exhibited better photocatalytic activities than the pure UYTMs and P25 under both visible and UV light irradiation. The CQDs/UYTMs combining with 6 wt% of CQDs showed the best photocatalytic e?ciency, while excessive CQDs tended to inhibit the photocatalytic activity. According to the results and discussions, a possible mechanism in improving the photocatalytic e?ciency of the CQDs/UYTMs is signi?cantly proposed. The up-conversion property of CQDs can broaden the absorption spectrum of CQDs/UYTMs to the visible light. Moreover, the CQDs, as the electron reservoirs, are e?cient to separate the electrons and holes, leading to an improved photocatalytic activity of CQDs/UYTMs.