LAUSR

Abstract In this work, the oxygen vacancy-rich SnO 2 quantum dots (QDs) have been synthesized via facile vapor hydrolysis method and employed as an efficient visible-light photocatalyst for MO degradation. The as-prepared oxygen vacancy-rich SnO 2 QDs showed ultrahigh visible light photocatalytic activity for MO degradation (k = 1.1699 min -1 ), which was about 182.13 and 259.26 times as high as that of P25 TiO 2 (k = 0.00642 min -1 ) and commercial SnO 2 (k = 0.00451 min -1 ). Besides, the SnO 2 QDs-160 photocatalyst had a bandgap of 2.29 eV, much narrower than that of commercial SnO 2 (˜3.56 eV), mainly because of the formation of oxygen vacancy defects in the SnO 2 QDs. The photocatalytic MO degradation under visible-light irradiation here was mainly attributed to the oxidation of the superoxide radicals and holes. This work also indicated that the as-prepared SnO 2 QDs could serve as a promising visible-light photocatalyst for efficient environmental photocatalysis.