Facile preparation of a TiO2 quantum dot/graphitic carbon nitride heterojunction with highly efficient photocatalytic activity

In this article, mechanical grinding, an effortless and super-effective synthetic strategy, is used to successfully synthesize a TiO2 quantum dot (TiO2QD)/graphitic carbon nitride (g-C3N4) heterostructure. X-ray photoelectron spectroscopy results together with transmission electron microscopy reveal the formation of the TiO2QD/g-C3N4 heterostructure with strong interfacial interaction. Because of the advantages of this characteristic, the prepared heterostructure exhibits excellent properties for photocatalytic wastewater treatment. Notably, the optimum photocatalytic activity of the TiO2QD/g-C3N4 heterostructure is nearly 3.4 times higher than that of the g-C3N4 nanosheets used for the photodegradation of rhodamine B pollutant. In addition, the stability and possible degradation mechanism of the TiO2QD/g-C3N4 heterojunction are studied in detail. This method may stimulate an effective approach to synthesizing QD-sensitized semiconductor materials and facilitate their application in environmental protection.