Self-modification of g-C3N4 with its quantum dots for enhanced photocatatytic activity

The photocatalytic activity of g-C3N4 was restricted by the fast charge recombination of photo-generated electrons and holes. In this work, a g-C3N4 metal-free composite modified with g-C3N4 quantum dots (CNQDs) (CNQDs/CN) was successfully prepared by a simple solvothermal method aiming to greatly promote the charge separation rate. The CNQDs/CN composite was confirmed by HRTEM and XPS measurements and exhibited outstanding photocatalytic activity in the degradation of organic pollutants represented by Rhodamine B. The enhanced photocatalytic performance of the CNQDs/CN composite can be ascribed to the effective charge separation and transfer across the interfaces between g-C3N4 and CNCtDs, which benefits from the excellent photoelectrochemical properties as well as the prolonged lifetime of charge carriers. The self-modification strategy provides a rational and interesting design idea to fabricate highly efficient photocatalysts.