Carbon quantum dots modified oxygen doped carbon nitride nanosheets with enhanced hydrogen evolution under visible light irradiation

Abstract The development of catalysts with strong broad-spectrum absorption for visible light hydrolysis to generate H2 has been becoming an important research fields for clean energy conversation. In this work, a in-situ two-step thermal polymerization method was used to introduce carbon quantum dots (CQDs) into oxygen doped graphitic carbon nitride (CNO) to obtain modified products CNOC with different content of CQDs. The as prepared samples were characterized by XRD, TEM, BET, PL, Electrochemical experiments and so on and photocatalytic H2 production from water was used to evaluate the performance of the catalyst. Relative to CNO, the porosity and specific surface areas of CNOC-1.0 significantly increased; the visible light absorption range was extended, and the separation efficiency of photo-generated charge carriers was improved. As a result, CNOC-1.0 decorated with 1.0 wt. % of CQDs shows the best photocatalytic activity. The corresponding H2 evolution rate (HER) is 316.6 μmol•h−1, which is 2.1 times of CNO nanosheets (154.5 μmol•h−1).