Carbon nitride quantum dots‐modified cobalt phosphate for enhanced photocatalytic H2 evolution

Abstract

AbstractIn the present work, carbon nitride quantum dots (CNQDs)‐modified cobalt phosphate (CoPi) composites CNQDs/CoPi‐x (x = 1, 2, 3) were prepared at room temperature and characterized by FTIR, XRD, UV–Vis DRS, EIS, SEM, TEM/HR‐TEM, XPS, and N2 gas adsorption. The morphologies and surface areas of CNQDs/CoPi‐x have no remarkable change after modification of CNQDs, compared with pure CoPi. The obtained CNQDs/CoPi‐x shows enhanced activity and stability of photocatalytic H2 evolution compared to pure CoPi using Eosin Y (EY) as a sensitizer and triethanolamine as an electron donor. The CNQDs/CoPi‐2 possesses the highest hydrogen evolution rate, 234.5 μmol h−1 g−1, upon visible light, which outshines that of CoPi by 2.4 times. It was believed that the enhanced photocatalytic performances of the CNQDs/CoPi‐2 could result from the boosted electron transfer from radical EY·− to CNQDs/CoPi‐2 by the employment of CNQDs; in addition, the visible‐light activity of CNQDs contributes to hydrogen evolution. The mechanism of photocatalytic hydrogen production was discussed. This study may contribute toward the development of production of “green hydrogen” using solar.