A rational design of g-C3N4-based ternary composite for highly efficient H2 generation and 2,4-DCP degradation.

In this work, g-C3N4 based ternary composite (CeO2/CN/NH2-MIL-101(Fe)) has been fabricated via hydrothermal and wet-chemical methods. The composite showed superior photoactivities for H2O reduction to produce H2 and 2,4-dichlorophenol (2,4-DCP) degradation. The amount of H2 evolved over the composite under visible and UV-visible irradiations is 147.4 µmol·g-1·h-1 and 556.2 µmol·g-1·h-1, respectively. Further, the photocatalyst degraded 87% of 2,4-DCP in 2 hrs under visible light irradiations. The improved photoactivities are accredited to the synergistic-effects caused by the proper band alignment with close interfacial contact of the three components that significantly promoted charge transfer and separation. The 2,4-DCP degradation over the composite is dominated by OH radical rather than h+ and O2- as investigated by scavenger trapping experiments. This is further supported by the electron para-magnetic resonance (EPR) study. This work provides new directions for the development of g-C3N4 based highly efficient ternary composite materials for clean energy generation and pollution control.