Visible-light enhanced photocatalytic performance of polypyrrole/g-C3N4 composites for water splitting to evolve H2 and pollutants degradation

In this work, we report the fabrication of polypyrrole/g-C3N4 (PPy/g-C3N4) nanocomposites via simple wet-chemical method. The photocatalytic activities of the composites are evaluated for water splitting to evolve H-2, Rhodamine B dye (RhB) and 2,4-dichlorophenol (2,4-DCP) degradation under visible-light. The results reveal that the photocatalytic performance of g-C3N4 for H-2 evolution, RhB dye and 2, 4-DCP degradation are significantly improved after coupling polypyrrole (PPy). Worth noting, the amount optimized (1 wt%PPy/g-C3N4) photocatalyst showed highest photoactivity compared to the other photocatalysts. Further, it is confirmed by means of radical trapping experiments that superoxide radical (O-2(center dot-)) is the dominant specie involved in the degradation of pollutants over PPy/g-C3N4 nano-composites. Moreover, clear photocatalytic reactions for H-2 evolution and pollutants degradation are proposed. This work would help us to deeply understand the reaction mechanism and will provide feasible routes to fabricate g-C3N4 based highly efficient photocatalysts for energy and environmental applications.