Preparation of heterostructure g-C3N4/ZnO nanorods for high photocatalytic activity on different pollutants (MB, RhB, Cr(VI) and eosin)

Abstract The g-C3N4/ZnO nanorods were prepared by simple hydrothermal, grinding and calcination methods. The characterization of g-C3N4/ZnO nanorods was done by different analytical techniques such as SEM, TEM, XRD, XPS, FT-IR and UV–Vis. g-C3N4/ZnO nanorods with heterostructures have been successfully synthesized without changing the structure between the monomers, which broadens the visible light response range and improves several major pollutants in water degradation rate. Photocatalytic studies were done for the degradation of MB, RhB, Cr(VI) and eosin which are almost fully degraded. The experimental results show that the photocatalytic performance of the nanorods is much better than others. The g-C3N4/ZnO photocatalyst has excellent stability and repeated cycle performance. Basing on the results of comprehensive free radical trapping test and ESR tests, it is proposed that the main active substance of the catalyst for degrading dyes is ·02-, and ·OH played significant roles in the degradation process. A good photocatalytic mechanism has been proven.