Fabrication of highly visible light sensitive graphite-like C3N4 hybridized with Zn0.28Cd0.72S heterjunctions photocatalyst for degradation of organic pollutants

Abstract

Novel hybridization of g-C3N4/Zn0.28Cd0.72S heterjunctions photocatalysts was successfully synthesized via the combination of chemisorptions and thermal post-treatment, wherein the g-C3N4 serves as substrates to provide sites to anchor the Zn0.28Cd0.72S nanorods. These nanostructured g-C3N4/Zn0.28Cd0.72S composites were extensively characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), ultraviolet–visible diffuse reflection spectroscopy (UV–vis-DRS) and X-ray photoelectron spectrometer (XPS). The UV–vis-DRS results revealed that absorption spectral range of hybrid composites is a monotonous enhancement with the increasing Zn0.28Cd0.72S concentration in the visible light region. Interestingly, the catalytic performance of the g-C3N4/Zn0.28Cd0.72S is strongly dependent on the loading of Zn0.28Cd0.72S. The photocatalytic results demonstrate that 70wt% g-C3N4/Zn0.28Cd0.72S hybrid photocatalyst exhibits the highest efficiency for the degradation of RhB and 4-ABA pollutants under visible light irradiation. And cycling photocatalytic tests for photocatalytic decomposition of RhB also indicate this photocatalyst is stable enough. The Fermi level (EF) and band position calculations reveal that g-C3N4 and Zn0.28Cd0.72S are well-matched overlapping band structure, which may be in favour of enhanced separation rate of holes and electrons for reason of the development of heterogeneous interface. The interfacial charge transfer process was further verified in the photoreaction system of g-C3N4/Zn0.28Cd0.72S on the basis of VB-XPS and photoluminescence spectra (PL) analysis.