Graphitic carbon nitride embedded Ni3(VO4)2/ZnCr2O4 Z-scheme photocatalyst for efficient degradation of p-chlorophenol and 5-fluorouracil, and genotoxic evaluation in Allium cepa

Abstract

Visible light photocatalysis using nano heterostructures offers an eco-friendly alternative for the removal of organic molecules. Here, we reported an enhanced photocatalytic activity of g-C3N4/Ni3(VO4)2/ZnCr2O4, a dual Z-scheme nano-heterojunction for the photocatalytic removal of p-chlorophenol (p-CP) and 5-fluorouracil (5-FU). The nano heterojunction was fabricated by a facile co-precipitation method. Initially, the fabricated nanocomposites (NCs) were characterized for Physico-chemical and optoelectronic properties, by XRD, XPS, SEM, TEM, UV–Visible DRS, BET, PL, and EIS. The fabricated g-C3N4/Ni3(VO4)2/ZnCr2O4 has shown excellent photocatalytic activity. The complete mineralization of both p-CP and 5-FU observed after 160 and 200 min of visible light irradiation respectively. The mineralization of p-CP and 5-FU was confirmed by total organic carbon (TOC) estimation and the percentage of removal TOC for p-CP and 5-FU was 99.25% and 98.9% respectively. The stability of the particle was confirmed by six cycles test. The reusable efficiency of the NCs was found to be 99.7% after six consequent cycles. The stability of the NCs was confirmed by XRD and XPS analysis of reused photocatalyst. The scavengers assay and ESR analysis confirmed the major role of •OH radicals in enhanced photocatalytic activity. The degradation pathway of p-CP and 5-FU was determined by GC–MS/MS and the possible toxicity of the intermediate compounds was determined by the ECOSAR program, which shows the non-toxic nature of the end product on green algae, daphnia, and fish. The toxicity of the NCs was tested against Allium cepa which further confirm the non-toxic nature of NCs. The study suggests that fabricated g-C3N4/Ni3(VO4)2/ZnCr2O4 NCs can be utilized for environmental remediation applications.