Synergistic effect of dual Z-scheme ZnO/g-C3N4/V2O5 heterogeneous nanocomposite for photocatalytic decontamination of mixed dye and pharmaceutical drug under visible light irradiation

In this study, ZnO/g-C3N4/V2O5 (ZGV) nanocomposite were constructed via facile wet impregnation method. The prepared samples were comprehensively studied by XRD, FT-IR, BET, Raman, SEM, XPS, UV-vis. absorption, PL spectroscopic and DLS analysis. From various obtained results it is confirmed that the ZnO and V2O5 nanoparticles were well dispersed on the surface of g-C3N4 nanosheets. The energy bandgap of ZGV nanocomposite was tuned from 3.18 eV to 2.06 eV, provides an improved visible light absorption ability and exhibited with immense cutdown on the photogenerated charge carrier's recombination rate. So that the ZGV photocatalyst showed remarkable degradation performance against mixed dye with 4.3 (Rh B) and 5.6 (MB) folds and tetracycline (4.8) times higher than pure and binary nanocomposite samples under visible light irradiation. The enhanced photocatalytic performance pertained by the nanocomposite was owed to the synergetic effect of heterostructure formation with efficacy charge separation along with dual Z-scheme charge transfer mechanism. Furthermore, the radicals responsive for photocatalytic activity are elucidated by free radical trapping experiment. Eventually, the prominent stability and recyclability of ZGV photocatalyst was confirmed by 5 consecutive recycle runs. The antibacterial test against Streptococcus pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Bacillus cereus were investigated. The toxicity measurement by using treated water for plant growth also revealed. Based on the results, this work suggests that the rational design and construction of heterostructure nanocomposite possess significant potential on highly efficient and reusable visible light photocatalysts for the purification of environment and energy conversion process.