Designing of highly active g-C₃N₄/Ni-ZnO photocatalyst nanocomposite for the disinfection and degradation of the organic dye under sunlight radiations

An efficient photocatalytic composite Ni/ZnO/g-C₃N₄ (NiZG), has been successfully synthesized by coupling graphitic carbon nitride (g-C₃N₄) with nickel doped zinc oxide nanoparticles (Ni/ZnO NPs) via a cost-effective chemical co-precipitation method. This fabricated composite (NiZG) was meticulously characterized by FTIR, XRD, TEM, UV–vis spectroscopy, BET surface area, and transient photocurrent response. The catalytic efficiency of the (NiZG) composites was assessed by measuring the UV–vis absorption spectra of methylene blue and the bactericidal efficiency was checked against Gram-positive and Gram-negative microbes. The NiZG-70 composite (containing 3% Ni/ZnO and 70 % g-C₃N₄) demonstrated superior bactericidal and photocatalytic properties under solar radiations compared with Ni/ZnO, g-C₃N₄ alone. Photoluminescence analysis revealed that the electron-hole recombination in the composite was sufficiently reduced because of the Ni atoms functioning as electron transmitters at the interfaces. The recycling measurement of the composite signifies the extra stability of the NiZG and makes it a practical candidate for environmental remediation applications.