Fabricated novel g-C₃N₄/Mn doped ZnO nanocomposite as highly active photocatalyst for the disinfection of pathogens and degradation of the organic pollutants from wastewater under sunlight radiations

The uncontrolled release of synthetic dyes in natural water sources and bacterial pollution has caused serious ecological and environmental threats in our daily lives. Economical and efficient materials for dye-degradation and pathogen disinfection are desperately perused for decades. The current study describes the facile fabrication of novel g-C₃N₄/Mn-ZnO nanocomposites via chemical co-precipitation approach and used, for the first time, to disinfect the polluted water and for methylene blue (MB) degradation. Surface morphology, structural analysis, elemental composition, particle size, chemical bonds, and optical properties of the prepared composites were fully investigated. Transmission electron microscopy revealed that Mn-ZnO nanoparticles (17−20 nm) were consistently disseminated on fabric like nanosheets of g-C₃N₄ to structure the hybrid g-C₃N₄/Mn-ZnO nanocomposites. A superb photocatalytic degradation of MB and excellent antibacterial competency against Gram-negative and Gram-positive bacteria under sunlight irradiation was demonstrated by the fabricated nanocomposites. The radical scavengers and electron spin resonance (ESR) experiments revealed that the superoxide and hydroxyl radicals were the leading species liable for MB deterioration. Moreover, the nanocomposites exhibited tremendous stability with a consistently high degree of MB degradation for 6 successive catalytic cycles. The superior photocatalytic activity and the perfect antimicrobial propensity of the nanocomposites were essentially endorsed to the synergic effect of the interface developed between g-C₃N₄ nanosheets and Mn-ZnO nanoparticles. The fabricated nanocomposites can be an appropriate new photocatalyst for the disinfection of pathogens and removal of organic dye from the wastewater.