Enhanced photocatalytic degradation of water pollutants using bio-green synthesis of zinc oxide nanoparticles (ZnO NPs)

Abstract

Chemical pollutants released from textile industries are becoming a major concern for water pollution, causing hazardous diseases around the globe. Strategies developed against the treatment of effluents from textile industries are becoming a mere failure. Therefore, metal oxide nanoparticles (MO NPs) came into rescue as an alternative to the already available dye treatment techniques. So far, numerous research data have been published on the applications of MO NPs in antimicrobial and anticancer applications, photocatalysis, and wastewater treatment. In recent trends, Zinc Oxide nanoparticles (ZnO NPs) have been reported to possess strong photocatalytic properties depending upon the sources of energy, UV irradiation and surface hydroxyl radicals. The biological synthesis route has provided a better, safer, and efficient way of fabricating ZnO NPs for bioremediation purposes. The present study is the first and foremost report on the synthesis of ZnO NPs using Ruellia tuberosa for antimicrobial and bioremediation purposes. The physical and chemical compositions of ZnO NPs analysed using UV–Vis spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), Energy dispersive X-ray spectroscopy (EDAX), and Transmission electron microscopy (TEM) revealed rod shaped NPs with a size of 40–50 nm. ZnO NPs exhibited higher antibacterial activity against Gram negative bacteria, especially Escherichia coli. Further, textile fabrics were coated with ZnO NPs to prevent the growth of Escherichia coli. In an environmental perspective, ZnO NPs degraded 94% and 92% of methylene blue (MB) and malachite green (MG), respectively. Thus, the present study will give a brief idea on the application of ZnO NPs in the textile industry for the degradation of synthetic dyes and inhibition of pathogenic bacteria. The present study is novel, simple, compatible and hence, can be utilized for future biomedical and environmental applications.