Annealing effects on bio-fabricated nickel oxide nanoparticles for environmental remediation: Photocatalytic dye degradation and antimicrobial activity

Abstract

The work aims to generate highly active NiO nanoparticles (NPs) using a green method that uses Annona Reticulata leaf extract. This strategy affects the variance in annealing calefactions, hence mitigating the issue of aqua pollution. X-ray diffraction (XRD), UV–vis spectroscopy, Fourier transform infrared (FT-IR), Scanning electron microscopy (SEM), Energy dispersive X-ray (EDAX), TGDTA and adsorption–desorption isotherm are used to characterize produced NiO NPs. The phase structure as cubic of prepared specimens was observed to vary between 300 and 700 °C, according to the XRD pattern. From the UV–Vis absorbance spectra, bandgap determination of NiO NPs found in the 3.6–4 eV range. Nanoplatelets-shaped morphology with 43–47 nm particle size was determined using SEM snapshots. The destruction of organic contaminants, such as Crystal Violet (90.37 %) and Malachite green (93.33 %), was achieved in 120 min under UV light irradiation. To examine the zone of inhibition (ZOI) of the antimicrobial activity of green-produced NiO NPs against Serratia marcescens (19.2 mm), Bacillus cereus (19 mm), and Aspergillus niger (22.3 mm), experiments were conducted, and the efficiency was in the order of NiO(300 °C) > NiO(700 °C) > NiO(500 °C). There was strong photocatalytic degradation and antibacterial activity when the sample was calcined at 300 °C. Therefore, wastewater and biomedical treatment could potentially benefit from its use.