Enhanced photocatalytic degradation of a hydrocortisone by biomodified and biocompatible magnetite nanoparticles and its mechanistic assessment

Every year, due to usage, overproduction, and overprescribing, a huge amount of pharmaceutical waste accumulates. Among these, hydrocortisone (a corticosteroid) has lately been popular for COVID-19 therapy. Hence, removal of these pollutants by efficient, cheaper and greener way is needed. The photocatalytic degradation of hydrocortisone by nanoparticles has yet to be investigated. In this study, the hydro-alcoholic extract of Nigella sativa seeds coated magnetite nanoparticles (NS@MNPs) was synthesized as a low-cost, sustainable photocatalyst to degrade hydrocortisone from simulated wastewater. At neutral pH, the highest degradation percentage-97.1% was achieved with 15 mg of NS@MNPs within 540 min for a 10 mL 60 mg/L of hydrocortisone solution. Experimentally, it was observed that the degradation was more specific at 254 nm irradiation. The mechanism of degradation was established by scavenging experiments, density functional theory (DFT) calculations, and liquid chromatography-mass spectroscopy analysis of the treated simulated wastewater. Due to the presence of naturally occurring ions, the degradation of hydrocortisone by NS@MNPs in the surface water was reduced. FTIR spectra after 12th cycle revealed that the coating of NS@MNPs remains unchanged, thus increasing recyclability. NS@MNPs were also proved to be nontoxic towards NIH/3T3 normal cells at micromolar concentrations, demonstrating its vast applicability.(c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.