Efficient activation of peroxymonosulfate by 3D hollow petal‐like spherical NiCo2O4 nanomaterials for the decomposition of phenol solution: performance and mechanism

Abstract

AbstractBACKGROUNDPhenolic pollutant contamination is a serious problem. The advanced oxidation process based on sulfate radicals (SR‐AOPs) is an efficient technology for the degradation of phenolic contaminants in the aquatic environment. Bimetallic nanomaterials have attracted much attention because of their excellent catalytic performance in activating peroxymonosulfate (PMS). Herein, 3D mesoporous NiCo2O4 hollow petal spheres with a specific surface area of 252.35 m2 g−1 were successfully prepared.RESULTSIn the NiCo2O4/PMS system, phenol (50 mg L−1) was absolutely removed within 25 min with a degradation rate constant (k) of 0.19651 min−1, which is 6.2 times higher than that of the Co3O4/PMS system. The excellent catalytic activity of NiCo2O4 is attributed to the larger amount of redox cycles of Co3+/Co2+ and Ni3+/Ni2+ as well as its large specific surface area and multi‐step pore channel structure. Moreover, the related influencing factors were systematically researched in the NiCo2O4/PMS system, including reaction temperature, solution pH, initial concentration, catalyst and PMS dose, as well as matrix species (HCO3−, Cl−, NO3−, and humic acid). The recycling tests revealed the outstanding chemical stability of NiCo2O4. The electron paramagnetic resonance (EPR) and quenching experiments verify that sulfate radical (SO4• −) acts as the leading role for phenol decomposition. The possible degradation path was proposed based on the several major degradation intermediates that were detected by Gas Chromatography‐Mass Spectrometer (GC–MS).CONCLUSIONThis research provides a facile and mild method for the fabrication of promising 3D heterogeneous catalysts for PMS activation and provides a green and promising technology for effective contaminant control in modern wastewater remediation. © 2022 Society of Chemical Industry (SCI).