Synthesis and characterization of LaCoxNi1‐xO3 perovskites as heterogeneous catalysts for phenolics degradation by persulfate activation

Abstract

AbstractBACKGROUNDDuring the last few years, perovskite materials have been widely investigated as catalysts for peroxymonosulfate (PMS) and persulfate (PS) activation in advanced oxidation processes (AOPs) for the degradation of various pollutants. In the present work, a sequence of LaCoxNi1‐xO3 (x = 0, 0.25, 0.50, 0.75, 1) perovskite materials was synthesized by sol–gel method using glycolic acid ethoxylate lauryl ether anionic surfactant as soft template.RESULTSThe physicochemical properties of the prepared materials were studied by several techniques, such as N2 porosimetry, Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR FT‐IR), X‐Ray Diffraction (XRD), X‐Ray Fluorescence (XRF), X‐Ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM). The catalytic activity towards phenolic degradation by persulfate (PS) activation was studied and, based on the reaction rate constant values, the order of increasing catalytic performance was LaCoO3 < LaCo0.75Ni0.25O3 < LaCo0.5Ni0.5O3 < LaCo0.25Ni0.75O3 < LaNiO3. The perovskites that exhibited optimal catalytic activity (i.e., LaCo0.25Ni0.75O3 and LaNiO3) were further evaluated for their stability, reusability, and catalytic mechanism. Finally, according to scavenging experiments, 1O2, SO4•‐, and •OH generated with 1O2 played the dominant role in phenolic degradation.CONCLUSIONThe substitution of Co by Ni in LaCoO3 materials showed an increase in their catalytic activity towards phenolic oxidation through persulfate activation. The results provide insights into the characterization and mechanisms of novel perovskite catalysts and their applications for the removal of organic pollutants by advanced oxidation processes (AOPs). Further studies improving the stability and reusability of the catalysts should be conducted. © 2022 Society of Chemical Industry (SCI).