Efficient abatement of recalcitrant p-phenol sulfonic acid by CoFe2-xMoxO4 catalyzed peroxymonosulfate

Abstract

P-phenol sulfonic acid (PSA) is a very noxious and refractory emerging pollutant owing its chemical stability. In this study, CoFe2-xMoxO4 as heterogeneous catalysts were fabricated via a hydrothermal route and investigated as peroxymonosulfate (PMS) activator for PSA removal. X-ray diffraction (XRD), Transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) analyses indicate a well-maintained structure, suitable particle size, and larger surface area nanoparticles which offer a further active surface for the catalytic reaction. X-Ray photoelectron spectroscopies (XPS) confirm the valence and chemical structure of CoFe2-xMoxO4 with different ratios of Mo ion. CoFe2-xMoxO4/PMS degraded 88% with rate constant of 0.109 min−1 in 60 min under the reaction conditions ([PSA] = 185 mg L−1, [CoFe2-xMoxO4] = 0.3 g L−1, [PMS] = 5 g L−1, T = 20 °C, pH = 3.5). The increasing content of Mo (i.e. 0.1–1.0) in CoFe2-xMoxO4 enhanced the degradation rate, signifying that the catalytic performance was positively correlated with Mo content in the catalyst composition. The results of electron paramagnetic resonance (EPR) suggested that SO4·− and HO· radicals predominated in PMS activation by CoFe2-xMoxO4. Overall, the findings offer the applicability of such metal oxide heterogeneous catalysts for the remediation of highly recalcitrant pollutants in ambient conditions.