Enhanced photocatalytic activation of peroxymonosulfate by CeO2 incorporated ZnCo–layered double hydroxide toward organic pollutants removal

Abstract In this study, ceria nanosheets incorporated zinc cobalt–layered double hydroxide composites (ZnCo–LDH@CeO2) were prepared and employed as a heterogeneous photocatalyst to degrade contaminants in combination with peroxymonosulfate (PMS). The morphologies and physicochemical properties of the as–prepared photocatalysts were characterized by various technologies. The ZnCo–LDH@CeO2/PMS system exhibited the highest photocatalytic removal performance among a series of catalytic schemes with phenol (20 mg/L) as model compound and 99.8% removal was achieved after 30 min reaction under optimal conditions with 0.8 g/L PMS and 0.2 g/L catalyst at room temperature. The enhancement of more efficient separation and transportation of photogenerated electrons and holes for ZnCo–LDH@CeO2 than the two individual units was determined by transient photocurrent responses and electrochemical impedance spectroscopy instruments. The generated oxidizing species including SO4 −, OH, O2−, and h+ during the degradation process were analyzed by quenching experiments and electron paramagnetic resonance spectra, and the possible degradation mechanism was proposed. The satisfactory reusability and wide applications of ZnCo–LDH@CeO2/PMS/vis system indicated a class of promising technology for various non–biodegradable organic pollutants remediation.