Enhanced Peroxymonosulfate Activation by NixCo1−xOOH for Efficient Catalytic Oxidation of Organic Pollutants

Peroxymonosulfate(PMS) has received increasing attention as viable technology for recalcitrant organics removal from polluted waters. Although promising, alternative heterogeneous catalysts with stable structure, strong hydrophilicity, environmental friendliness and excellent catalytic performance are highly desirable to facilitate the wide industrialization of PMS. In this work, Ni doped CoOOH catalyst was employed as PMS activator. Ni dopant had a significant influence on the morphology, structure and catalytic performance of CoOOH, Ni 0.2 Co 0.8 OOH exhibited the best catalytic performance. Reaction rate of Ni 0.2 Co 0.8 OOH was 2, 4, and 4.4 times that of CoOOH, CoFe 2 O 4 and Co 3 O 4 , respectively. Moreover, Ni 0.2 Co 0.8 OOH/PMS system had potential application to organic pollutants and displayed a great catalytic activity over a broader pH value( e.g. , 4–10). More importantly, Ni doping accelerated the transformation of Co(III) and Co(II) and formed active species CoOH + and NiOH + , which were responsible to the enhancement of PMS activation. • OH, S O 4 ∙ − , O 2 ∙ − and 1 O 2 were detected, indicating both non-radical and radical processes in the Ni 0.2 Co 0.8 OOH/PMS system. These findings provide a promising alternative to mixed-metal oxyhydroxides catalysts for PMS activation, demonstrating a great potential in environmental remediation and wastewater treatment.