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

Abstract

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, Ni0.2Co0.8OOH exhibited the best catalytic performance. Reaction rate of Ni0.2Co0.8OOH was 2, 4, and 4.4 times that of CoOOH, CoFe2O4 and Co3O4, respectively. Moreover, Ni0.2Co0.8OOH/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, $$\overline G $$ and 1O2 were detected, indicating both non-radical and radical processes in the Ni0.2Co0.8OOH/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.