Role of electronic properties in partition of radical and nonradical processes of carbocatalysis toward peroxymonosulfate activation

Abstract

Nanocarbon-catalyzed advanced oxidation processes for wastewater remediation are green and state-of-the-art methods, nevertheless, the origins of carbocatalysis remain unresolved. In this study, carbon nanotubes (CNTs) are employed as typical metal-free catalysts for catalytic peroxymonosulfate (PMS) activation and phenol oxidation. The surface chemistry and electronic properties of CNTs are deliberately tailored by liquid acid oxidation and subsequent thermal treatment. It is unveiled that the electron-rich carbon surface and carbonyl groups can affect organic adsorption capacity of the carbocatalysts and modulate persulfate activation in different catalytic manners. Furthermore, the relationship between the surface chemistry (oxygen functionality and electron density) and carbocatalysis is established, which is decisive to regulate the radical/nonradical pathways in the catalytic oxidation for water purification. This study provides new insights to carbon-catalyzed persulfate activation with manipulated reaction pathways and redox potentials.