Unveiling enhanced electron-mediated peroxymonosulfate activation for degradation of emerging organic pollutants

Abstract

The electron transfer pathway activated by peroxymonosulfate (PMS) has garnered significant attention for the removal of emerging organic pollutants from water. However, overcoming the two-step energy barriers involved in electron transport across reaction interfaces presents a formidable challenge. To surmount the two-step energy barriers of pollutant-catalyst and catalyst-PMS, a catalyst with nano-island structure was developed, forming efficient ternary catalytic interfaces with PMS and pollutants. The presence of atomic pairs within the catalyst punched through the electron transport channels, resulting in a pseudo-first-order kinetic rate of 2.06 min−1 for bisphenol A, which was 5.1 times higher than that of the control sample. The electronic coupling of atomic pairs exerted a profound impact on the splitting of d-orbitals, effectively elevating the d-orbital unoccupancy and reducing the two-step energy barriers encountered by electrons from pollutants to catalysts, and subsequently to PMS, which promoted efficient degradation of pollutants. Furthermore, through the association of two-step energy barrier, the feasibility of utilizing the orbital interaction as a descriptor of the degradation rate by electron-mediated PMS activation was demonstrated. Additionally, the intermediates generated through electron transfer pathway exhibited a lower risk of bioaccumulation. This work inspires insights into the electron-mediated mechanism of multinary catalytic interface reactions.