Insights into free radical and non-radical routes regulation for water cleanup
Yi Zhou, Wenxuan Guo, Yanpan Li, Ming Gao, Xuning Li, Wenyuan Liu, Zhuan Chen, Xiaohui Zhang, Yanbo Zhou, Mingyang Xing
Abstract
In the field of wastewater treatment, the regulation of free radical and non-radical routes has been one of the major challenges. This study investigates the regulation of radical and non-radical oxidation pathways in the peroxymonosulfate (PMS) oxidation system by controlling the calcination temperature of carbon materials and constructing bimetallic single-atom catalysts (NC-FeMn(TA)). Density functional theory calculations and experimental tests indicate that increasing the pyridinic nitrogen content and incorporating single metal atoms in nitrogen-doped carbon materials result in a predominantly non-radical oxidation process. In contrast, enhancing the content of graphitic and pyrrolic nitrogen species and introducing bimetallic catalytic centers promote a radical oxidation pathway. The NC-FeMn(TA)/PMS system demonstrates high oxidation performance over a broad pH range, exhibiting significant interference resistance and stability, with 100% degradation of target pollutants after 22 cycles and complete removal of emerging pollutants (including pharmaceuticals and personal care products, endocrine disrupting chemicals, dyes and chemical materials) within 5 min. This system’s remarkable performance suggests broad application potential in water pollution control field. Controlling oxidation pathways is crucial for efficient water purification. Here, authors develop Fe/Mn single-atom catalysts that tune radical and non-radical processes, enabling rapid, robust degradation of pollutants and offering broad potential for wastewater treatment.