Coordination dependent photocatalytic peroxymonosulfate activation on biomass derived Fe single atom catalysts for atrazine degradation
Xue Liu, Jiguang Zhang, Jiguang Zhang, Shuaijun Wang, Shuaijun Wang, Yuan Yuan, Weisong Yu, Fang Song, Fanyu Kong, Jun Qiu, Shaobin Wang, Shaobin Wang, Jinqiang Zhang, Jinqiang Zhang
Abstract
• Biomass derived Fe SACs with varying Fe–N x coordination were synthesized. • Fe–N 6 sites facilitated efficient electron transfer from the CN support to PMS. • Fe–N 6 sites demonstrated high selectivity for 1 O 2 formation. • SA-FeN 6 /CN system achieved over 80 % ATZ degradation in just 15 min. • Three potential degradation pathways, comprising 12 products, were proposed. Challenges associated with uncontrollable metal coordination structures in biomass-derived single-atom catalysts (SACs) and their intricate impacts on photocatalytic peroxymonosulfate (PMS) activation pose significant hurdles for the application of photo-Fenton technology towards wastewater treatment. Herein, we employed a co-pyrolysis strategy using Enteromorpha prolifera ( E. prolifera ) to synthesize Fe SACs with varying Fe–N X coordination, i.e., Fe–N 5 and Fe–N 6 . Fe–N 6 -based SAC achieved over 80 % atrazine (ATZ) degradation in 15 min, with a degradation rate of 0.13 min −1 , representing 2.6-fold improvement over SAC with Fe–N 5 structure. Experimental and simulation results revealed that Fe–N 6 active sites acted as electron donors, enhancing the delocalization of π-electrons and improving photocatalytic PMS activation. This SAC also exhibited high selectivity for 1 O 2 degradation pathway and impressive ATZ degradation in seawater, with notable chlorine resistance, underscoring its potential in environmental pollutant remediation. This work unveils the catalyst structure-photocatalytic PMS activation performance relationship, offering avenue for developing more sustainable and efficient biomass-derived SACs for wastewater treatment.