Enhanced Selectivity in PMS Activation via Non-Metal Doping for Efficient 1O2 Generation in Emerging Organic Pollutants Degradation

Abstract

The activation of peroxymonosulfate (PMS) to generate singlet oxygen (¹O₂) for the removal of emerging organic pollutants (EOPs) from complex aqueous environments has garnered widespread attention. However, the low efficiency and selectivity of current PMS activation for ¹O₂ generation result in suboptimal EOP degradation. To enhance the selectivity of PMS activation and promote the non-radical pathway, non-metal heteroatoms with varying electronegativities were introduced to disrupt the symmetrical coordination structure of Fe active sites in Fe single-atom catalysts. The results showed that, in the B-Fe₁/GLCNs/PMS system, the pseudo-first-order kinetic rate for bisphenol A (BPA) degradation reached 4.435 min^–1, which is 7.4 times higher than that of the unmodified control group. Experimental and theoretical calculations demonstrated that the doping of non-metal heteroatoms altered the electron density and distribution at the Fe active sites, thereby modulating the adsorption configuration of HSO₅^– and increasing the selectivity for PMS activation to generate ¹O₂. Additionally, the degradation of EOPs by ¹O₂ produced intermediate products with lower biological toxicity, and ¹O₂ demonstrated strong anti-interference capability. The change in HSO₅^– morphology improved the rate of ¹O₂ generation. This study provides deep insights into designing high-performance PMS activation catalysts via non-metal doping to regulate the electronic structure of active sites for a selective non-radical pathway.