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

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.