Dopping-elements electronegativity-guided electronic modulation of N, P doped carbon coated CoFeP: Dual-functional contaminant degradation via electrooxidation and PMS (Peroxymonosulfate) activation

Doping engineering is regarded as critical strategy for modulating the electronic structure of transition metal phosphides (TMPs) to regulate the properties of surface-coated carbon in catalysis-based contaminant removal. However, the correlation between dopant characteristics and the catalytic behavior of system remains rarely explored. Herein, several elements (Mn, Cu and Ni), which are in the same period as Fe/Co with varying electronegativity, is doped iron cobalt phosphide (CoFeP) in N, P co-doped carbon-coated doped-CoFeP (M−CoFeP@NPC) for dual-functional contaminant degradation. The Cu with slightly higher electronegativity than Co/Fe doped electrocatalyst (Cu-CoFeP@NPC)) exhibits optimal physical&chemical properties and electrochemical behaviour than that of Ni-CoFeP@NPC and Mn-CoFeP@NPC. Density function theory (DFT) calculations demonstrate that charge rearrangement, charge transfer process and adsorption/desorption of water dissociate intermediates of M−CoFeP@NPC exhibit a volcano-shaped trend with increasing electronegativity of doping elements, especially Cu-CoFeP@NPC significantly outperforms other counterparts. Of note, Cu-CoFeP@NPC presents outstanding electrochemical durability, superior mineralization efficiency, and broad adaptability, achieving nearly 100 % tetracycline hydrochloride (TCH) degradation within 60 min while maintaining reusability. Encouragingly, M−CoFeP@NPC also can achieve efficient contaminants degradation via PMS activation, which is owing to formation of localized electron-rich regions and accelerated charge transfer. This study offers new horizons for expanding the application of doped-elements electronegativity-guided TMPs@carbon-based catalyst for advanced contaminant remediation.