Enhancement of anodic performance toward peroxymonosulfate-based fenton-like reactions: Role of phosphorus-doping

Abstract

Phosphorus (P)-doping has gained significant attention due to its ability to enhance the catalytic activity of transition metal materials. However, the feasibility and mechanism of applying this strategy in peroxymonosulfate (PMS)-based electrochemical Fenton-like reactions (EFR) remain unclear. Herein, a novel anode (P-CFM/NF) was developed using a P-doped bimetallic (Co/Fe) metal–organic framework (MOF) and nickel foam (NF) as the precursor and substrate, respectively. Under optimal conditions, P-doping significantly improved the anodic PMS activation performance, with pollutant removal efficiency reaching almost 100 % within 60 min across a wide pH range of 3 to 11. Further investigations showed that P-doping facilitated the formation of highly reactive CoFe₂O₄, reduced electron transfer resistance (R_ct) by a factor of 5.27, and lowered the poised anodic potential, thereby enhancing the anodic performance of PMS-based EFR. Quenching experiments and electron paramagnetic resonance (EPR) tests demonstrated that the main reactive species generated during the PMS activation process induced by P-CFM/NF anode were SO₄^•−, OH^•, O₂^•− and ¹O₂. Additionally, the cathodic oxygen reduction reaction (ORR) provided another pathway for generation of O₂^•−, which served as an indispensable precursor for ¹O₂ formation. This study introduced an effective approach utilizing a P-doping strategy to enhance the catalytic activity of bimetallic MOF-derived materials in Fenton-like reactions. Furthermore, it also offers valuable insights into the advancement of organic pollutant degradation through PMS-based EFR.