Cu doped Fe2O3 growing a nickel foam for sulfadiazine degradation in peroxymonosulfate assisting photo-electrochemical system: Performance, mechanism and degradation pathway

In this study, cost-effective and easily recovery Cu doped Fe2O3 in-situ growing on a nickel foam (Cu-Fe2O3/NF) was successfully fabricated and employed in peroxymonosulfate (PMS) assisting visible-light photoelectrochemical oxidation (VL + EC + catalyst + PMS) system for sulfadiazine (SD) removal. The optimum 2Cu-Fe2O3/NF exhibited excellent catalytic efficiency toward SD degradation in the VL + EC + catalyst + PMS system, 100% of SD being removed in 10 min and the firs-order reaction kinetic constant being 41.30 × 10-2 min−1. The excellent catalytic efficiency of 2Cu-Fe2O3/NF was due to the depressed recombination of photoinduced electron and hole, the enhanced electron transfer efficiency, more Fe2+, Cu+ and Ni2+ in sample resulting from Cu doping, and more active sites owing to the bulk thick petals-like of Fe2O3 being changed to thinner flakes after Cu doping. Therefore, a large number of reactive oxygen species including •OH, •O2− and h+ in the VL + EC + 2Cu-Fe2O3/NF + PMS system were produced to degrade SD. The mechanism of SD degradation in the system was explored in detail. The 2Cu-Fe2O3/NF displayed adaptation ability for a wide range, good anti-interference ability toward ions in real water. More inspiring, benefiting from the in-situ growth of Cu-Fe2O3 on NF surface, 2Cu-Fe2O3/NF exhibited good durability and recycle ability. This study provides a worthy reference for designing efficient and easily recycled catalysts and promotes the practical application possibility of low-cost Fe2O3 in antibiotics removal.