Electro-induced activation of persulfate over N-doped porous carbon decorated with Fe/Ni bimetals for organic pollutants enhanced degradation: Synergism of electro-activation and catalytic activation

The booming demand for modern medicine has led to the widespread occurrence of antibiotics in aquatic environments. The co-activation of persulfate (PS) by electrochemical and catalytic processes has now drawn increasing interests for the treatment of refractory contaminants in water. Herein, N-doped porous carbon decorated with Fe/Ni bimetallic composite catalyst (FeNi-NC) was prepared with Fe-doped Ni-MOFs as a precursor. The composite catalyst was evaluated for it performance to catalyze PS in the presence of an electric field for the destruction of tetracycline (TC). Thanks to the synergistic effect between the electrochemical and Fe1Ni5-NC-600 catalytic processes to activate PS, the E-Fe1Ni5-NC-600 system exhibited a satisfactory performance for TC degradation, attaining a 91.94 % removal within 90 min. Electric field accelerated the redox cycles of Fe0/Fe2+/Fe3+ and Ni0/Ni2+/Ni3+ to realize the sustainable catalytic activation of PS to form reactive species (OH, SO4−, and 1O2) for enhanced TC degradation. Competition kinetics studies suggested OH was the dominant reactive species, and electron-transfer process also contributed to TC removal. Moreover, the E-Fe1Ni5-NC-600/PS system exhibited a low energy consumption (0.34 kWh/m3-log), wide effectiveness in the elimination of on different organic pollutants, and good applicability for real water treatment. This study provided new insights into the application of PS-based advanced oxidation process for the high-performance treatment of antibiotic-containing wastewater.