Bio-electro-Fenton powered by microbial fuel cell (MFC-powered BEF) can in-situ generate and utilize hydrogen peroxide to degrade refractory pollutants. Most of the previous works loaded transition metal on the cathode to participate in the Fenton reaction showed limited electrical or degradation performance. The coupling of alkaline-earth metal (Mg⁰ and MgO) and transition metal on cathode could improve the electrochemical and catalytic properties of MFC-powered BEF system, which had not been reported so far. In this research, a novel cathode of Fe–Mn–Mg/carbon fiber (Fe–Mn–Mg/CF) was developed with good polymerization effect of Mg to Fe and Mn, and outstanding production of reactive oxide species (•OH and •O₂⁻), which further improved the overall electricity generation efficiency and enhanced the degradation of pollutants. Accordingly, the maximum power density generated in MFC-powered BEF system with Fe–Mn–Mg/CF cathode was 2.07 times higher than that of the frequently used Fe–Mn/CF. Owing to the superiority of surface holes and MgO in H⁺ adsorption and electron transfer, the integration of Fe, Mn with Mg promoted the in-situ generation of H₂O₂ and active radicals, resulting in the highest catalytic performance of degrading refractory pollutants. Initial pH, external resistance, initial concentration of contaminant and cycle use frequency of cathode were also evaluated on the degradation efficiency of the BEF system. Furthermore, reaction and degradation mechanisms were proposed from H₂O₂ production and free radical characterization. Overall, this study provided a novel cathode preparation approach for the MFC-powered BEF system, which vastly promoted its electrochemical and catalytic properties.

由微生物燃料电池驱动的生物电芬顿（MFC-powered BEF）可以原位产生和利用过氧化氢降解难降解的污染物。以前的大多数工作在阴极上加载过渡金属以参与芬顿反应，表现出有限的电或降解性能。碱土金属（Mg ⁰和MgO）和过渡金属在阴极上的偶联可以改善MFC驱动的BEF系统的电化学和催化性能，目前尚未见报道。在这项研究中，开发了一种新型的 Fe-Mn-Mg/碳纤维阴极（Fe-Mn-Mg/CF），具有良好的 Mg 对 Fe 和 Mn 的聚合效果，以及出色的活性氧化物（•OH 和 • O ₂ ^-)，进一步提高了整体发电效率，加强了污染物的降解。因此，具有 Fe-Mn-Mg/CF 阴极的 MFC 驱动的 BEF 系统产生的最大功率密度比常用的 Fe-Mn/CF 高 2.07 倍。由于表面空穴和MgO在H ⁺吸附和电子转移方面的优越性，Fe、Mn与Mg的结合促进了H ₂ O ₂和活性自由基的原位生成，从而获得了降解难降解污染物的最高催化性能.还对 BEF 系统的降解效率进行了评估，评估了阴极的初始 pH 值、外部电阻、污染物初始浓度和循环使用频率。此外，从H ₂ O _{2 的}产生和自由基表征提出了反应和降解机制。总的来说，这项研究为 MFC 驱动的 BEF 系统提供了一种新的阴极制备方法，极大地促进了其电化学和催化性能。