Development of an MFC-powered BEF system with novel Fe–Mn–Mg/CF composite cathode to degrade refractory pollutants
Development of an MFC-powered BEF system with novel Fe–Mn–Mg/CF composite cathode to degrade refractory pollutants
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DOI：
10.1016/j.jclepro.2021.129348
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发表时间：
2021-10
影响因子：
11.1
通讯作者：
Weiye Wang;Qingliang Zhao;Jing Ding;Kun Wang;Junqiu Jiang
中科院分区：
文献类型：
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作者：
Weiye Wang;Qingliang Zhao;Jing Ding;Kun Wang;Junqiu Jiang
微生物燃料电池生物电芬顿（MFC-powered BEF）能原位产生并利用过氧化氢降解难降解污染物。以往的工作大多是将过渡金属负载到阴极上参与芬顿反应，表现出有限的电性能或降解性能。碱土金属（Mg 0和MgO）与过渡金属在阴极上的偶联可以改善MFC供电BEF体系的电化学性能和催化性能，这一点目前还未见报道。本研究开发了一种新型阴极材料Fe-Mn-Mg/碳纤维（Fe-Mn-Mg/CF），该材料具有良好的Mg与Fe、Mn的聚合效果，并能产生大量活性氧化物（·OH和·O2−），进一步提高了整体发电效率，增强了污染物的降解。因此，在MFC供电的BEF系统中，使用Fe-Mn-Mg/CF阴极的最大功率密度是常用的Fe-Mn/CF的2.07倍。由于表面空穴和MgO在H+吸附和电子传递方面的优势，Fe、Mn与Mg的结合促进了H2 O2和活性自由基的原位生成，从而使BEF体系对难降解污染物的催化降解性能最高。从H2 O2的产生和自由基的表征等方面探讨了反应和降解机理。总之，本研究为MFC供电的BEF系统提供了一种新的阴极制备方法，极大地提高了其电化学和催化性能。
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 (Mg0and 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 H2O2and 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 H2O2production 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.