Polypyrrole/sewage sludge carbon as low-cost and high-effective catalyst for enhancing hexavalent chromium reduction and bio-power generation in dual chamber microbial fuel cells
Polypyrrole/sewage sludge carbon as low-cost and high-effective catalyst for enhancing hexavalent chromium reduction and bio-power generation in dual chamber microbial fuel cells
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DOI：
10.1016/j.seppur.2020.117805
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发表时间：
2021-02-01
影响因子：
8.6
通讯作者：
Mo, Ce-Hui
中科院分区：
文献类型：
--
作者：
Li, Meng;Zhou, Juan;Mo, Ce-Hui
微生物燃料电池作为一种潜在的生物电化学能量转换器，可以通过消耗阳极表面附着的电活性微生物从废水中提取生物能，而MFC的性能受到阴极催化剂的极大抑制。本文采用电聚合负载方法制备了聚吡咯/污泥碳电极，并将该电极用作MFC中的阴极，同时去除Cr(VI)并释放生物能。电化学分析发现聚吡咯/污泥碳电极表现出较低的电荷转移电阻和塔菲尔斜率，这表明聚吡咯/污泥碳电极具有较强的导电性和优异的电化学活性。此外，采用聚吡咯/污泥碳电极的MFC阴极室中的Cr(VI)可在30 h内被完全去除。 MFC的最大输出功率和Cr(VI)还原率分别为760.7 mW m- 2和2.16 g center dot m- 3 center dot h-3，分别是碳布电极（272.5 mW center dot m- 2和1.43 g center dot m- 3 center dot h-3）的2.79和1.51倍。此外，Cr(VI)可以被去除并以Cr(OH)3的形式沉积在电极上。聚吡咯发挥电子穿梭作用，降低MFC的内阻，增强Cr(VI)还原电极的电化学活性。因此，与污水污泥碳、聚吡咯和碳布电极相比，聚吡咯/污水污泥复合材料可以实现更稳定的Cr(VI)去除和发电，为加速Cr(VI)还原和加强生物发电提供了一种有效且低成本的催化剂。
Microbial fuel cell, a potential bio-electrochemical energy transducer can extract the bio-energy from wastewater by the consumption of the electro-active microorganism adhered the surface of anode, and the MFC performance is greatly inhibited by the cathode catalysts. Herein, polypyrrole/sewage sludge carbon electrode is fabricated by an electro-polymerization loading method and the electrode is employed as the cathode electrode in MFC for the removal of Cr(VI) and bio-energy release at the same time. The electrochemical analysis finds the polypyrrole/ sewage sludge carbon electrode exhibits the low charge transfer resistance and Tafel slope, which can demonstrate that the polypyrrole/sewage sludge carbon electrode possesses strong conductivity and excellent electrochemical activity. In addition, Cr(VI) in the cathode chamber of MFC with the polypyrrole/sewage sludge carbon electrode can be totally removed at 30 h. And the maximum output power and Cr(VI) reduction rate of MFCs are 760.7 mW m- 2 and 2.16 g center dot m- 3 center dot h-3, which are 2.79 and 1.51 times higher than those of carbon cloth electrode (272.5 mW center dot m- 2 and 1.43 g center dot m- 3 center dot h-3). Moreover, Cr(VI) can be removed and deposited on the electrode in the form of Cr(OH)3. And polypyrrole plays an electron shuttling role in reducing the internal resistance of MFC and enhancing electrochemical activity of the electrode for Cr(VI) reduction. Consequently, the polypyrrole/sewage sludge composite can achieve more stable Cr(VI) removal and power than those of sewage sludge carbon, polypyrrole, and carbon cloth electrodes, demonstrating an effective and low-cost catalyst for accelerating Cr(VI) reduction and strengthening bio-power production.