Key Laboratory of Pollution Processes and Environmental Criteria at Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Key Laboratory of Pollution Processes and Environmental Criteria at Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Sci Total Environ. 2022 Jan 1;802:149989. doi: 10.1016/j.scitotenv.2021.149989. Epub 2021 Aug 28.
Microbial fuel cells (MFCs) are promising equipment for water treatment and power generation. The catalyst used in the oxygen reduction reaction (ORR) at the cathode is a critical factor for efficacy of MFCs. Therefore, it is important to develop cost-effective cathode catalysts to enhance application of MFCs. In the current study, a novel cathode catalyst was developed, which was annealed with watermelon rind as raw material and transition metals including iron, and manganese were introduced. The 700Mn/Fe@WRC catalyst, which was annealed at 700 °C, exhibited excellent electrochemical performance. The high relative content of pyridine nitrogen caused by the inherent nitrogen element of the watermelon rind and the high content of iron and manganese elements introduced resulted in increase in electrochemical surface area to 657.6 m/g. The number of electrons transferred ORR was 3.96, indicating that ORR occurs through a four-electron pathway. The maximum power density of MFCs was 399.3 ± 7.4 mW/m with a fitting total internal resistance of 15.242 Ω, and the removal efficiency of COD was 97.1 ± 1.2%. The cost of the 700Mn/Fe@WRC catalyst was approximately 0.15 $/g, which is significantly lower compared with Pt/C (33.0 $/g). Experimental verification showed that the 700Mn/Fe@WRC prepared using the economical watermelon rind biochar (WRC) is an excellent substitute for non-precious metal catalysts used in MFCs.
微生物燃料电池（MFC）是水处理和发电的有前途的设备。阴极中氧还原反应（ORR）所用的催化剂是 MFC 效能的关键因素。因此，开发具有成本效益的阴极催化剂对于增强 MFC 的应用非常重要。在当前的研究中，开发了一种新型的阴极催化剂，它以西瓜皮为原料进行退火，并引入了铁和锰等过渡金属。在 700°C 下退火的 700Mn/Fe@WRC 催化剂表现出优异的电化学性能。西瓜皮固有的氮元素引起的吡啶氮相对高含量和引入的铁和锰元素的高含量导致电化学表面积增加到 657.6 m/g。ORR 的电子转移数为 3.96，表明 ORR 通过四电子途径发生。MFC 的最大功率密度为 399.3 ± 7.4 mW/m，拟合总内阻为 15.242 Ω，COD 的去除效率为 97.1 ± 1.2%。700Mn/Fe@WRC 催化剂的成本约为 0.15 美元/g，与 Pt/C（33.0 美元/g）相比显著降低。实验验证表明，使用经济实惠的西瓜皮生物炭（WRC）制备的 700Mn/Fe@WRC 是 MFC 中使用的非贵金属催化剂的极好替代品。
