Environmental Research Laboratory, Department of Chemistry, Faculty of Sciences, Aligarh Muslim University, Aligarh, 202002, India.
Environmental Research Laboratory, Department of Chemistry, Faculty of Sciences, Aligarh Muslim University, Aligarh, 202002, India; School of Engineering and Advanced Materials, Newcastle University, Newcastle upon Tyne, United Kingdom.
J Environ Manage. 2019 Nov 1;249:109376. doi: 10.1016/j.jenvman.2019.109376. Epub 2019 Aug 19.
Fabrication of superior and cost-effective cathodic materials is vital in manufacturing sustainable microbial electrolysis cells (MECs) for biofuels production. In the present study, a novel manganese dioxide (MnO) coated felt cathode (Mn/CF) has been developed for MECs using electrodeposition method via potentiostat. MnO is considered to encourage exogenous electron exchange and, in this way, improves the reduction of carbon dioxide (CO). MnO, as a cathodic catalyst, enhances the rate of biofuel production, electron transfer, and significantly reduces the cost of MECs. A maximum stabilized current density of 3.70 ± 0.5 mA/m was obtained in case of MnO-coated Mn/CF based MEC, which was more than double the non-coated carbon felt (CF) cathode (1.70 ± 0.5 mA/m). The dual chamber Mn/CF-MEC achieved the highest production rate of acetic acid (37.9 mmol/L) that was significantly higher (43.0%) in comparison to the non-coated CF-MEC. The cyclic voltammograms further verified the substantial enhancement in the electron transfer between the MnO coated cathode and microbes. The obtained results demonstrate that MnO interacted electrochemically with microbial cells and enhanced the extracellular electron transfer, therefore validating its potential role in biofuel production. The MnO coated CF further offered higher electrode surface area and better electron transfer efficiency, suggesting its applicability in the large-scale MECs.
制造高性能且经济实惠的阴极材料对于制造用于生物燃料生产的可持续微生物电解池（MEC）至关重要。在本研究中，通过恒电位法利用电沉积方法在 MEC 中开发了一种新型的二氧化锰（MnO）涂层毛毡阴极（Mn/CF）。MnO 被认为可以促进外源电子交换，从而提高二氧化碳（CO）的还原。MnO 作为阴极催化剂，提高了生物燃料的生产速率、电子转移效率，并显著降低了 MEC 的成本。在基于 MnO 涂层的 Mn/CF 的 MEC 中，获得了最大稳定电流密度为 3.70±0.5 mA/m，是未涂层碳毡（CF）阴极（1.70±0.5 mA/m）的两倍多。双室 Mn/CF-MEC 实现了最高的乙酸（37.9 mmol/L）生产速率，与未涂层的 CF-MEC 相比，这一速率显著提高了 43.0%。循环伏安法进一步证实了 MnO 涂层阴极和微生物之间电子转移的实质性增强。研究结果表明，MnO 与微生物细胞发生电化学相互作用，增强了细胞外电子转移，因此验证了其在生物燃料生产中的潜在作用。MnO 涂层 CF 进一步提供了更高的电极表面积和更好的电子转移效率，表明其在大规模 MEC 中的适用性。
