Tesfaye Tekalign, Shuka Yohannes, Tadesse Sisay, Eyoel Tesfahun, Mengesha Mesele
Department of Chemistry, Natural and Computational Sciences, Mettu University, P. Box 318, Illbabur, Ethiopia.
Department of Chemistry, Natural and Computational Sciences, Madda Walabu University, P. Box 247, Bale Robe, Ethiopia.
Sci Rep. 2025 Jan 2;15(1):587. doi: 10.1038/s41598-024-84311-5.
A microbial fuel cell (MFC) is a modern, environmentally friendly, and cost-effective energy conversion technology that utilizes renewable organic waste as fuel, converting stored chemical energy into usable bioelectricity in the presence of a biocatalyst. Despite advancements in MFC technology, several challenges remain in optimizing power production efficiency, particularly regarding anode materials and modifications. In this study, low-cost biosynthesized iron oxide nanoparticles (FeO NPs) were coated with a polyaniline (PANI) conducting matrix to synthesize hybrid FeO/PANI binary nanocomposites (NCs) as modified MFC anodes via an in-situ polymerization process. Characterization techniques, including UV-Vis, XRD, SEM, and FT-IR, revealed the successful synthesis of green-routed nano-scaled materials with altered optical properties after matrix coating, high crystallinity in the iron oxide phase, rougher surface morphology, and characteristic Fe-O peaks at 594 cm⁻. Additionally, the electrochemical behavior of the prepared nano-materials was characterized by cyclic voltammetry (CV), where low ΔEp values (0.473 V) for FeO/PANI NCs indicated the presence of reversible charge transfer mechanisms at the electrode surface, reflecting a high rate of electron transfer. The synthesized nanocomposite was used to modify pencil graphite anodes to construct four single-chamber MFCs: bare pencil graphite anodes, pencil graphite anodes modified with FeO, PANI, and FeO/PANI nanocomposites. The maximum open circuit voltage (OCV) value was 645 ± 24.50 mV, with a high power output of 424.51 ± 6.86 mW/m and current density of 2475.01 ± 1.23 mA m produced by the FeO/PANI NCs modified pencil graphite electrode, which is more than six times the efficiency in terms of power density compared to the unmodified pencil graphite electrode (PGE). These results demonstrate that the synthesized nanocomposite plays an effective and value-added role in modifying traditional carbon anode electrodes within an MFC energy conversion device system.
微生物燃料电池（MFC）是一种现代、环保且具有成本效益的能量转换技术，它利用可再生有机废物作为燃料，在生物催化剂存在的情况下将储存的化学能转化为可用的生物电。尽管MFC技术取得了进展，但在优化发电效率方面仍存在一些挑战，特别是在阳极材料和改性方面。在本研究中，通过原位聚合法，将低成本生物合成的氧化铁纳米颗粒（FeO NPs）包覆在聚苯胺（PANI）导电基质上，合成了混合FeO/PANI二元纳米复合材料（NCs）作为改性MFC阳极。包括紫外可见光谱、X射线衍射、扫描电子显微镜和傅里叶变换红外光谱在内的表征技术表明，成功合成了绿色路线的纳米级材料，基质包覆后光学性质发生改变，氧化铁相具有高结晶度，表面形态更粗糙，在594 cm⁻处有特征性的Fe-O峰。此外，通过循环伏安法（CV）对制备的纳米材料的电化学行为进行了表征，其中FeO/PANI NCs的低ΔEp值（0.473 V）表明电极表面存在可逆电荷转移机制，反映了高电子转移速率。合成的纳米复合材料用于修饰铅笔石墨阳极，构建了四个单室MFC：裸铅笔石墨阳极、用FeO、PANI和FeO/PANI纳米复合材料修饰的铅笔石墨阳极。最大开路电压（OCV）值为645±24.50 mV，由FeO/PANI NCs修饰的铅笔石墨电极产生的高功率输出为424.51±6.86 mW/m，电流密度为2475.01±1.23 mA m，与未修饰的铅笔石墨电极（PGE）相比，功率密度效率高出六倍多。这些结果表明，合成的纳米复合材料在MFC能量转换装置系统中对传统碳阳极电极的修饰中发挥了有效且增值的作用。
