Amen Mohamed Taha, Kim Hak Yong, Barakat Nasser A M
Department of Nano Convergence Engineering, Jeonbuk National University Jeonju 54896 Republic of South Korea
Microbiology Department, Faculty of Agriculture, Zagazig University Zagazig 44511 Egypt.
RSC Adv. 2022 May 23;12(24):15486-15492. doi: 10.1039/d2ra00591c. eCollection 2022 May 17.
It is agreed that low mass transfer and poor reaction kinetics are the main reasons behind the low power density of microbial fuel cells (MFCs). Microscale MFCs can introduce a marvelous solution for the mass transfer dilemma. However, the volumetric power density and coulombic efficiency of present microscale MFCs are still limited due to the poor reaction kinetics. The size, shape, chemical properties and material of the electrodes are essential parameters controlling the reaction kinetics. In this study, a 3D carbon nanofiber disk is introduced as an effective anode for a single-chamber air-cathode micro-sized MFC as it improved the reaction kinetics. The proposed electrode was fabricated by a judicious combination of the electrospinning technique and thermal treatment. Owing to the intercalation of the microorganisms in the carbon nanofiber skeleton, compared to many previous reports, high power and current densities of 8.1 Wm and 44.9 Am, respectively, were obtained from the 19.6 μL single-chamber air-cathode MFC. However, the thickness of the carbon nanofiber layer has to be optimized by adjusting the electrospinning time. The power density observed from a 10 min electrospinning time-based anode outperformed the 5- and 20 min ones by 1.5 and 2 times, respectively.
人们一致认为，传质效率低和反应动力学不佳是微生物燃料电池（MFC）功率密度低的主要原因。微型MFC可为传质难题引入绝妙的解决方案。然而，由于反应动力学不佳，目前微型MFC的体积功率密度和库仑效率仍然有限。电极的尺寸、形状、化学性质和材料是控制反应动力学的关键参数。在本研究中，引入了一种三维碳纳米纤维圆盘作为单室空气阴极微型MFC的有效阳极，因为它改善了反应动力学。所提出的电极是通过静电纺丝技术和热处理的明智组合制造的。由于微生物嵌入碳纳米纤维骨架中，与许多先前的报道相比，从19.6 μL单室空气阴极MFC分别获得了8.1 W/m³和44.9 A/m²的高功率和电流密度。然而，碳纳米纤维层的厚度必须通过调整静电纺丝时间来优化。基于10分钟静电纺丝时间的阳极观察到的功率密度分别比5分钟和20分钟的阳极高出1.5倍和2倍。
