Abstract:
Microbial fuel cells (MFCs) have emerged in recent years as a promising technology
for renewable alternative energy and wastewater treatment. MFC technology faces
numerous challenges when applied to real-world applications, which is one of the reasons
why it has yet to be widely used or commercialized despite its discovery many decades
ago. The cathodic overpotential of oxygen reduction reaction (ORR) at MFC cathodebased
carbon is a barrier to the widespread adoption of the technology. The performance
of MFCs is primarily limited by the cathode. In general, cathode performance can be
improved in two ways: by using a catalyst to lower activation energy or by increasing the
specific surface area of the cathode material. When used as a catalyst, precious metals
such as platinum catalysts reduce overpotential but increase the cost. The use of novel
and inexpensive catalysts increases ORR rates, as does the use of non-catalyzed threedimensional
carbon in cathode fabrication. The custom-made woven carbon material
used for constructing the electrodes, known as carbon microfiber material (CMM), was
sourced from Carbon Energy WT in Taiwan. Nanomaterials-modification of these CMM
electrodes was used to improve the performance of lake sediment inoculated MFCs. To
improve the ORR performance of the carbon electrode through pretreatment, a variety
of nanomaterial pretreatment methods were used. KOH, HNO3, MnO2, ZnO/NiO,
MnO2/PANI (Polyaniline), and ZnO/NiO/PANI treatments were applied to the CMM
and used as cathode electrodes; the performance was compared by plotting powercurrent
plots and polarization plots. The maximum power densities for KOH, HNO3,
MnO2, MnO2/PANI (Polyaniline), ZnO/NiO, and ZnO/NiO/PANI treatments were
51.71 mW/m2, 71.40 mW/m2, 78.54 mW/m2, 141.64 mW/m2, 67.15 mW/m2 and
129.44 mW/m2 respectively. The outcome of this study demonstrates that the nanomaterials
incorporated in carbon microfiber cathodes bring about significant enhancements
to power densities, without the usage of noble metal catalyst materials such as platinum.
