Carbon based-nanomaterials used in biofuel cells – A review

In the past several years, biological fuel cells (BFCs) have become an explorable technology that attained the status of current research activities amongst researchers working on energy crises throughout the world. The BFCs have various applications such as wearable and implantable biomedical devices, self-powered biosensors and wastewater treatment. But the employment of BFCs are still challenging due to their long-term operational stability and low power output. Majority of the BFCs constructed so far are able to power short-term bioelectronic devices. This review article presents the subsets of fuel cells, focusing on enzyme-based biofuel cells (EFCs) utilizing different nanomaterials. The nanomaterials-based EFCs are extensively studied to elaborate the benefits of the employment of the nanomaterial in the enhancement of efficiency of EFCs. Generally, it is hard to attain effective transfer of electron on a flat electrode structure from enzymes as a result of its nonspecific orientation at the electrode surface. Various nanomaterials were used effectively to bridge the gap between redox-active centers inside the enzyme and electrodes surface for better electron transfer. Significant advancements have been achieved in EFCs by employing carbon-based nanomaterials, namely, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon nanoparticles, quantum dots, graphene, and hybrid carbon nanomaterials. Even though the enhancement in the performance of EFCs is still a significant challenge. However, the adoption of carbon-based nanomaterials for the construction of EFCs has been considered a promising and practical approach to achieve high energy generation.