Engineered nanomaterials in microbial fuel cells – recent developments, sustainability aspects, and future outlook

Microbial fuel cells (MFCs) have recently emerged as green technology for the direct electricity generation from polluted (waste)water loaded with organic and inorganic contaminants. Despite the remarkable progress in applying MFCs to deal with different types of (waste)water, several issues, including the power density, durability, and costs of the electrode materials, are still to be tackled towards the commercialization of these technologies. The present manuscript provides a critical review of the recent advances and existing challenges in applying engineered nanomaterials (ENMs) to optimize the properties and performance of MFCs. The main advantages of the application of ENMs in the structure of MFCs are to provide a high specific surface area (SSA) for the electrodes, promote the electron transfer and oxygen reduction reactions, thereby representing a high level of biocompatibility for the adhesion of microbial communities, and being durable and cost-effective, especially when fabricated from natural resources. The sustainability aspects of ENMs-based MFC technologies and recommendations for future studies towards the development of sustainable nanomaterials-enabled developments of MFCs are discussed.