Metal-Organic Framework-Based Electrode Platforms in the Assembly of Biofuel Cells and Self-Powered Sensors

Abstract

Bioelectricity or bioelectrochemical energy conversion, which is not subjected to Carnot's limitation, is a greener alternative to renewable energy sources. However, the sluggishness of electron transfer between enzyme/microorganisms and the electrodes and low efficiency of electron capture at the electrodes limit the power densities to lower levels. Development of rugged low power density devices with prolonged life is suitable for applications such as powering implantable devices, fabrication of self-powered sensors, powering remote sensors, wastewater treatment and bioelectrosynthesis. Metal organic frameworks (MOFs) are versatile materials with high surface area that can act as exoskeletons for enzymes/microorganisms to stabilize and protect them from denaturation with retention of their activity for a prolonged period, thereby enabling robustness to the biocatalyst. Further MOFs and MOF-derived carbonaceous materials are shown to perform better than Pt/C catalysts for the oxygen reduction reaction (ORR), the often used cathodic reaction in a biofuel cell. The role of MOFs in the area of bioelectrochemical energy conversion, especially with respect to applications in biofuel cells and self-powered sensors, is discussed in detail in this Review.