Applicability of Emerging Nanomaterials in Microbial Fuel Cells as Cathode Catalysts

Abstract

Microbial fuel cell (MFC) is a green sustainable technology that facilitates bio-electrochemical conversion from different substrates, using catalysts of varying origin in its anode-cathode units. One such widely used catalyst is Pt/C for providing conventional oxygen reduction reactions (ORR) at the cathode. Though it is widely accepted, the higher cost with limitations of stability and poisoning remains some of its major drawbacks in longer field-scale applications. As an alternative, different nanoparticles (NPs) employing transition metals, bi-metallic, and metal-free catalysts supported on conducting polymer (CPs) matrix have been examined as cathode catalysts for improved ORR kinetics. Noble metals (M) and metal oxide (MOx) nanoparticles (NPs) have been introduced as promising, cost-effective electro-active materials in MFCs. In effect, the electro-activity and efficacy of the materials like conducting polymers (CPs), graphene oxide (GO), reduced graphene oxide (rGO) and graphene quantum dots (GQDs) have been duly enumerated with incorporated different formulations of M/MOx components. The relative impacts of these nanoparticles have shown promising results in MFCs with higher conductivity and systemic power output. In the context of developing alternative cathode catalysts, the current status of the applicability of these emerging NPs in MFCs for providing altered ORR in the process is comprehensively explored. Further, future research prospects in the domain of these emerging NPs with probable directions of progress in the field of catalytical electrochemistry are presented.