Development of highly efficient bimetallic nanocomposite cathode catalyst, composed of Ni: Co supported sulfonated polyaniline for application in microbial fuel cells

To develop a cost-effective efficient non-noble cathode electrocatalyst with enhanced oxygen reduction is one of the major concerns in optimizing electrical efficiency in microbial fuel cells (MFCs). The study here demonstrates the evaluation of synthesized non-noble bi-metallic [1: 1 Nickel (Ni): Cobalt (Co)] nanocatalyst supported on sulfonated polyaniline (SPAni) in MFC. The homogeneous dispersion of nanoparticles on supporting matrix was confirmed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Inductive coupled plasma - optical emission spectroscopy (ICP-OES) also shows the uniform distribution of (1: 1) Co and Ni nanoparticles over the polyaniline hetero-structure for Ni-Co/SPAni and Ni-Co/PAni nanocatalyst system. Furthermore, the high specific surface area [Multipoint Brunauer-Emmett-Teller (MBET)] of Ni-Co/SPAni catalyst associated with the uniform dispersion and high porosity makes it promising catalyst material for fuel cell applications. Among all the synthesized electrocatalysts, 1: 1 Ni-Co/SPAni catalyst revealed the highest catalytic activity with the enhanced stability towards oxygen reduction reactions (ORR). Moreover, in MFC, a maximum power density of similar to 659.79mWm(-2) was observed with prospective Ni-Co/SPAni catalyst compared to the corresponding Pt/C catalyst (similar to 483.48mWm(-2)). The results indicate the potential application of a conducting polymer such as SPAni as supporting matrix in bimetallic Ni-Co catalyst system that could alternatively serve as an efficient cathode catalyst over the traditionally used costly Pt/C catalyst in MFCs operation. (C) 2018 Elsevier Ltd. All rights reserved.