Bimetallic Cu-NC/Co-NC nanocomposite from metal-organic framework precursors as a cathodic electrocatalyst for enhanced microbial fuel cell performance

Developing an affordable catalyst for microbial fuel cells (MFCs) is essential for advancing alternative energy sources and promoting environmentally sustainable power generation. Herein, an active bimetallic Cu-NC/Co-NC nanocomposite was developed as a novel cathodic electrocatalyst using copper-1,3,5-benzene tricarboxylic acid and zeolitic imidazole framework-67 through controlled pyrolysis under nitrogen atmosphere. The synergistic interaction between Cu and Co active centers is specifically designed to enhance oxygen reduction reaction in a two-chamber MFC. Structural and morphological characteristics revealed that the Cu-NC/Co-NC nanocomposite exhibits a hierarchically porous architecture with a large specific surface area and uniformly distributed metal-nitrogen active sites, which facilitate rapid mass transport and efficient electron transfer. The Cu-NC/Co-NC catalyst, when applied as the MFC cathode, delivers a maximum power density of 211 mW/m2 along with an open-circuit potential of 665 mV, which is an indicator of its promising electrochemical performance. Also, the system achieves an excellent wastewater treatment efficiency of 96% in terms of chemical oxygen demand removal, highlighting its dual functionality for simultaneous energy recovery and wastewater treatment. These experimental results underscore the potential of metal–organic framework-derived Cu-NC/Co-NC nanocomposite as a durable and efficient cathodic electrocatalyst for bioelectrochemical systems and environmental applications.