Binder-free SeNP-decorated cathodes and bioanodes for dual-chambered microbial fuel cells

Microbial fuel cells (MFCs) offer a promising dual-function solution for sustainable energy generation and wastewater treatment. However, improving their power output remains a significant challenge due to conventional conductive binders’ high cost and limited conductivity. This study introduces a novel approach by developing a binder-free selenium nanoparticle (SeNP)–decorated cathode and integrating a bioanode to enhance MFC performance. The cathode was prepared by simple dip-coating method. SeNPs were synthesized using ascorbic acid and the extracellular extract of lysinibacillus xylanilyticus, providing a cost-effective and eco-friendly cathode modification. Concurrently, Shewanella putrefaciens was immobilized on the anode to enrich electroactive biofilms and facilitate extracellular electron transfer. The MFC designed with a binder-free SeNP-decorated cathode (B-Se-G) and bioanode achieved a record-high power density of 7000 µW/m2, significantly superior to C-Se-G (4761 µW/m2) and the bare graphite electrode. This improvement was attributed to enhanced electrochemical catalytic activity, higher extracellular electron transfer efficiency, increased chemical oxygen demand removal, and improved coulombic efficiency. Integrating an exoelectrogen-enriched bioanode and a binder-free selenium-decorated cathode represents a breakthrough in MFC technology, offering a scalable, cost-effective, and sustainable solution for simultaneous wastewater treatment and bioelectricity generation. These findings provide new insights into optimizing MFC architecture for enhanced performance and practical implementation.