<p>Microbial fuel cells (MFCs) represent an emerging energy technology that generates electricity through microbial-organic interactions, with the anode serving as a critical component for wastewater-to-electron conversion. This study focuses on developing porous iron-nickel (Fe–Ni) alloys as potential anodes for MFCs, employing electrodeposition to fabricate these anodes with systematically varied Fe/Ni ratios. Through intrinsic electrochemical performance screening, the work aims to achieve composition optimization for high-performance microbial fuel cell anodes. Multi-dimensional analysis integrating linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel polarization was conducted to establish structure–activity relationships and synergistic catalytic mechanisms of the alloys. Key findings reveal that compositional optimization profoundly impacts the performance of these potential anodes: the Fe₇Ni₃ alloy exhibited significantly superior electrochemical activity compared to pure Ni, characterized by dramatically enhanced peak current density, and improved charge storage capacity. Furthermore, Fe₇Ni₃ demonstrated minimal charge transfer resistance and excellent reaction kinetics. These results validate that bulk composition engineering of porous Fe₇Ni₃ offers a highly promising strategy for developing potential anode materials for high-performance MFCs, effectively addressing the stability-activity trade-off inherent in conventional surface-modified anodes. This work provides a composition-driven design paradigm for bioelectrochemical systems, paving the way for future scale-up studies focusing on long-term stability and integration into wastewater treatment modules.</p> Graphical abstract <p></p>