ZnSe-doped N-C skeleton-driven electrode for enhanced electron transport in microbial fuel cells

Abstract

Microbial fuel cells (MFCs), a promising green energy source, have faced limitations in performance. To address this, we synthesized a porous Zn-Se-N-C nanomaterial with a large specific surface area and significant defect density through the utilization of metal–organic frameworks (MOFs). Surface unique topography characteristics are tuned by controlling the annealing temperature. Density functional theory (DFT) calculations confirmed that the synergistic effect of Zn and Se in ZnSe nanoparticles can significantly improve oxygen reduction reaction (ORR) electrocatalytic activity. Experimental results demonstrated that the ORR performance of Zn-Se-N-C 1000 °C catalyst is comparable to that Pt/C catalyst in both alkaline and neutral conditions, especially in alkaline media. When employed as the cathode catalyst in asymmetrical MFCs with a neutral anode and an alkaline cathode, the Zn-Se-N-C 1000 °C(cathode)-MFC system achieved an impressive output current density of 8 ± 0.2 A/m−2 and a remarkable power density of 2000 ± 30 mW m−2. Additionally, the unique pore structure of Zn-Se-N-C1000°C made it highly suitable as an anode in MFCs. The Zn-Se-N-C 1000 °C (anode)-MFC demonstrated an output current density of 7.1 ± 0.9 A/m−2 and a power density of 3000 ± 111 mW m−2.