Entropy-Engineered HEO/Fe, N-CNT Bioanode via Flash Joule Heating: Accelerated Electron Harvesting and Directed...

Extracellular electron transfer (EET) at the microbe-anode interface remains a critical bottleneck in microbial fuel cells (MFCs). While high-entropy oxides (HEOs) show promise for enhancing anode kinetics, conventional synthesis methods yield poor interfacial integration and fail to elucidate entropy-driven EET mechanisms. Herein, an entropy-engineered bioanode fabricated via ultrafast flash Joule heating (FJH) is reported, which uniformly anchors HEO nanoparticles (Fe─Co─Ni─Cr─Mn─O) onto vertically aligned Fe, N-doped carbon nanotubes grown on carbon cloth (HEO/Fe, N-CNTs/CC). This design synergizes CNT conductivity with HEO pseudocapacitance, achieving a record power density of 3.76 W m^-2, surpassing the state-of-the-art HEO anode by 9.6% and bare carbon cloth by 2.2-fold. The entropy-broadened conduction bands and strengthened cytochrome adsorption (ΔE_ads = -3.20 eV) reduce the electron tunneling distance to 2.47 Å, as revealed by DFT calculations. Furthermore, the anode promotes Geobacter enrichment (71% biofilm abundance) and riboflavin secretion, facilitating dual direct and mediated EET pathways. This work establishes entropy modulation as a universal strategy for high-performance bioelectrochemical systems, opening avenues for sustainable energy harvesting and environmental sensing.