Anode engineering based on Fe2O3/W2N-Ti3C2Tx for promoting the optimal microbial metapopulation in fuel cells

MFCs use microorganisms as biocatalysts to oxidize organic matter in wastewater to simultaneously treat wastewater and generate electricity. However, the practical application of MFCs is limited due to low power generation. mainly attributed to the poor performance of the anode. Here, we engineered a Fe2O3/W2N-Ti3C2Tx anode for improving biofilm attachment during MFC operation. Spectroscopic techniques and biological analysis reveal vital information for elucidating the interaction between abiotic anode surface and the microbes. The engineered Fe2O3/W2N-Ti3C2Tx anode did not only improve biofilm attachment and growth of exoelectrogenic microbes on the surface, but it also improved MFC performance by achieving a power density of 2.7 W m-2 and a remarkable current density of 17 A m-2. Which is one of the highest power densities reported for MFC operated with real domestic wastewater without adding any exoelectrogenic microbes precultured elsewhere. The thermal treatment of the anode remarkably enhanced the biofilm attachment and stability of microbial-anode interaction during long-term application.