Biomass-derived 3D hydrogel bioanode for improved EET processes and COD removal efficiency

Abstract

Microbial fuel cells (MFCs) have garnered significant attention in power generation and wastewater treatment fields. Current MFCs have relatively low power density due to limited biofilm colonization and sluggish extracellular electron transfer (EET) processes. Here, a hybrid hydrogel (PPy-CMC-MXene) was prepared by doping MXene with an inexpensive and readily available biomass source carboxymethyl cellulose and polypyrrole. The MFC equipped with the PPy-CMC-MXene/CC anode exhibited a 2-, 30-, 59-, and 4.8-fold power density, specific capacitance, electron transfer efficiency, and coulombic efficiency, respectively, relative to the original carbon cloth (CC) anode. More notably, the MFC equipped with the PPy-CMC-MXene/CC anode had an excellent chemical oxygen demand (COD) removal efficiency of 89.2%. It was shown that the PPy-CMC-MXene/CC electrode offered good biocompatibility and was beneficial to the enrichment of Proteobacteria and Acinetobacter. The anode material has some application prospects in water treatment and the adsorption of electricity-producing bacteria.