Microbially catalyzed enhanced bioelectrochemical performance using covalent organic framework–modified cathode in a microbial electrosynthesis system

Electrode modification plays a critical role in enhancing the bioelectrochemical performance of a microbial electrosynthesis system (MES). This study involved the modification of the conventional carbon felt (CF) electrode through in situ covalent grafting with a covalent organic framework (TpPa-COF). Subsequently, the performance of this modified electrode was assessed as a cathode in MES. Various physical and bioelectrochemical techniques, such as chronoamperometry, cyclic voltammetry, and electrochemical spectroscopy, demonstrated the remarkable stability, reduced electrode resistance, increased current density, and superior bioelectrochemical activity of the modified electrode. The application of COF@CF caused a 3.2-fold improvement in current density, leading to an enhanced production of volatile fatty acids. The rough surface of the COF@CF electrode and its abundant catalytically active sites facilitated the growth of microorganisms, particularly exoelectrogenic and fermentative genera such as Desulfitobacterium, Clostridium, and Desulfovibrio. These findings highlight the promising potential of COF@CF in various bioelectrochemical applications.