Introduction of arylamine functional groups to graphite electrodes results in improved initial catalysis for acetate oxidation by microbial biofilms over that observed on unmodified anodes. Arylamine modified anodes achieve a current density of 3.4 A m⁻² whilst unmodified anodes achieve only 1.3 A m⁻² during the first batch feed cycle. The surface functionalization strategy provides a route to enhancing microbial bioelectrochemical systems process performance and for studying the complex mechanisms involved in such systems.