Impact of Surface Properties of Porous SiOC-Based Materials on the Performance of Geobacter Biofilm Anodes

Abstract

Porous SiOC tapes were studied as anodes for bioelectrochemical system (BES) using Geobacter spp. as an electroactive microorganism (EAM). The ceramic anodes were produced by tape-casting of poly(silsesquioxanes), tailoring the surface properties by incorporating graphite and carbon black, and changing the pyrolysis temperature. By varying these parameters, the specific surface area, the hydrophilicity, and the roughness were adjusted, with the pyrolysis temperature playing a major role. When used as anodes at 0.2 V vs. Ag/AgCl sat. KCl in the BES, maximum current densities relative to the geometric surface area (jGSA) up to 5.8 A m−2 were achieved. Microbial community analysis of the biofilm shows the dominant presence of Geobacter spp. as the EAM. Benchmarking the performance of the anodes of this study with anodes using the same EAM demonstrates that porous SiOC anodes are a promising class of materials, as they show jGSA comparable to carbon-based anodes.