Mo2C/N-doped 3D loofah sponge cathode promotes microbial electrosynthesis from carbon dioxide

Microbial electrosynthesis (MES) is a promising technology through which carbon dioxide is converted into chemicals via bioelectrochemcal reaction. In this study, a natural loofah sponge (LS) was directly converted into a 3D macroporous carbon cathode through carbonization. The LS was codecorated with polydopamine and Mo2C (Mo2C/N-doped LS). Results revealed that the acetate production rate of MES with Mo2C/N-doped LS increased by 2.5 times compared with that of carbon felt. The maximum acetate concentration of 6.08 g L−1 and 64% of coulomb efficiency (CE) were obtained in MES with Mo2C/N-doped LS. Electrochemistry, scanning electron microscopy, and microbial community analyses showed that Mo2C/N-doped LS contributed to biofilm formation and improved the enrichment of electrochemically active bacteria. Thus, this study introduced a promising method for the fabrication of 3D cathodes with a high electrocatalytic activity from low-cost sustainable natural materials to improve MES efficiency.