Electrodeposited polyaniline on graphite felt (PANI/GF) improves start-up time and acetate productivity of microbial electrosynthesis cell

Microbial electrosynthesis (MES) for CO₂ capture and utilization has been highlighted for carbon-negative intermediate chemical production. Interface engineering of the electrode surface promotes electron uptake by electroactive bacteria through extracellular electron transport systems and is essential for enhancing acetate production from CO₂. A polyaniline (PANI) electrodeposited graphite felt (GF) electrode was developed to improve acetate production and start-up time in MES. The high biocompatibility and electrical conductivity of PANI promoted biofilm formation by increasing the interfacial interaction of electroactive bacteria. The physicochemical properties of PANI/GF were analyzed by Energy dispersive X-ray spectroscopy, Fourier transform infrared spectrometry, Raman spectroscopy, and X-ray diffraction. PANI/GF reduced the average start-up time of the batch operation by three days compared to the unmodified GF. PANI/GF produced higher acetate levels (61.8 g/m² cat/day) from CO₂ than the unmodified GF (41.6 g/m² cat/day). The PANI/GF electrodes promoted biofilm formation on the surface. In conclusion, the PANI/GF-modified electrodes facilitate electroactive bacteria-carbon surface interactions and extracellular electron transfer to improve the performance of MES.