One-step fabrication of membraneless microbial fuel cell cathode by electropolymerization of polypyrrole onto stainless steel mesh

A unique one-step method for fabrication of a membraneless microbial fuel cell (MFC) cathode was developed by coating a conductive polymer onto stainless steel mesh. The resulting polypyrrole/anthraquinone-2-sulfonate (PPy/AQS) film was synthesized via electropolymerization using AQS as the dopants. The scanning electron microscopy results indicated that the PPy/AQS film was uniformly formed on the metal mesh electrode without cracks on its surface and featuring a globular structure. Being equipped with such a cathode that was able to catalyze oxygen reduction and prevent water leakage, the membraneless MFC allowed power generation over 250 h and exhibited a maximum power density of 575 mW m−2. Increasing film thickness seemed to result in a reduction in power performance due to the increased ohmic resistance of the cathode material and the enhanced difficulty for oxygen diffusion inside the cathode.