In this study a simple, fast and effective surface modification method for enhanced biofilm formation, increased electron transfer rate and higher current density generation from microbial fuel cell (MFC) has been demonstrated. This method consists of partial oxidation of carbon felt material by UV/O-3 treatment. Results from the electrochemical studies performed suggest that Shewanella oneidensis MR-1 biofilm formation is favored on UV/O-3 treated carbon felt electrodes when subjected to an applied potential of -0.3 V vs. Ag/AgCl. Carbon electrodes exposed to 45 mm of UV/O-3 treatment provided the best electrochemical results and richer bacterial Cell attachment. Ozone exposure above 45 min presented decreased MFC performance and current generation. Visual confirmation via SEM images indicated a link between the current generation and the presence of biomass attached to the working electrodes. In addition, we have shown enrichment of the electrode surface with flavin, which correlates with the increased anodic performance. (C) The Author(s) 2015. Published by ECS. All rights reserved.