BACKGROUNDMicrobial fuel cells (MFCs) are promising devices that can be used to generate electricity from organic wastewater through microbial redox reactions. Various strategies have been attempted to improve the power generation of MFCs, including electrode modification. Titanium (Ti) is a biocompatible metal which is commonly used in various applications. This study examined the improvement of voltage generation by Ti nanoparticle attachment to the carbon electrode surface of an MFC by simple dipping and e-beam evaporation. Two microbes, namely Shewanella oneidensis MR-1 and Klebsiella pneumoniae L17, having different electron transfer mechanisms were used to identify the effects of Ti nanoparticles on bioelectricity generation. RESULTSVoltage generation was significantly increased for the MFCs containing Ti nanoparticles, both using S. oneidensis MR-1 and K. pneumoniae L17. Higher concentrations of DNA extracted from the electrode surface indicated that the Ti nanoparticles did not only assist the electron transfer process from the bacteria to the electrode but also microbial attachment on the carbon electrode. Energy-dispersive X-ray spectroscopy (EDS) experiments demonstrated the sustainability of the Ti nanoparticles, showing no significant changes in the attached Ti nanoparticles during an operation period of 3weeks. CONCLUSIONIt was demonstrated that the Ti-dipping method is applicable to MFCs as an electrode modification strategy by Ti nanoparticle formation, leading to a similar level of voltage generation (but through a much simpler process) as compared with conventional evaporation methods. (c) 2019 Society of Chemical Industry