Improving the anode performance of microbial fuel cell with carbon nanotubes supported cobalt phosphate catalyst

Microbial fuel cell (MFC) is a sustainable technology that can convert waste to energy by harnessing the power of exoelectrogenic bacteria. However, the poor biocompatibility and low electrocatalytic activities of surface usually cause weak bacterial adhesion and low electron transfer efficiency, which seriously hampers the development of MFCs. Herein, a novel carbon nanotube supported cobalt phosphate (CNT/Co-Pi) electrode is fabricated by assembling CNTs on carbon cloth, followed by the electrodeposition of Co-Pi catalyst. The deposited amorphous Co-Pi thin film contains phosphate and the cobalt ions of multiple oxidation states. The hydrophilic phosphate can promote the adhesion of microorganisms on electrode. The strong conversion ability of multiple states of cobalt offers excellent electrocatalytic activity for the electron transfer across biotic/abiotic interface. Therefore, the highly conductive CNTs substrate, along with the Co-Pi catalyst, provide an effective electron transfer between the electrogenic bacteria and the electrode, which endows MFC high power densities up to 1200 mW m^-2. Our work has demonstrated for the first time that CNT/Co-Pi catalyst can promote the interfacial electron transfer between electrogenic bacteria and electrode, and highlighted the application potentials of Co-Pi as an anode catalyst for the fabrication of high performance MFC anodes.