Enhanced electrical contact of microbes using Fe₃O₄/CNT nanocomposite anode in mediator-less microbial fuel cell

A novel Fe₃O₄/CNT nanocomposite was synthesized and employed for the modification of carbon paper anode in a mediator-less microbial fuel cell (MFC) to enhance its performance. The Fe₃O₄/CNT composite modified anodes with various Fe₃O₄ contents were investigated to find the optimum ratio of the nanocomposite for the best MFC performance. The Fe₃O₄/CNT modified anodes produced much higher power densities than unmodified carbon anode and the 30wt% Fe₃O₄/CNT modified anode exhibited a maximum power density of 830mW/m². In the Fe₃O₄/CNT composite modified anode, Fe₃O₄ helps to attach the CNT on anode surface by its magnetic attraction and forms a multi layered network, whereas CNT offers a better nanostructure environment for bacterial growth and helps electron transfer from E.coli to electrode resulting in the increase in the current production with the catalytic activity of bacteria. The electrocatalytic behavior and all possible mechanism for their better performance are discussed in detail with the help of various structural and electrochemical techniques.