MFC bioanodes constituted of nickel sulfide nanoparticles and electroactive biofilm.

Microbial fuel cells (MFCs) are eco-friendly and sustainable energy bioelectrochemical systems (BES), which convert chemical energy directly to electricity, through the bio-catalytic oxidation of organic compounds by electro-active bacteria1,2. The improvement of microbial fuel cell (MFC) performances requires the increase in cell voltage as well as discharge current densities. The choice of an efficient cathode is a problem3 and often limits the performance of the MFC. Nevertheless, it is possible to increase the whole performance by improving bioanode operating. The modification of bioanode surface by nanoparticles4 is a suitable way to increase the efficiency of electron transfer from the bacteria and anodic current collector. For this purpose, metal sulfides are interesting compounds because they involve various redox processes occurring in natural anaerobic environments. Very few studies reported these compounds as bioanodes materials5. In this communication, we will present the results that we obtained during the study of nickel sulfide / biofilm bioanodes formed by polarization at -0.2V/AgCl/Ag in KCl-garden compost solution filled with sodium acetate as an organic substrate long-term current time transients of these bioanodes and comparison to classical carbon or stainless steel bioanodes, microscopy observations of the surface of bioanodes, discussion on the electrochemical coupling between nickel sulfide nanoparticles and electroactive bacteria.