Electricity production from macroalgae by a microbial fuel cell using nickel nanoparticles as cathode catalysts

Electricity production from macroalgae (Saccharina japonica) by microbial fuel cells (MFCs) was studied. The macroalgae were pretreated in alkaline solution and used as substrates in the MFC, or anaerobically fermented and then the fermentation broth was used as the MFC substrate. When pretreated S. japonica, fermentation broth, and acetate were used as substrates for a MFC with a Pt-based cathode, the maximum power densities achieved were 99, 584, and 721 mW/m2, respectively. Ni particles with 3D nanostructure were also synthesized for use as cathode catalysts. The MFC with a Ni-based cathode delivered maximum power densities of 560 and 540 mW/m2 using acetate and fermentation broth of S. japonica, respectively, which were close to those for the MFC with a Pt-based cathode. The results indicated that pretreatment of macroalgae by anaerobic fermentation can be used to realize high MFC performance and nanostructured Ni is a promising alternative catalyst in MFC application.