The three-dimensional (3D) macroporous anodes were constructed by coating carbon nanoparticles (graphene, carbon nanotube, or activated carbon) on stainless steel fiber felts (SSFFs) that have an open, solid and macroporous structure. These modified electrodes provided large surface area for reaction, interfacial transport and biocompatible interface available for bacterial colonization and substrate transport. Graphene modified anode delivered a maximum power density of 2142 mW m(-2) at a current density of 6.1 A m(-2) in MFC, greatly improved the performance of MFC compared with the unmodified SSFF-MFC. Electrochemical impedance spectroscopy (EIS) measurements together with the polarization curves demonstrated that carbon nanoparticles modified anodes could greatly decrease MFCs' internal resistance. Our experimental results also proved that embedding carbon nanoparticles into 3D macroporous metallic scaffold is a promising method for MFC anode fabrication. (C) 2014 Elsevier B.V. All rights reserved.