A biomass-based activated carbon, utilized for direct carbon fuel cells (DCFCs), is prepared from bamboo scraps under different activation temperatures, activation times, and impregnation ratios. The K2CO3 is employed as the activating agent, while the activated carbon is treated in HNO3 solution for the purpose of surface modification and ash removal. The applicability of the prepared activated carbon for DCFCs is evaluated by a fluidized bed electrode direct carbon fuel cell anode. It is found that the BET surface area of the activated carbon could reach 1264 m(2) g(-1) under the following conditions: activation temperature, 1173 K; activation time, 2 h; impregnation ratio, 1. The content and diversity of the surface oxygen functional groups of the activated carbon could be well improved through the HNO3 treatment, and the ash content is notably reduced. Differently, the BET surface area is slightly reduced while the electrical resistivity is remarkably increased. The optimal HNO3 solution concentration is estimated to be 2 mol L-1, giving the treated bamboo-based activated carbon outstanding polarization performance among the tested carbon fuels.