fig2

Figure 2. (A) Schematic diagram of 3DP GA electrode preparation (up) and polymerization of the 3DP GA/PPy electrode (down). (B) Schematic diagram of the 3DP GA biocathodes facilitating ion and gas transport. (C) SEM images of biofilm formation on the 3DP GA/PPy cathodes from the outer and inner electrode surface. (D) Start-up current of the biocathodes at the potential of -1.0 V vs. Ag/AgCl. (E) EIS curves. (F) CH₄ production rate of the 3DP GA and CF biocathodes. This figure is quoted with permission from He et al.^[21].