Conductive polypyrrole hydrogels and carbon nanotubes composite as an anode for microbial fuel cells

Abstract

Conducting polymer hydrogels, a unique class of materials having the advantageous features of both hydrogels and organic conductors, possess excellent electrochemical properties due to their intrinsic porous structure. Herein, we report a facile and scalable method for synthesizing conductive polypyrrole hydrogels/carbon nanotubes (CPHs/CNTs) using phytic acid as both gelator and dopant, and this composite was used as an anode in a dual-chamber microbial fuel cell (MFC). The high electrocatalytic activity of this material significantly reduced the interfacial charge transfer resistance and facilitated the extracellular electron transfer on the anode surface. The three dimensional porous structure and hydrophilicity of this composite enhanced the biofilm formation on the anode surface. CPHs/CNTs anode increased the maximum power density from 871 ± 33 mW m⁻² to 1898 ± 46 mW m⁻² and exhibited high stability in the two-chambered MFC. These results demonstrated that the synthesis of the CPHs/CNTs composite offered an effective approach towards enhancing the power production in MFCs.