Polyaniline/mesoporous tungsten trioxide composite as anode electrocatalyst for high-performance microbial fuel cells

Abstract

A composite, polyaniline (PANI)/mesoporous tungsten trioxide (m-WO(3)), was developed as a platinum-free and biocompatible anodic electrocatalyst of microbial fuel cells (MFCs). The m-WO(3) was synthesized by a replicating route and PANI was loaded on the m-WO(3) through the chemical oxidation of aniline. The composite was characterized by using X-ray diffraction, Fourier transform infrared spectrum, field emission scanning electron microscopy, and transmission electron microscopy. The activity of the composite as the anode electrocatalyst of MFC based on Escherichia coli (E. coli) was investigated with cyclic voltammetry, chronoamperometry, and cell discharge test. It is found that the composite exhibits a unique electrocatalytic activity. The maximum power density is 0.98 W m(-2) for MFC using the composite electrocatalyst, while only 0.76 W m(-2) and 0.48 W m(-2) for the MFC using individual m-WO(3) and PANI electrocatalyst, respectively. The improved electrocatalytic activity of the composite can be ascribed to the combination of m-WO(3) and PANI. The m-WO(3) has good biocompatibility and PANI has good electrical conductivity. Most importantly, the combination of m-WO(3) and PANI improves the electrochemical activity of PANI for proton insertion and de-insertion.