Laccase-catalyzed electrochemical fabrication of polyaniline/graphene oxide composite onto graphite felt electrode and its application in bioelectrochemical system

Abstract

In order to develop an environmental benign method for the modification of graphite felt (GF) electrode, laccase-catalyzed electrochemical fabrication of polyaniline/graphene oxide (PANi/GO) composite at facile pH condition was investigated in this study. At the presence of laccase, aniline polymerization was remarkable at pH as high as 3.6, which was unfavorable for traditional chemical and electrochemical polymerization. The successful coating of PANi/GO on the electrode surface at the presence of laccase was verified by contact angle, scanning electron microscopy, Fourier transform infrared spectrum and Raman spectrum. The improved electrochemical property of the GF modified by PANi/GO at the presence of laccase (Lac.-PANi/GO/GF) was confirmed by cyclic voltammetry (CV) analysis. The application of the modified electrodes in the bioelectrochemical system (BES) notarized the superior electrogenesis performance of Lac.-PANi/GO/GF. Much higher power density, smaller internal resistance and shorter start-up time was achieved in the BES using Lac.-PANi/GO/GF as the anode. The maximum power density of 755.95mWm−2 in BES using Lac.-PANi/GO/GF as anode was much higher than that in BES using PANi/GO/GF and blank GF as anode, which were as low as 364.59 and 100.43mWm−2, respectively. The milder react condition, improved electrochemical activity and biocompatibility suggested that Lac./PANi/GO/GF electrode had a promising future in BES application.