The Study Of Laccase-catalyzed Electrochemical Fabrication For The Electrode Modification

Biological electrochemical system (bioelectrochemical system, BES) draw much attention of researchers both domestic and abroad because of its advantages of green renewable, who is a new kind technology of transform wastewater chemical energy into electrical energy by microorganism. However, the limited out-put power of BES largely restricted its actual application in BES for wastewater treatment. Low out-put power density may be caused by the influence of anodic electron transfer rate. Modification of the anode is an important way for increasing the anodic electron transfer rate. Modified anode electrode can also increase the electrode electrochemical performance, biocompatibility, surface roughness and so on, which would increase production capacity of BES. As a result, the anode modification has been difficulty and hotspot in the research of the BES.In this paper, the first part is about the the influence of laccase as a catalyst during electropolymerization of aniline modified graphite felt electrode. Results of FTIR and Raman show that polyaniline has been successfully load in the graphite felt electrode surface in the presence of laccase under the condition of pH 3.6 (Lac.-PANi/GF). The cyclic voltammograms (Cyclic voltammetry, CV) was used to prove that the modified electrode electrochemical performance has been greatly improved, the scanning electrode (Scanning electron microscopy, SEM) was used to observe the surface morphology change of the modified electrode to certify that polymer was obvious thickening. When the modified electrode applied in the BES as anode, maximum power density of Lac./PANi/GF was 314.55 mW m-2, much bigger than the maximum power density of PANi synthesized only by electropolymerization (PANi/GF) of 186.41 mW m-2, the above results show that laccase can be used as a catalyst during electropolymerization.Due to carbon material modified anode is widely studied, the method of electrochemical assemble polyaniline/graphene oxide (PANi/GO) compounds have been reported, it is necessary to study the influence of laccase catalyze electrochemical fabrication of PANi/GO composites modified electrode. The second part of this paper is to research the improvement when laccase-catalyzed electrochemical fabrication of PANi/GO composites modified electrode and its application in BES. The material loaded on the electrode surface was determined by scanning electron microscopy (SEM), FTIR and Raman. The improvement the electrochemical performance is verified by CV. All modified electrode was applied in the BES to verify the electrode Lac.-PANi/GO/GF whose electropolymerization catalyzed by laccase has more superior performance production (maximum power density was 755.95 mW m-2). Compared with the control reaction without laccase, the presence of laccase can hang more GO. The polymerization condition was moderate, reaction rate was fast, reaction degree was thoroughly. The mild reaction conditions, higher load rate, better electrochemical properties and biocompatibility means laccase catalytic electrochemical fabrication of PANi/GO composites for the graphite felt modification has a broad prospect in BES.