환원 그래핀 옥사이드를 이용한 미생물 연료 전지 환원전극의 전기화학적 성능

Performance and Electrochemistry of Microbial Fuel Cell by using Activated Carbon Cathodes with Reduced Graphene Oxide

Activated carbon (AC) is an inexpensive catalyst for oxygen reduction in an air cathode of microbial fuel cells (MFCs). In the AC-based cathode, carbon black (CB) is used as a conductive supporting material. In this study, it was hypothesized cathodic performance would increase if reduced graphene oxide (rGO) replaces CB in an optimum ratio. rGO replaced CB in the four different weight ratios. Maximum power density was the best in rGO15 (2,642 mW/m 2 ) followed by rGO5 (2,142 mW/m 2 ). In the optimum external resistance operation, rGO5 and rGO showed similar power (~1,060 mW/m 2 ), higher than the others. Linear sweep voltammetry, cyclic voltammetry, and impedance spectroscopy also showed that the optimal rGO additions improved cathodic performance and reduced cathodic internal resistance. Due to the flatter and wider shape of rGO and 5 times higher electrical conductivity than CB, the rGO addition improved the cathodic performance, but the complete replacement of CB with rGO decreased the cathodic performance due to the increased thickness and the morphological crack. The optimum rGO addition is a simple and effective method for improving cathodic performance.