石墨烯掺杂聚苯胺阳极提高微生物燃料电池性能

Performance Improvement of Microbial Fuel Cell with Polyaniline Dopped Graphene Anode

微生物燃料电池(microbial fuel cell,MFC)技术可分解代谢污染物质并同步输出电能,在环境及能源领域吸引了越来越多的关注.但是,输出功率密度较低、成本较高、底物降解率低等特点限制了其实际应用,其中阳极是主要限制因素之一.本研究选取具有优异导电性、大比表面积的石墨烯和生物相容性较好的聚苯胺(polyaniline,PANI),并优化二者比例关系,制备得到石墨烯掺杂PANI复合材料.将复合材料涂覆在玻碳电极表面分析电化学性能,循环伏安(cyclic voltammetry,CV)和线性伏安扫描(linear sweep voltammetry,LSV)测试结果均显示石墨烯含量占比20%的复合电极(20%石墨烯)电化学性能最好.将复合材料修饰在碳布表面作为MFC阳极时以石墨烯含量占比5%的复合电极(5%石墨烯)生物电化学性能最佳,LSV得到最大输出功率密度为(831±45)m W·m-2,分别是20%石墨烯、1%石墨烯、石墨烯、PANI、碳布阳极的1.2、1.3、1.3、1.5、1.8倍.最大输出电压、开路电压、化学需氧量去除率、库仑效率、生物量密度均以5%石墨烯电极最高.电化学阻抗分析表明5%石墨烯电极极化内阻仅为(24±2)Ω,是碳布电极的19.8%.电化学和生物电化学性能并不完全一致,说明电极材料的生物相容性是影响MFC性能的主要因素之一.5%石墨烯阳极充分发挥了石墨烯和聚苯胺的优点,提高了MFC的产电性能.

Microbial fuel cell（MFC） technology has potential in recovering bioelectricity from different types of waste,which attracts more and more attention in the field of environment and energy.However,low power density,high cost and low substrate degradation rate,closely associated with anode performance,limit its practical application.In this study,proportional polyaniline（PANI） together with graphene was chosen to obtain the PANI dopped graphene composite.The as-received composite was modified onto the surface of glassy carbon electrode.The results of electrochemical analysis showed that the optimal mass ratio of graphene was 20% for cyclic voltammetry（CV） and linear sweep voltammetry（LSV） analysis.The anodes with 5% graphene produced a peak power density of（831 ± 45） m W·m^（-2）,which was 1.2,1.3,1.3,1.5,1.8 times of those with 20% graphene,1% graphene,graphene,PANI and carbon cloth,respectively.Moreover,5% graphene reactors showed the maximum values in output voltage,open-circuit voltage（OCV）,chemical oxygen demand（COD） removal rate,coulombic efficiency（CE）,and biomass density.The polarization resistance was only（24 ± 2） Ω in 5% graphene reactors,which was 19.8% of that of carbon cloth.The results of electrochemical analysis were not consistent with those of bioelectrochemical analysis,demonstrating that the biocompatibility of electrode was one of the important factors affecting MFC performance.5% graphene anode showed full advantages of graphene and PANI, which improved the performance of MFC.