石墨烯-多壁碳纳米管复合材料协同刃天青修饰阳极对微生物燃料电池性能的影响

【目的】利用石墨烯与多壁碳纳米管复合材料协同刃天青修饰微生物燃料电池(Microbial fuel cell,MFC)阳极,提高MFC的运行性能。【方法】以碳布为基底,采用滴涂法分别制备了刃天青/碳布(R/CC)、刃天青+石墨烯/碳布(R+GNS/CC)、刃天青+多壁碳纳米管/碳布(R+MWCNT/CC)、刃天青+石墨烯+多壁碳纳米管/碳布(R+GNS+MWCNT/CC)四种阳极材料。【结果】在降解高氯酸盐的过程中,与刃天青/碳布(最高输出电压54 m V)相比,刃天青+石墨烯/碳布、刃天青+多壁碳纳米管/碳布和刃天青+石墨烯+多壁碳纳米管/碳布阳极MFC最高输出电压分别为87、145、275 m V,分别提高了61.11%、168.52%、409.26%;高氯酸盐的还原速率也分别提高了59.1%、89.7%、147.3%。4种阳极的电化学交流阻抗(EIS)和塔菲尔(Tafel)测试发现,与刃天青/碳布阳极相比,刃天青+石墨烯/碳布、刃天青+多壁碳纳米管/碳布阳极活化内阻减小,电极反应速率提高,但刃天青+石墨烯+多壁碳纳米管/碳布阳极的活化内阻更小,电极反应速率更快,同时4种阳极附着微生物胞外聚合物(EPS)分析表明,修饰过的阳极附着微生物数量增加,多糖减少,R+GNS+MWCNT/CC阳极变化最大,更有利于微生物传递电子。【结论】石墨烯、多壁碳纳米管复合材料协同刃天青修饰MFC阳极可以减小活化内阻从而加快电子传递,进而提高MFC的性能。

Effect of the modified anode by graphene-multi walled carbon nanotubes composites material with resazurin on the performance of microbial fuel cells

Objective] The anode modified with graphene-multi walled carbon nanotube composite materials was used to enhance the performance of microbial fuel cell (MFC). Methods] The composite-material of resazurin (R/CC), resazurin+graphene (R+GNS/CC), resazurin+multi walled carbon nanotube (R+MWCNT/CC) and resazurin+graphene+multi walled carbon nanotube (R+GNS+MWCNT/CC) were dropped on the surface of carbon cloth electrode. Results] The maximum MFC output voltages of R+GNS/CC (87 mV), R+MWCNT/CC (145 mV), R+GNS+MWCNT/CC (275 mV) were increased by 61.11%, 168.25% and 409.26% and the degradation rate of perchlorate were also increased by 59.1%, 89.7%, 147.3%, respectively. The results of electrochemical impedance (EIS) and Tafel for the four anode materials implied that the anode resistance of R+GNS/CC, R+MWCNT/CC, R+GNS+MWCNT/CC were decreased relative to that of R/CC, and electrode reaction rate were increased, but R+GNS+MWCNT/CC had smaller anode electrode activation resistance and faster reaction rate. At the same time, the extracellular polymeric substances analysis of microorganism on the four anode surface indicated that the amount of microorganism and polysaccharide increased and decreased respectively, R+GNS+MWCNT/CC anode is better for electron transfer. Conclusion] The modified anode by graphene-multi walled carbon nanotubes composites material with resazurin decreased the resistance of MFC and enhanced the electron transfer rate.