石墨烯复合多孔碳毡气体扩散阴极的H_(2)O_(2)催生性能与机理

Performance and Mechanism of Graphene-carbon Felt CompositedGas Diffusion Cathode for Hydrogen PeroxideElectrochemical Production

采用浸渍-烧结法分别制备了石墨烯和科琴黑复合碳毡气体扩散阴极,对其微观形貌及电化学H_(2)O_(2)催生性能进行对比研究,发现石墨烯-碳毡复合阴极具有显著鳞片状微观结构及表面丰富的含氧官能团,其H_(2)O_(2)产率远高于科琴黑-碳毡复合阴极.通过调控石墨烯-碳毡复合阴极制备过程中无水乙醇的添加量、石墨烯/聚四氟乙烯(PTFE)质量比及烧结温度等条件,提升石墨烯-碳毡复合阴极H_(2)O_(2)的催生性能.采用线性扫描伏安法(LSV)、恒电位阻抗法(EIS)、傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)等测试手段,研究了不同制备条件对石墨烯-碳毡复合阴极H_(2)O_(2)催生性能的响应机理.结果表明,当无水乙醇的添加量为60mL,石墨烯与PTFE质量比为3∶1,烧结温度为360℃时,制备的阴极导电性较好,表面C=O官能团含量高,经90 min电化学反应后,H_(2)O_(2)累积浓度可达427.63 mg/L.该阴极循环稳定性强、 H_(2)O_(2)催生效率高,较目前广泛采用的碳黑-PTFE阴极具有显著优势.

Graphene and Ketjen black composite carbon felt gas diffusion cathodes were prepared by impregnation-sintering by adjusting the amount of anhydrous ethanol,the mass ratio of graphene to polytetrafluoroethylene(PTFE),sintering temperature and other factors during method,and their microstructure and H_(2)O_(2) electrochemical catalytic performance were compared.Due to the scaly microstructure and abundant oxygen-containing functional groups,graphene-carbon felt composite cathode has higher H_(2)O_(2) yield than Ketjen black-carbon felt composite cathode.The H_(2)O_(2) catalytic performance of graphene-carbon felt composite cathode was improved by regulating the preparation process,and the response mechanism of different manufacture parameters on the H_(2)O_(2) catalytic performance of graphene-carbon felt composite cathode was studied by means of linear sweep voltammetry(LSV),electrochemical impedance spectroscopy(EIS),Fourier transform infrared spectroscopy(FTIR),X-ray photo-electron spectroscopy(XPS)and other testing methods.The research results show that when the addition amount of anhydrous ethanol is 60 mL,the mass ratio of graphene to PTFE is 3∶1,and the sintering temperature is 360℃,the prepared cathode has high conductivity and high surface C=O functional group content.After 90 min of electro-chemical reaction,the cumulative concentration of H_(2)O_(2) can reach 427.63 mg/L.This cathode has strong cycling stability and high H_(2)O_(2) generation efficiency,which has significant advantages over the widely used carbon black/PTFE cathode.It is anticipated that this work could provide a theoretical basis and technical method reference for the efficient electrochemical production of H_(2)O_(2) of gas diffusion cathodes based on graphene.