Study On Electrochemical Characteristics Of Graphene Oxide Film During Mass Transfer

With the shortage of water resources and water pollution becoming more and more serious,membrane separation technology has been developed rapidly.However,the material cost and operation cost of separation membrane are still very high,which seriously restricts the development of membrane technology.Graphene oxide,carbon nanotubes and their derivatives,as the representative of carbon nanomaterials,can greatly improve the water flux with the same retention rate,which can greatly reduce the operating cost,so they have been widely concerned by researchers.In this paper,graphene oxide film were prepared by vacuum filtration and characterized by electrochemistry under different conditions.The electrochemical impedance spectroscopy of graphene oxide film and polyethersulfone microfiltration film was studied.It is found that there is an obvious peak in the phase diagram of electrochemical impedance spectrum of graphene oxide film compared with polyethersulfone microfiltration film,which proves that graphene oxide film produces corresponding electrochemical signals.It shows that EIS has potential value in the characterization of graphene oxide films.The results show that in the process of ion diffusion,the change of graphene oxide film spacing caused by the change of electrolyte concentration has little effect on ion diffusion.The diffusion hindrance of ions is mainly due to the Donan repulsion caused by the negative charge of graphene oxide film in aqueous solution.The I-V curve of graphene oxide film under different conditions is studied.It is found that the distance between the layers of graphene oxide film affects the linear slope of the ohmic region of the I-V curve and the current value corresponding to the platform.The smaller the distance between the layers,the smaller the linear slope and the current value corresponding to the platform.The charge on the surface of graphene oxide film affects the length of the platform in the concentration polarization region of the I-V curve.