Preparation And Conductive Performance Of Hybrid Film Materials Based On Dawson-type Phosphorous-contaning Ternary Substituted Heteropoly Acids

Heteropoly acids(HPAs),a kind of inorganic polynuclear coordination compounds with oxygen bridges,have many exceptional physical and chemical properties,and have become ideal proton-conducting functional materials like PEMs because of their high proton conductivity.Proton exchange membrane fuel cells(PEMFCs)are efficient and environment-friendly power sources with advantages of low operation temperature,quick startup and high power density,and have become preferred power sources for many energy devices.Proton exchange membranes(PEMs)are the core parts in PEMFCs due to their crucial role in forming loops for proton conduction.However,the commercial PEMs at present are strongly limited by their high cost and extreme operating conditions,so it is a hot issue to develop novel kinds of substitutable PEMs.In this work,two kinds of ternary Dawson-type phosphorus-containing HPAs,H8P2W16V2O62(P2W16V2)and H6P2Wi6Mo2O62(P2W16MO2)have been chosen to react with hydrazine hydrate and Graphene oxide(GO)to form rGO-P2Wi6V2 and rGO-P2W16Mo2 through redox process,which were further doped into sulfonated polyether ether ketone(SPEEK)organic matrix to prepare composite membrane materials rGO-P2 Wi 6 V2@SPEEK and rGO-P2W16Mo2@SPEEK.The materials were characterized by IR,TEM/SEM and XRD.Moreover,their proton-conducting performance was studied by electrochemical impedance spectroscopy(EIS).Results show that Dawson-type structure was remained in the hybrid materials after composition;suitable content of SPEEK doped as supporters are beneficial for the film-forming properties;rGO can fix HPA molecules to improve stability via electrostatic interactions and hydrogen bonding interactions.The proton conductivity of the two materials reaches 10-2S·cm-1,and exhibits Arrhenius behavior,with the activation energy less than 20 kJ·mol-l,which proves that the proton conduction mainly complies with the Grotthuss mechanism.