Proton Conduction in the Sol-Gel-Derived Glasses

Abstract

The sol-gel method was used for the preparation of high proton-conducting glasses. The proton conductivities were investigated to relate with the pore structure, adsorbed water molecules and glass compositions. The conductivities follow the Arrhenius equation and the activation energy decreases with increasing the logarithm of the product of proton and water concentration. The proton conduction is promoted by the dissociation of proton from the hydroxyl bonds and the proton hopping through water molecules, the conductivities of which proportionally increase in log-log scale with the increasing content of both the hydroxyl and water molecules in the pores. The effect of pore size and the glass components on the proton conduction was quaintly elucidated. High conductivity of ∼10^-2 S/cm at room temperature was achieved for the P₂O₅-SiO₂ glasses. The preparation of pore-controlled glass films was also described.