High proton-conducting glasses were prepared by using the sol-gel method. The conductivities were studied as a function of the pore structure and the adsorbed water content. The pore structures of the glasses were controlled by adding formamide during synthesis. The specific surface areas of the pores were varied from 200 to 900m2/g. The glasses absorbed water molecules upon exposure to a humid atmosphere. The conductivity increased with the logarithm of the H2O content, and attained a saturated value above the water vapour pressure of 0.8. The highest conductivity, of 0.02S/cm at room temperature, was found for a 95SiO2-5P2O5 glass which was heated at 700C, and absorbed H2O.

High Proton Conductivity in Porous P2O5-SiO2 Glasses. M.Nogami, R.Nagao, C.Wong, T.Kasuga, T.Hayakawa: Journal of Physical Chemistry B, 1999, 103[44], 9468-72