Titania ceramic materials modified with 5%Sb and 5%W were prepared by using the sol–gel method. For the Sb-modified material, treatment with H2O2 was also performed, in order to obtain antimonic acid. The electrical conductivity of the xerogels was measured at 25C at relative humidities of 33 to 81%. At 25C, the electrical conductivity of the as-prepared 5%Sb ceramic varied from 2.02 x 10−5S/cm at 33% relative humidity to 1.12 x 10−2S/cm at 81% relative humidity. For material treated with H2O2, the conductivity varied from 1.56 x 10−5 to 2.37 x 10−2S/cm for 33% and 81% relative humidity, respectively. For the W-modified material, the conductivity varied from 1.02 x 10−5 to 2.66 x 10−3S/cm for 33% and 81% relative humidity, respectively. The activation energies observed for proton conduction were 23.5kJ/mol for TiO2/5%W, 22.9kJ/mol for TiO2/5%Sb and 20.6kJ/mol for material treated with H2O2. The highest activation energy (24.8kJ/mol) was observed for untreated TiO2. The conductivity values for the Sb-modified ceramics were superior to those reported previously for antimonic acid films, and approached the values reported for proton-conducting polymers.

Proton Conductivity in Tungsten and Antimony-Modified Titania Ceramics Prepared by the Sol–Gel Method. Vichi, F.M., Tejedor-Tejedor, M.I., Anderson, M.A.: Solid State Ionics, 2005, 176[9-10], 973-8