Influence of Sintering Temperatures on Structure and Electrical Conductivity of TiO2 Cathode

Abstract

The influence of sintering temperatures on the structure and electrical property of TiO₂ cathode was investigated with regards to the crystal structure and composition, microstructure, oxygen vacancies, surface properties and electrical conductivity. The as-products were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), digital four-point probe conductivity instrument (DFFPCI) and accelerated surface area and porosimetry system (ASAP). XRD analysis confirms that anatase phase TiO₂ at 700 ºC transformed to rutile phase TiO₂ and TiO_1.95 with the increase of sintering temperatures to 850 ºC and 950 ºC. The Ti°Cp binding energy of TiO₂, as studied by XPS, is discussed in terms of the valence state of the titanium ions. Digital four-point probe conductivity instrument analysis indicate that the electrical conductivity increase with the rise of temperature. Scanning electron microscopy and accelerated surface area and porosimetry system analysis indicate that the grain of the obtained TiO₂ increase but nitrogen storage properties decrease with the increase of sintering temperatures. Moreover, the experimental results show that the electrical conductivity of TiO₂ increases with the rise of the temperature.