PROF. ADUDA BERNARD O.

Citation:

Ajuoga, P. O, A., Mwabora JM, Aduda BO. "Effects of concentration of dopant states on photoactivity in niobium-doped TiO2.". In: 7th College on Thin Film Technology. Dar es Salaam, Tanzania; 2006.

Date Presented:

Abstract:

Various studies have revealed that incorporation of cations of valence higher than that of the parent cations e.g., W6+, Ta5+, Nb5+ into the crystal matrix of TiO2 enhances its rate of photoactivity. In the present study, we propose incorporation of Nb5+, pentavalent dopant into TiO2 matrix in order to attempt to establish its optimal concentration for maximum photoactivity. The niobium-doped TiO2 was prepared by high temperature diffusion of the doping cations into the crystal matrix of the parent oxide. The doped samples were found to change from white to light yellow/brown. XRD analysis for anatase-rutile content of the doped samples was performed. At low mol% Nb (0.1197 – 0.2360) in TiO2, the crystalline structure was predominantly rutile at calcinations temperature of 650 oC, but at high mol% Nb (> 1.0000), a relatively higher anatase content was observed at the same calcinations temperature for a period of 2.5 hours.