Influence of La3+/Ce3+-doping on phase transformation and crystal growth in TiO2-15 wt% ZnO gels

Abstract Titania based ceramic is a good candidate for environmental sensing materials. Ion doping is an effective method to improve the properties by modifying their microstructure and phase composition. By using differential thermal analysis and X-ray diffraction methods, the transformation behaviors of La 3+ /Ce 3+ -doped TiO 2 -15 wt% ZnO gels were studied so as to modify the phase transformation and decrease the granularity of crystals. Experimental results show that, anatase, rutile and ZnTiO 3 nanocrystals can be tailored by varying La 3+ /Ce 3+ contents and sintering temperatures. La 3+ /Ce 3+ doping decreases the transformation temperature of gel to anatase and the forming temperature of ZnTiO 3 phase, enhances the transformation temperature of anatase to rutile and results in appearance of Zn 2 Ti 3 O 8 interphase. With the increases of La 3+ /Ce 3+ contents, the transformation rates of ZnTiO 3 , gel to anatase and anatase to rutile, as well as the granularity of the crystals are reduced. Ultimately, the action mechanism of La 3+ /Ce 3+ doping was discussed.