Structure and photoluminescence properties of xZrO2–(1 − x)TiO2 composite nanocrystals

xZrO2–(1−x)TiO2 (0≤x≤0.7) nanocrystals were prepared by sol–gel method. The prepared pure and composite powders were characterized by differential thermal analysis-thermogravimetry (DTA–TG), X-ray diffraction (XRD), transmission electron microscopy and electron diffraction (TEM and ED), and the photoluminescence (PL) properties of the composite nanocrystals were studied for the first time. The results showed that nanocrystals were obtained. Their crystalline size and phase composition were dependent on the ZrO2 content. ZrO2 addition suppressed the crystal growth of TiO2. The emission peak position of the composite nanocrystals heat-treated to 550 °C had 8 nm red-shift and their emission intensity became stronger compared with that of pure TiO2. The most intense emission appeared in 0.4ZrO2–0.6TiO2, which is about 2.4 times of pure TiO2 nanocrystals.