Chiang Mai Journal of Science

Mesoporous materials of chromium doped titanium dioxide (Cr-doped TiO2) and undoped TiO2 were prepared by hot-injection reflux technique at 150 °C for 6 hours. Samples Cr-doped TiO2 at different percentages: 1.1, 3.9 and 4.4 (wt% Cr) and undoped TiO2 were synthesized from Ti(O2)O.2H2O as titanium source obtained from the reaction of TiCl4 and H2O2. Solid (NH4)2CrO4 was a source of chromium as dopant. The prepared materials were characterized using powder X-ray diffraction (PXRD), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and N2 adsorption-desorption isotherm. The XRD results reveal that the undoped TiO2 is composed of well-crystalline anatase (major), rutile (minor) and brookite (minor) phases. In the 1.1.wt% Cr-doped TiO2, its phase composition is anatase (major) and rutile (minor). The chromium dioxide (CrO2), anatase (major), brookite and srilankite (TiO2-II) are present in the 3.9 wt% Cr-doped TiO2 and the 4.4 wt% Cr-doped TiO2. All prepared materials (Cr-doped TiO2 and undoped TiO2) exhibit mesoporous of type-IV isotherm curves with H2-type hysteresis loop according to the IUPAC classication. The Brunauer-Emmett-Teller (BET) specific surface area (SBET) and the mean pore size of the 4.4 wt% Cr-doped TiO2 exhibit a maximum surface area of 111 m2/g, corresponding to mean porous size of 4.95 nm. The hydrophilic properties of Cr-doped TiO2 were investigated with illumination of UV light. All prepared samples shows excellent superhydrophilic properties. The 4.4 wt% Cr-doped TiO2 demonstrates the most excellent superhydrophilic properties as compared with the other samples. These results allow the materials to be prospective application as antifogging.