The Calcination Effect on the Crystallinity, Nitrogen Content, and Pore Structure of Nitrogen-Doped Titanium Dioxide

Abstract

Mesoporous nitrogen-doped titanium dioxide nanomaterials have been synthesized through a one-step sol gel process with dodecylamine as the pore template as well as the nitrogen source. The calcination process plays an important role in the crystallization process, determination of doped nitrogen, and pore formation. The effect of calcination temperature on the material structure was studied by calcination treatment of the as-synthesized material at several temperature variations. The resulting materials were characterized using FTIR, XRD, XPS, and N2 gassorption analysis. The results showed that the anatase TiO2 crystal structure began to form with calcination at 400 °C. The higher calcination temperature tends to cause the transformation of anatase crystal phase into rutile. The higher calcination temperature also affects the doped nitrogen content, where the pore-templating molecules begin to disappear at a calcination temperature and leaving a number of dopants on TiO2. All dopants are released from TiO2 at a calcination temperature of 600 °C. The optimum calcination temperature to form mesoporous structure was 450 °C, and the sintering occurs at a calcination temperature higher than optimum temperature indicated by the collapse of the pore structure.