Akademik Veri Yönetim Sistemi
Journal of Photochemistry and Photobiology A: Chemistry, cilt.468, 2025 (SCI-Expanded)
Nanorod/nanotube-like TiO2 photocatalysts were prepared hydrothermally at 130, 155, or 180 °C starting from commercial anatase (Merck) or home-made rutile TiO2 samples, which were then calcined at different temperatures. After the hydrothermal process, the anatase or rutile TiO2 samples mainly rearranged into a mixture of low crystallinity anatase solid with a high specific surface area (up to 336 m2/g). The samples were characterized by XRD, SEM, BET, XPS, DRS, FT-IR, TGA, PL, and (photo)current analyses. New relationships between the TiO2 crystallinity and the XPS, PL and DRS analysis results were obtained. TiO2 catalysts were used for the partial oxidation of 3-methylpyridine, 3-pyridinemethanol and 4-methoxybenzyl alcohol to the corresponding carbonyl molecules and showed much better results than the commercial anatase one, used for comparison. The calcination temperature influenced the product conversion rate and the product selectivity, the latter being obviously mainly dependent on the type of substrate. In fact, those calcined at 300 °C after hydrothermal treatment showed the best results in terms of both photoactivity and selectivity towards the oxidation products of 3-methylpyridine and 3-pyridinemethanol, while those calcined at 500 °C proved to be more efficient for the oxidation of 4-methoxybenzyl alcohol. The presence of scavengers during photocatalytic reactions was also used to indicate which radical species and/or directly photoproduced electrons and holes influenced the reaction rate and selectivity towards the oxidation product.