Synthesis of TiO2 Tubes Via Dissolution of TiOSO4 Rod Using H2O2

We demonstrate here for the first time an original and facile approach to preparing titanium oxide (TiO2) tubes using hydrogen peroxide (H2O2) and titanyl (IV) oxysulfate (TiOSO4) as sacrificial templates. The method involves dissolving TiOSO4 powder in H2O2 solution and subsequently applying thermal treatment on the resulting amorphous precipitate. Prepared samples were characterized by X-ray diffraction, scanning electron microscopy (SEM) images, thermogravimetric (TG) analysis, and UV-vis analysis. Experimental results indicated that the samples exhibit tube-like structures with lengths of approximately 1.9 mm in diameter and 11.5 mm in length. Anatase and rutile phases were formed after annealing at different temperatures in air. The crystallite size estimated by Rietveld refinement showed an increase from 34.69 to 354.28 nm with an increase in the annealing temperature from 600 to 1000 °C. At the same time, the band gap values decreased from 3.14 to 2.97 eV. The electron density maps were calculated, and the electronic density was observed to increase from 497.56 e- Å-2 (600 °C) to 533.10e- Å-2 (740 °C) and decrease with the annealing temperature of samples. A possible mechanism for the formation of TiO2 tubes was proposed. (AU)