Phase composition tuning by high-energy ball milling of titanium dioxide powders

In this work, titanium dioxide was modified by high-energy ball milling using jars and grinding balls made of high-strength ceramics, namely, zirconium dioxide ZrO2, stabilized with yttrium oxide Y2O3, and the stability of anatase and rutile nanopowders under high mechanical load was studied. The examined nanopowders were certified by a complex of physical methods, such as XRD, BET, SEM, TEM, XPS, diffuse light scattering, and Raman spectroscopy. Analysis of the obtained experimental data showed that ball milling of TiO2 (rutile, sp.gr. P42/mnm) decreased the size of CSR particles to 20 nm and increased the specific surface area from 8 to 36 m2/g. Milling of TiO2 (anatase, sp.gr. I41/amd) resulted in phase transformations and the formation of several titanium dioxide phases, namely, a high-pressure phase TiO2-II (columbite, sp.gr. Pbcn), TiO2-B (bronze, sp.gr. C2/m) and TiO2 (rutile, sp.gr. P42/mnm); in addition, the average size of CSR particles decreased to 8 nm and the specific surface area increased from 8 to 45 m 2/g. It was established that during ball milling, defects were introduced into the system and the concentration of Ti3+ ions changes, which was confirmed by XPS, TEM, and Raman spectroscopy data; these ions have a positive impact on the photosorption properties of the material. Besides, milling increased the number of grain boundaries and interfaces, which enhanced the surface energy of the powder, adsorption properties and stability of catalysts.