We demonstrate a facile selective synthesis of phase-pure anatase, rutile, and brookite nanocrystal polymorphs of titania (TiO 2 ) using a benign hydrothermal treatment of an industrial grade TiOSO 4 precursor. Acetic acid (CH 3 COOH) is used for the synthesis of anatase, glycolic acid (HOCH 2 COOH) is used for rutile, and both glycolic acid and ammonium hydroxide (NH 4 OH) are used for obtaining brookite. The detailed morphologies of the as-synthesized materials are determined from a combination of powder X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The anatase nanocrystals are terminated by low-energy {101} facets and a small amount of high-energy {001} facets, whereas the rutile nanocrystals are terminated by low-energy {110} facets and a small amount of high-energy {111} facets. The brookite nanocrystals are terminated by low-energy {210} facets and {111} facets, and not the high-energy {101} and {201} facets erroneously reported in the literature. The activities of as-synthesized TiO 2 nanocrystals as supports for vanadia−titania catalysts are investigated by measuring the selective catalytic reduction of NO using ammonia (NH 3 -SCR). The O 2 -activated samples show similar oxidovanadium(V) bands in their Raman spectra, and the relative activity relation is found to be anatase > brookite > rutile. In addition, the photocatalytic activity is evaluated by measuring the decomposition of Rhodamine B (RhB) under UV-light irradiation, and the relative activity order is found to be P25 > anatase ≈ rutile > brookite.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.