Synthesis and characterization of TiO 2 nanoparticles: anatase, brookite, and rutile

Abstract

Titanium dioxide nanoparticles have been prepared by solution-phase methods in the three phases that occur naturally, anatase, rutile, and brookite. The amorphous titania starting material was prepared from titanium(IV) iso-propoxide using iso-propanol as solvent and a small quantity of water. The resulting material was treated hydrothermally in an acid digestion vessel at temperatures between 175 ˚C and 230 ˚C with different reactants to obtain the three phases or controlled mixtures of two phases. The nanomaterials were characterized by a variety of techniques, including X-ray diffraction, Raman spectroscopy, electron microscopy, dynamic light scattering, and UV-Vis absorbance spectrophotometry. The results illustrate the relation between the properties of the nanoparticles in the colloid, in the powder, and in nanostructured thin films prepared with the materials. A thorough understanding of synthesis methods is essential for the preparation of nanomaterials with tailored structural, morphological, and ultimately, physical properties.

Highly Photoactive, Low Bandgap TiO2 Nanoparticles Wrapped by Graphene

“…The inset in Figure 3A shows plots of the Kubelka-Munk remission function (i.e., relationship of [αhν] 1/2 versus photon energy) corresponding to each spectrum, which indicates that the bandgap of bare anatase TiO 2 NPs was 3.27 eV, the same as the reported Eg value for anatase TiO 2 . [19] While the bandgap of graphene-TiO 2 NPs (two-step hydrothermal) estimated from the spectrum was 3.19 eV, the bandgap of graphene-TiO 2 NPs was significantly reduced to 2.80 eV. This phenomenon should occur due to the direct interaction between C and Ti atoms on the NP surface during hydrothermal treatment.…”

Growth inhibition of aquatic plant caused by silver and titanium oxide nanoparticles

“…One of the reasons for the large amount of toxicity data on TiO 2 -NP is the adoption of this nanoparticle by a variety of industries; TiO 2 -NP was the first nanoparticle made commercially available to various industrial and research activities. TiO 2 is a naturally occurring mineral that can exist in three crystalline forms, known as rutile, anatase, and brookite, and in an amorphous form 8 . Commercial production of TiO 2 -NP between 2006 and 2010 was estimated as 5,000 metric tons per year, more than 10,000 metric tons per year between 2011 and 2014 9 and approximately 2.5 million metric tons by 2025 10 .…”

Optical Characterization of Laser-Synthesized Anatase TiO2Nanopowders by Spectroscopic Ellipsometry and Photoluminescence Measurements

“…[12] and references therein). It is also known that widening of band gap might be expected in nanosized materials [13].…”