One-Step Synthesis of TiO₂(B) Nanoparticles from a Water-Soluble Titanium Complex

Abstract

We report the first successful synthesis of TiO 2 (B) nanoparticles by a one-step hydrothermal process. The process was performed under acidic conditions in a 0.59 M H 2 SO 4 solution at 160 °C for 24 h or at 200 °C for 6 h using a titanium metal complex with glycolic acid. The prepared nanoparticles were characterized by XRD, Raman spectroscopy, and TEM. TiO 2 (B) is a metastable phase and is one of the most intriguing forms of titanium oxide. All synthesis methods for TiO 2 (B) reported to date have required a multistep process involving solid-state synthesis of an alkali metal titanate, an ion-exchange reaction, and gentle dehydration.

Application of Water-Soluble Titanium Complexes as Precursors for Synthesis of Titanium-Containing Oxides via Aqueous Solution Processes

“…These dimeric species cannot effectively build a brookite lattice, but they are suitable building blocks for the rutile lattice (Figures 31c and 31d). Although the explicit reason for the formation of TiO 2 (mC) at pH 1 remains unclear, we 69 protons below pH 3.5, 83,84 which in turn indicates that under the present hydrothermal conditions at pH 1, the nucleation process is presumably driven toward protonated species such as H 2 Ti 3 O 7 and H 2 Ti 4 O 9 .…”

“…67,68 has shown that TiO 2 (mC) can be prepared almost universally from proton exchange and subsequent dehydration of a series of layered titanates with the general formula of A 2 Ti n O 2n+1 (A = Na, K, and Cs; 3¯n¯6). Except for recent works by Kobayashi et al 69 and Yamamoto et al, 70,71 where one-step synthesis of TiO 2 (mC) was successfully achieved by a hydrothermal method employing a water-soluble peroxooxoglycolato Ti-complex, many recent reports of the synthesis of TiO 2 (mC) 40,7277 basically rely upon the three-step procedure established by Tournoux and Davies, a representative of which is described as follows in the case of sodium titanates.…”

Synthesis and development of titania with controlled structures

“…15) TiO 2 (B) was obtained as a single phase from the hydrothermal treatment of a glycolate titanium complex in the presence of the proper amount of sulfuric acid. 33) Introducing a large amount of sulfuric acid produced a single phase of anatase. TiO 2 (B) was not formed using other inorganic acids such as hydrochloric or nitric acid.…”

Photocatalytic activity of nanocrystalline TiO2(B) synthesized from titanium glycolate complex by hydrothermal method

“…We reported direct synthesis of TiO2(B) by a hydrothermal treatment without formation of intermediates such as Na2Ti3O7 and H2Ti3O7. 12) In the proposed method titanium complex with glycolic acid was used as a starting reagent. Glycolic acid, which is also known as an easily accessible food product, coordinates Ti 4+ ion together with O 2-and O2 2-ions to form a water-soluble titanium glycolate complex.…”