Low-Temperature Synthesis of Soluble and Processable Organic-Capped Anatase TiO₂ Nanorods

Abstract

We demonstrate the controlled growth of high aspect ratio anatase TiO2 nanorods by hydrolysis of titanium tetraisopropoxide (TTIP) in oleic acid (OLEA) as surfactant at a temperature as low as 80 degrees C. Chemical modification of TTIP by OLEA is proven to be a rational strategy to tune the reactivity of the precursor toward water. The most influential factors in shape control of the nanoparticles are investigated by simply manipulating their growth kinetics. The presence of tertiary amines or quaternary ammonium hydroxides as catalysts is essential to promote fast crystallization under mild conditions. The novelty of the present approach relies on the large-scale production of organic-capped TiO2 nanocrystals to which standard processing of colloidal nanocrystals, such as surface ligand exchange, can be applied for the first time. Concentrated colloidal titania dispersions can be prepared for a number of fundamental studies in homogeneous solutions and represent a new source of easily processable oxide material for many technological applications.

Strong Room-Temperature Ferromagnetism in Co2+-Doped TiO2 Made from Colloidal Nanocrystals

“…Preferential growth of pure TiO 2 nanocrystals along the c-direction has been reported previously, 22 and the ellipticity observed in Figure 2A indicates that it should be possible to generate similarly anisotropic nanocrystals of this DMS from solution under proper experimental conditions. Although TiO 2 nanocrystals are susceptible to aggregation, the lack of noticeable visible-light scattering by the NC1 suspension suggests that little aggregation has occurred in this case.…”

Synthetic versatility of nanoparticles: A new, rapid, one-pot, single-step synthetic approach to spherical mesoporous (metal) oxide nanoparticles using supercritical alcohols

“…The absorption peaks , also observed for the particles obtained at 300 and 400 °C, indicated that the NPs contained carboxylate (COO -) groups (Fig. 6) [65][66][67]. In addition, the weight loss of the MARIMO TiO 2 NPs synthesized in the presence of phthalic acid at 300 and 400 °C was 11.5% and 12.0%, respectively, as determined via TG analysis under a N 2 gas flow, indicating that the MARIMO TiO 2 NPs contain at most ca.…”

Homogeneous coating of photonic macroporous oxides with inorganic nanocrystals

“…Nanocrystals of titanium dioxide (nan-TiO2) were prepared using a hydrothermal method with oleic acid as the surface stabilising ligand. 13 Transmission electron microscopy (TEM) ( Figure 3a) and PXRD showed that the nanoparticles are on average 8.9 ± 1 nm in diameter, single crystalline and exhibit the anatase phase. Combustion analysis gave an oleic acid:TiO2 molar ratio of 1.25:1 and the nanocrystals can be dispersed in common organic solvents to give optically transparent solutions.…”