Synthetic of Uniform Spindle-Type Titania Particles by the Gel–Sol Method

doi:10.1006/jcis.1997.5037

Journal of Colloid and Interface Science

Volume 193, Issue 1, 1 September 1997, Pages 140-143

https://doi.org/10.1006/jcis.1997.5037 Get rights and content

Abstract

Uniform spindle-type titania (TiO₂) particles were prepared by a novel gel–sol method. A mixed solution of titanium(IV) isopropoxide and triethanolamine at molar ratio 1:2 prepared in a drybox was mixed with doubly distilled water to make the final concentration of titanium(IV) 0.50 mol dm⁻³. The mixture was further mixed with an equal volume of 2.0 mol dm⁻³ammonia solution, and the resulting solution was aged for 24 h at 100°C. By this aging a highly viscous gel was formed, but there was no sign of nucleation of titania at this stage. The gel was then aged at 140°C for 3 days to nucleate and grow the titania particles. The gel network formed in the first aging played a decisive role in the second aging to produce the uniform particles of titania, as a reservoir of the metal ions to lower the supersaturation for preventing extensive nucleation and as an anticoagulant fixing the growing particles in the matrix. The product was identified by XRD as anatase particles elongated in the direction of thec-axis. The aspect ratio, as well as the size of the resulting particles, was reduced as the concentration of ammonia was decreased.

References (18)

E. Matijević et al.
J. Colloid Interface Sci.
(1977)
T. Sugimoto et al.
J. Colloid Interface Sci.
(1992)
T. Sugimoto et al.
J. Colloid Interface Sci.
(1993)
T. Sugimoto et al.
Colloids Surf. A
(1993)
T. Sugimoto et al.
Colloids Surf. A
(1993)
T. Sugimoto et al.
J. Colloid Interface Sci.
(1993)
T. Sugimoto et al.
Colloid Surf. A
(1996)
T. Sugimoto et al.
J. Colloid Interface Sci.
(1995)

There are more references available in the full text version of this article.

Cited by (116)

Synthesis of concentrated colloidal dispersion of zinc-based spinel nanoparticles via liquid-phase crystallization from “double-hydroxide-like” metal hydroxides
2024, Colloids and Surfaces A: Physicochemical and Engineering Aspects
We demonstrate a liquid-phase crystallization of interdispersed metal hydroxides nanoparticles (NPs) (diameter < 10 nm), toward the versatile syntheses of highly concentrated colloidal dispersions of spinel oxides. ZnGa₂O₄ was chosen as a representative system to demonstrate our strategy. Heating of precursory wetgels of hydroxide NPs, interdispersed in a quasi-double-hydroxide-state, induced the crystallization at 60–80 °C into ZnGa₂O₄ NPs with a size of single nanometer. X-ray absorption fine structure (XAFS) analysis reveals that octahedrally coordinated Zn²⁺ in the hydroxide NPs decreased as the result of the crystallizations, and the amount of tetrahedrally coordinated Zn²⁺ increased. By the chelation of acetylacetone (acac) to tetrahedrally coordinated zinc species in crystalline oxides NPs, deflocculation of the wetgel was induced and then acac worked as a dispersion stabilizer. The present method can be also applied to ZnAl₂O₄ and ZnFe₂O₄ NPs, allowing to yield the colloidal dispersions of spinel oxides NPs with a size of single nanometers in diameter with high dispersion stability (over 1 week) under highly concentrated conditions (ca. 20–40 g/L).
Polystyrene/TiO<inf>2</inf> nanocomposite coating for strength and toughness enhancement of aluminum alloy 2024–T3 in accelerated stress corrosion cracking
2021, Progress in Organic Coatings
Citation Excerpt :
Because of the modification, the formulas from the ASTM E1820 Standard for determining the mechanical response of the C(T) specimens should be accordingly modified as presented in the Results section. The TiO2 nanoparticles were synthesized per the gel-sol method [24,25]. The starting precursor was prepared by mixing titanium(IV) isopropoxide (TIPO) with triethanolamine (TEOA) at a molar ratio of TIPO: TEOA 1:2.
The polystyrene/TiO₂ nanocomposite coating is evaluated for reducing the susceptibility of aluminum alloy AA2024-T3 to stress corrosion cracking (SCC). The as-synthesized titania nanoparticles of aspect ratio (AR) 1, 2, and 4 are individually loaded at 25 wt% to the acetone-dissolved polystyrene (PS) to make the nanocomposites. Coated compact tension specimens are tested under accelerated SCC testing that combines the constant displacement rate equivalent to 10⁻⁷ s⁻¹ and 3.5 wt% NaCl solution dripped at the crack tip. The load and crack-mouth opening displacement of each specimen are recorded and analyzed to determine the indices to the mechanical ductility, strength, toughness, and fracture toughness. The PS/TiO₂ AR1 coated specimens exhibit the least SCC susceptibility, with a relatively high fracture toughness of 55 MPa-m^1/2 and more than 60 h of lifetime without apparent cracking under the SCC testing. Intriguingly, the PS-coated specimens perform similarly well. The results are explained by an SCC failure mechanism that considers the complex interaction among the agglomerated nanoparticles, polystyrene matrix, and the substrate in various aspects. The mechanism suggests that the nanocomposite coating with a higher yield strength and less permeability performs better. The highly loaded nanoparticles such as 25 wt% used herein make the nanocomposite only more marginally yieldable than polystyrene, but undesirably introduce morphological and electrochemical defects that count against the SCC susceptibility improvement.
Mesocrystalline Cr and Sb-codoped anatase visible-light-driven photocatalyst
2018, Ceramics International
We report on the synthesis, characterization and visible-light-driven photocatalytic activity of mesocrystalline Cr- and Sb-codoped anatase nanoparticles. Discrete and morphologically well-defined assemblies of anatase nanoparticles sized below 100 nm × 50 nm were prepared by hydrothermal aging of aqueous solutions containing titanium alkoxide, chromium acetylacetonate, antimony acetate and triethanolamine (TEOA) as stabilizer.
The as-prepared and TEOA-free doped nanoparticles showed similar crystallographic parameters and spectroscopic features. The incorporation of Cr and Sb dopant cations into the anatase nanoparticles was evaluated by Rietveld refinement of X-ray diffraction patterns and several spectroscopic characterization techniques. Interestingly, the morphology of the final particles was strongly dependent on the dopant amount. On increasing the nominal dopant load the spheroidal cross section changed to ellipsoidal (elongated) and the nanoparticles exhibited large pore volume and high surface area values. Transmission and scanning electron microscopies, TEM and SEM, respectively also revealed that the hydrothermally prepared nanoparticles were built of smaller primary nanoparticles sized around 4 nm. High resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) revealed the mesocrystalline nature of the synthesized nanoparticles. UV–Vis diffuse reflectance (DR) and X-ray photoelectron (XPS) spectra indicated that the oxidation numbers of antimony and chromium codoped into TiO₂ are 5+ and 3+, respectively.
The results on the photocatalytic activity of the prepared photocatalyst nanoparticles built of discrete assemblies of very small nanoparticles of Cr- and Sb-codoped TiO₂ anatase proved their high efficiency in the degradation of MO (methyl orange) dye under visible light irradiation.
Anatase TiO<inf>2</inf> powder: Synthesis, characterization and application for photocatalytic degradation of 3, 4-dihydroxy benzoic acid
2018, Optik
White, crystalline TiO₂ powder has been synthesized in a large scale by a single-step chemical reaction between oleic acid and titanium (IV) isopropoxide. The crystal structure of the powder was evaluated by X-ray diffraction and transmission electron microscopy and the BET surface area was estimated by nitrogen adsorption-desorption technique. The structure of TiO₂ strongly depends on the synthesis temperature. The powder synthesized at 400 °C is purely anatase, that prepared at 600 °C is mainly rutile and those synthesized at 450 °C, 500 °C and 550 °C are mixtures of anatase and rutile TiO₂. The powder synthesized at 450 °C contains 68% anatase and 32% rutile TiO₂ with an effective surface area of 78 m² g⁻¹. The photocatalytic activity of the above powder has been studied with photodegradation of commercial 3, 4-dihydroxy benzoic acid. The recyclability of the catalyst has been tested after heat treatment of the used TiO₂.
Effect of hydroxy and carboxy groups on anisotropic growth of rutile-type titania under hydrothermal conditions
2017, Journal of Asian Ceramic Societies
Control of crystal growth leads to highly functional materials with desired morphologies. In this study, the relationship between select additives and the crystal growth of rutile-type titania under hydrothermal conditions using α-hydroxy acids, carboxylic acids, or alcohols as additives was systematically investigated. Without additives, rod-like rutile crystals with average dimensions of 295 nm × 67 nm were formed. Acceleration of the crystal growth was observed and the aspect ratios of the resulting rod-like crystals were found to increase in the presence of the additives. Alcohols promoted crystal growth along the c-axis, but not in the direction to perpendicular to [001]. Carboxylic acids accelerated the overall crystal growth and this increase was more enhanced along the c-axis than that along others. Both effects were observed using α-hydroxy acids. In addition, the present results implied that the size of the hydrocarbon groups in alcohols and α-hydroxy acids appeared to be related to the acceleration of crystal growth along the c-axis. Hydroxy groups may reduce the surface energy of the crystal facets perpendicular to the c-axis by their adsorption on those facets, resulting in the formation of rod-like crystals with high aspect ratio.
Fabrication of anatase TiO<inf>2</inf> tapered tetragonal nanorods with designed {100}, {001} and {101} facets for enhanced photocatalytic H<inf>2</inf> evolution
2017, International Journal of Hydrogen Energy
In this study, anatase TiO₂ nanorods with exposed high-energy {100} and {001} facets and low-energy {101} facets were fabricated in the presence of surfactants cetyltrimethylammonium bromide, didecyldimethylammonium bromide, and ammonia via a facile hydrothermal method without the erosive reagent hydrofluoric acid. The particle size and morphology were mainly tuned by regulating the hydrothermal temperature. When the temperature was increased from 150 °C to 180 °C and 200 °C, the length of the nanorods decreased from 700-1000 nm to 400–500 nm and 100–200 nm, respectively. Concurrently, the edges and tops of the truncated tetragonal pyramid of the TiO₂ nanorods became blurry and flattened. The synthesized typical TiO₂ nanorods were then used as photocatalysts, and their performance during the direct generation of H₂ from water was evaluated. The TiO₂ nanorods obtained at 150 °C successfully produced high amounts of H₂ evolution (281.36 μmol) in the presence of methanol as a sacrificial agent under ultraviolet light irradiation for 4 h. The outstanding photocatalytic activity of the nanorods was mainly ascribed to the formation of surface heterojunctions in the edges and corners between adjacent high-energy {001} or {100} facets and low-energy {101} facets. The formed heterojunctions could facilitate charge separation through preferential carrier flow toward the specific facets.

View all citing articles on Scopus

: Presented in part at the 49th Symposium on Colloid and Interface Chemistry, Hachioji, Japan, September 19–21, 1996.

²: To whom correspondence should be addressed.

View full text

LETTER TO THE EDITORSynthetic of Uniform Spindle-Type Titania Particles by the Gel–Sol Method

Abstract

J. Colloid Interface Sci.

J. Colloid Interface Sci.

J. Colloid Interface Sci.

Colloids Surf. A

Colloids Surf. A

J. Colloid Interface Sci.

Colloid Surf. A

J. Colloid Interface Sci.

LETTER TO THE EDITOR
Synthetic of Uniform Spindle-Type Titania Particles by the Gel–Sol Method