Solvothermal synthesis of nanocrystalline TiO2 in toluene with surfactant

Kim, Chung-Sik; Moon, Byung Kee; Park, Jong-Ho; Choi, Byung Chun; Seo, Hyun‐Ju

doi:10.1016/s0022-0248(03)01468-4

Cited by 118 publications

(53 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted that, although the TiO 2 nanoparticles were prepared at room temperature and without any postsynthesis (calcination) treatment, the particles exhibit a remarkable level of purity in the crystalline phase. This is in sharp contrast to a number of earlier studies where the TiO 2 nanoparticles exhibited poor crystallinity and high dispersity in size (36)(37)(38)(39). Additionally, the formation of snowmanlike heterodimers rather than core-shell nanostructures might be ascribed to the asymmetrical surface structures of the gold Janus nanoparticles that provide directional growth of the semiconductor component.…”

Section: Resultscontrasting

confidence: 80%

Janus Nanostructures Based on Au−TiO₂ Heterodimers and Their Photocatalytic Activity in the Oxidation of Methanol

Pradhan

Ghosh

Chen

2009

ACS Appl. Mater. Interfaces

121

View full text Add to dashboard Cite

Au-TiO 2 snowman-like heterodimer nanoparticles were prepared by a surface sol-gel process based on gold Janus nanoparticles whose surface-protecting monolayers consisted of a hemisphere of hydrophobic 1-hexanethiolates and the other of hydrophilic 2-(2-mercaptoethoxy)ethanol. Transmission electron microscopic measurements showed that the resulting TiO 2 nanoparticles (diameter 6 nm) exhibited well-defined lattice fringes that were consistent with the (101) diffraction planes of anatase TiO 2 . The heterodimer nanoparticles displayed apparent photoluminescence that was ascribed to electronic transitions involving trap states of TiO 2 particles, and the photocatalytic activity was manifested by the oxidative conversion of methanol into formaldehyde, which was detected quantitatively by the Nash method. The enhanced photocatalytic performance, as compared to that of the TiO 2 nanoparticles alone, was ascribed to the charge separation of photogenerated electrons and holes at the Au-TiO 2 interface that was facilitated by the close proximity of the gold nanoparticles. These results suggested that (i) there were at least two possible pathways for photogenerated electrons at the TiO 2 conduction band, decay to the trap states and transfer to the gold nanoparticles, and (ii) energy/electron transfer from the trap states to gold nanoparticles was less efficient. In essence, this study showed that the snowmanlike heterodimers might be exploited as a homogeneous photocatalytic system for the preparation of functional molecules and materials.

show abstract

Section: Resultscontrasting

confidence: 80%

Janus Nanostructures Based on Au−TiO₂ Heterodimers and Their Photocatalytic Activity in the Oxidation of Methanol

Pradhan

Ghosh

Chen

2009

ACS Appl. Mater. Interfaces

121

View full text Add to dashboard Cite

show abstract

“…Nowadays, nonaqueous synthesis approaches have become a valuable alternative to aqueous systems and the family of metal oxide nanoparticles synthesized by nonhydrolytic reaction routes is growing rapidly, [74][75][76][77] including TiO 2 , [78][79][80][81][82][83][84][85] FeO x , [86][87][88][89][90][91][92][93][94][95][96][97][98][99] MnO, [86,90,[100][101][102][103][104] Mn 3 O 4 , [84,100,105] CeO 2 , [106] CuO x , [105,107] Cr 2 O 3 , [90] Co 3 O 4 , [90,108] CoO, [105,109] NiO, [90,102,110] ReO 3 , [111] ZrO 2 , [112,…”

Section: Nonaqueous Sol-gel Chemistry For Metal Oxide Synthesismentioning

confidence: 99%

Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles

Niederberger

Garnweitner

2006

Chemistry A European J

460

457

View full text Add to dashboard Cite

Nonaqueous-solution routes to metal oxide nanoparticles are a valuable alternative to the known aqueous sol-gel processes, offering advantages such as high crystallinity at low temperatures, robust synthesis parameters and ability to control the crystal growth without the use of surfactants. In the first part of the review we give a detailed overview of the various solution routes to metal oxides in organic solvents, with a strong focus on surfactant-free processes. In most of these synthesis approaches, the organic solvent plays the role of the reactant that provides the oxygen for the metal oxide, controls the crystal growth, influences particle shape, and, in some cases, also determines the assembly behavior. We have a closer look at the following reaction systems in this order: 1) metal halides in alcohols, 2) metal alkoxides, acetates, and acetylacetonates in alcohols, 3) metal alkoxides in ketones, and 4) metal acetylacetonates in benzylamine. All these systems offer some peculiarities with respect to each other, providing many possibilities to control and tailor the particle size and shape, as well as the surface and assembly properties. In the second part we present general mechanistic principles for aqueous and nonaqueous sol-gel processes, followed by the discussion of reaction pathways relevant for nanoparticle formation in organic solvents. Depending on the system several mechanisms have been postulated: 1) alkyl halide elimination, 2) elimination of organic ethers, 3) ester elimination, 4) C--C bond formation between benzylic alcohols and alkoxides, 5) ketimine and aldol-like condensation reactions, 6) oxidation of metal nanoparticles, and 7) thermal decomposition methods.

show abstract

“…Important characteristics such as the ionic product density, thermal conductivity, viscosity, heat capacity and the dielectric constant are all highly pressure and temperature dependent and by tuning the synthesis parameters, specific solvent properties can be obtained. Feng et al [44] produced TiO 2 nanorods by treating titanium tetrachloride solution saturated with sodium chloride at 160°C for 2 h. Kim et al [45] used the solvothermal method to prepare TiO 2 of good quality without the use of surfactants.…”

Section: Hydro/solvothermal Methodsmentioning

confidence: 99%

Synthetic Methods for Titanium Dioxide Nanoparticles: A Review

Nyamukamba¹,

Okoh²,

Mungondori³

et al. 2018

Titanium Dioxide - Material for a Sustainable Environment

View full text Add to dashboard Cite

Titanium dioxide (TiO 2 ) semiconductor nanoparticles are one kind of important and promising photocatalysts in photocatalysis because of their unique optical and electronic properties. Their properties, which are determined by the preparation method, are very crucial in photocatalysis. In this chapter, an overview was carried out on the different methods that are used or have been used to prepare titanium dioxide nanoparticles. There are various methods that can be used to synthesize TiO 2 and the most commonly used methods include sol-gel process, chemical vapor deposition (CVD) and hydrothermal method among others. This review will focus on selected preparation methods of titanium dioxide photocatalyst.

show abstract

Solvothermal synthesis of nanocrystalline TiO2 in toluene with surfactant

Cited by 118 publications

References 26 publications

Janus Nanostructures Based on Au−TiO₂ Heterodimers and Their Photocatalytic Activity in the Oxidation of Methanol

Janus Nanostructures Based on Au−TiO₂ Heterodimers and Their Photocatalytic Activity in the Oxidation of Methanol

Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles

Synthetic Methods for Titanium Dioxide Nanoparticles: A Review

Contact Info

Product

Resources

About

Solvothermal synthesis of nanocrystalline TiO2 in toluene with surfactant

Cited by 118 publications

References 26 publications

Janus Nanostructures Based on Au−TiO2 Heterodimers and Their Photocatalytic Activity in the Oxidation of Methanol

Janus Nanostructures Based on Au−TiO2 Heterodimers and Their Photocatalytic Activity in the Oxidation of Methanol

Organic Reaction Pathways in the Nonaqueous Synthesis of Metal Oxide Nanoparticles

Synthetic Methods for Titanium Dioxide Nanoparticles: A Review

Contact Info

Product

Resources

About

Janus Nanostructures Based on Au−TiO₂ Heterodimers and Their Photocatalytic Activity in the Oxidation of Methanol

Janus Nanostructures Based on Au−TiO₂ Heterodimers and Their Photocatalytic Activity in the Oxidation of Methanol