Microstructural Analysis of Au/TiO2-SBA-15 Nanocomposite

2014 ◽  
Vol 20 (4) ◽  
pp. 1001-1007 ◽  
Author(s):  
Takashi Gondo ◽  
Kenji Kaneko ◽  
Takeshi Nishiyama ◽  
Kazuhiro Yamada ◽  
Zineb Saghi ◽  
...  
Keyword(s):  
Pore Size ◽  
High Surface ◽  
Sol Gel ◽  
Microstructural Analysis ◽  
High Surface Area ◽  
Strong Interactions ◽  
Synthesis Methods ◽  
Oxide Supports ◽  
Catalytic Activities ◽  
Size And Morphology

AbstractProperties of gold nanoparticles (AuNPs) are very different from bulk gold, in particular, highly dispersed AuNPs exhibit high catalytic activities on metal oxide supports. Catalytic activities of AuNPs are strongly dependent on: (i) size and morphology; (ii) synthesis methods; (iii) nature of the support; (iv) interaction between AuNPs and the support; and (v) oxidation state of AuNPs in the synthesized catalysts. A goal is to maintain the size and to prohibit aggregation of AuNPs, since aggregations deteriorate catalytic activities. Some strong interactions are therefore required between AuNPs and their supports to prevent the movement of AuNPs. SBA-15 is a promising material for the support of AuNPs since it has ordered two-dimensional hexagonal pore channels, uniform pore size ranging from 5 to 30 nm, narrow pore size distribution, thick amorphous walls ranging from 3 to 6 nm, and high surface area. In this study, SBA-15, TiO2-SBA-15 and TiO2-SBA-15-AuNP nanocomposites were synthesized by the sol-gel method and microstructural characterizations were carried out by both X-ray diffraction analysis and electron microscopy.

scholarly journals Mesoporous Titanium Dioxide: Synthesis and Applications in Photocatalysis, Energy and Biology

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1910 ◽  
Author(s):  
Ben Niu ◽  
Xin Wang ◽  
Kai Wu ◽  
Xianru He ◽  
Rui Zhang
Keyword(s):  
Titanium Dioxide ◽  
Mesoporous Materials ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Mesoporous Tio2 ◽  
Synthesis Methods ◽  
New Energy ◽  
Mesoporous Titanium Dioxide ◽  
New Research

Mesoporous materials are materials with high surface area and intrinsic porosity, and therefore have attracted great research interest due to these unique structures. Mesoporous titanium dioxide (TiO2) is one of the most widely studied mesoporous materials given its special characters and enormous applications. In this article, we highlight the significant work on mesoporous TiO2 including syntheses and applications, particularly in the field of photocatalysis, energy and biology. Different synthesis methods of mesoporous TiO2—including sol–gel, hydrothermal, solvothermal method, and other template methods—are covered and compared. The applications in photocatalysis, new energy batteries and in biological fields are demonstrated. New research directions and significant challenges of mesoporous TiO2 are also discussed.

The Influence of TiO2 Photoanode Morphology for Scattering Enhanced Properties of Dye-Sensitized Solar Cell

2013 ◽  
Vol 667 ◽  
pp. 425-434 ◽  
Author(s):  
Mohd Hanapiah Abdullah ◽  
Ismail Lyly Nyl ◽  
Mohamed Zahidi Musa ◽  
Mohamad Rusop Mahmood
Keyword(s):  
Pore Size ◽  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Tio2 Electrode ◽  
Pore Size Distributions ◽  
Tio2 Sol ◽  
Micron Size ◽  
Enhanced Properties

Effect of PEG on the TiO2 electrode morphology for scattering enhanced properties of the modified paste containing TiO2 sol-gel mixed with Degussa P-25 were investigated. The high surface area of the scattering centres in this study were formed by using nano size particles ascribed from TiO2 sol-gel while the sub-micron size particles were utilized from the reaction of PEG on the Degussa P-25 particles. The pore size distributions were tailored by varying the PEG content in the fabricated electrodes. Higher surface area with adequate pore size of P30 electrode has contributed to higher JSC and efficiency (η) of 11.35450 mA/cm2 and 2.479624 %, respectively. Photocurrent action spectra of IPCE of the DSSC exhibit the maximum of 42 % at 550 nm correspond to the P30 TiO2 electrode. Overall results suggest that the incorporation of TiO2 sol-gel component mixed with TiO2 paste derived from commercially available nanopowder could enhance surface area as well as serves for better light scattering effect, while PEG addition creates adequate pore size distribution to maximize the dye adsorbed on the TiO2 electrode.

Structure and composition of metal particles in Pt-Sn/Al2O3 bimetallic catalysts

1990 ◽  
Vol 48 (4) ◽  
pp. 278-279
Author(s):  
A. Sachdev ◽  
J. Schwank
Keyword(s):  
Bimetallic Catalysts ◽  
Bimetallic Catalyst ◽  
Size Structure ◽  
High Surface ◽  
High Surface Area ◽  
Metal Particles ◽  
Alloy Formation ◽  
Particle Size Range ◽  
Oxide Supports ◽  
Petroleum Fractions

Platinum - tin bimetallic catalysts have been primarily utilized in the chemical industry in the catalytic reforming of petroleum fractions. In this process the naphtha feedstock is converted to hydrocarbons with higher octane numbers and high anti-knock qualities. Most of these catalysts contain small metal particles or crystallites supported on high surface area insulating oxide supports. The determination of the structure and composition of these particles is crucial to the understanding of the catalytic behavior. In a bimetallic catalyst it is important to know how the two metals are distributed within the particle size range and in what way the addition of a second metal affects the size, structure and composition of the metal particles. An added complication in the Pt-Sn system is the possibility of alloy formation between the two elements for all atomic ratios.

scholarly journals Bifunctional acid–base mesoporous silica@aqueous miscible organic-layered double hydroxides

RSC Advances ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 3749-3754 ◽  
Author(s):  
Hongri Suo ◽  
Haohong Duan ◽  
Chunping Chen ◽  
Jean-Charles Buffet ◽  
Dermot O'Hare
Keyword(s):  
Mesoporous Silica ◽  
Pore Size ◽  
Layered Double Hydroxides ◽  
High Surface ◽  
High Surface Area ◽  
Core Shell ◽  
Acid Base ◽  
Double Hydroxides ◽  
Hierarchical Morphology ◽  
Size And Structure

Core@shell materials which exhibit hierarchical morphology with ultra high surface area and controllable pore size and structure have been synthesised.

High-Surface-Area Alumina-Silica Nanocatalysts Prepared by a Hybrid Sol-Gel Route Using a Boehmite Precursor

2010 ◽  
Vol 93 (12) ◽  
pp. 4047-4052 ◽  
Author(s):  
Padmaja Parameswaran Nampi ◽  
Padmanabhan Moothetty ◽  
Wilfried Wunderlich ◽  
Frank John Berry ◽  
Michael Mortimer ◽  
...  
Keyword(s):  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area

Synthesis and structural characteristics of high surface area TiO2 aerogels by ultrasonic-assisted sol–gel method

2018 ◽  
Vol 29 (7) ◽  
pp. 075702 ◽  
Author(s):  
Feng Qingge ◽  
Cai Huidong ◽  
Lin Haiying ◽  
Qin Siying ◽  
Liu Zheng ◽  
...  
Keyword(s):  
Surface Area ◽  
Structural Characteristics ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Gel Method ◽  
Sol Gel Method ◽  
Ultrasonic Assisted

Texture Evaluation of Sol-Gel Derived Mesoporous Bioactive Glass

2013 ◽  
Vol 284-287 ◽  
pp. 230-234
Author(s):  
Yu Jen Chou ◽  
Chi Jen Shih ◽  
Shao Ju Shih
Keyword(s):  
Surface Area ◽  
Calcination Temperature ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Nitrogen Adsorption ◽  
Bioactive Glasses ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Adsorption Desorption

Recent years mesoporous bioactive glasses (MBGs) have become important biomaterials because of their high surface area and the superior bioactivity. Various studies have reported that when MBGs implanted in a human body, hydroxyl apatite layers, constituting the main inorganic components of human bones, will form on the MBG surfaces to increase the bioactivity. Therefore, MBGs have been widely applied in the fields of tissue regeneration and drug delivery. The sol-gel process has replaced the conventional glasses process for MBG synthesis because of the advantages of low contamination, chemical flexibility and lower calcination temperature. In the sol-gel process, several types of surfactants were mixed with MBG precursor solutions to generate micelle structures. Afterwards, these micelles decompose to form porous structures after calcination. Although calcination is significant for contamination, crystalline and surface area in MBG, to the best of the authors’ knowledge, only few systematic studies related to calcination were reported. This study correlated the calcination parameters and the microstructure of MBGs. Microstructure evaluation was characterized by transmission electron microscopy and nitrogen adsorption/desorption. The experimental results show that the surface area and the pore size of MBGs decreased with the increasing of the calcination temperature, and decreased dramatically at 800°C due to the formation of crystalline phases.

Influence of Pore Size on Enzymes Adsorption in Mesostructure Cellular Foams (MCFs)

2009 ◽  
Vol 610-613 ◽  
pp. 109-113
Author(s):  
Wei Na ◽  
Qi Wei ◽  
Ze Chang Zou ◽  
Zhi Hong Wang ◽  
Qun Yan Li ◽  
...  
Keyword(s):  
Pore Size ◽  
High Surface ◽  
High Surface Area ◽  
Window Size ◽  
Molecular Size ◽  
Suitable Host ◽  
Small Window ◽  
Cellular Foams ◽  
Silica Materials ◽  
Large Pore Volume

Mesoporous silica materials are attractive candidates for enzymes immobilization due to their high surface area, tunable pore size, large pore volume and biocompatibility. In this work, two different enzymes, papain, a small globular enzyme with molecular diameter of 3.6nm, and catalase, a relatively larger enzyme with molecular diameter of 10.4nm were introduced into the pores of siliceous mesostructed cellular foams (MCFs) that had a large cellular pores of 29nm and a small window size of 12nm, respectively. The amount of adsorbed enzymes was found to be dependent on the molecular size of enzymes. The amount of adsorbed catalase was more than two times that of adsorbed papain, suggesting that MCFs with large pores is a suitable host for large enzymes adsorption. The blocking of pores which resulted from aggregation of enzymes in the windows of MCFs and the higher leaching of enzymes form MCFs may be the reason of lower papain adsorption capacity in MCFs.

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