Fabrication of Three-Dimensionally Ordered Macro-/Mesoporous Titania Monoliths by a Dual-Templating Approach

2011 ◽  
Vol 1352 ◽  
Author(s):  
Zhiyan Hu ◽  
Zhongjiong Hua ◽  
Shaohua Cai ◽  
Jianfeng Chen ◽  
Yushan Yan ◽  
...  
Keyword(s):  
Colloidal Crystal ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Titanium Tetraisopropoxide ◽  
Structure Directing Agent ◽  
Pluronic P123 ◽  
Surfactant Templating ◽  
Mesopore Structure ◽  
Colloidal Crystal Templating

ABSTRACTThree-dimensionally ordered macro-/mesoporous (3DOM/m) TiO2 monoliths were fabricated by a dual-templating synthesis approach employing a combination of both colloidal crystal templating (hard-templating) and surfactant templating (soft-templating) techniques. Titania precursor, consisting of amphiphilic triblock copolymer Pluronic P123 as a mesopore-structure-directing agent and titanium tetraisopropoxide as a titanium source, was infiltrated into the void spaces of the poly(methyl methacrylate) (PMMA) colloidal crystal monolith. Subsequent thermal treatment produced 3DOM/m TiO2 monolith. The macropore walls of the prepared 3DOM/m TiO2 exhibit a well-defined mesoporous structure with narrow pore size distribution, and the mesopore walls are composed of nanocrystalline anatase TiO2. The material also shows a high surface area (171 m2/g), and large pore volume (0.402 cm3/g).

Hard-templating synthesis and enhanced photocatalysis of mesoporous titanium dioxides nanoparticles

2018 ◽  
Vol 11 (04) ◽  
pp. 1850077 ◽  
Author(s):  
K. L. Jin ◽  
X. J. Chen ◽  
J. C. Xu ◽  
Y. S. Huang ◽  
Y. B. Han ◽  
...  
Keyword(s):  
Surface Area ◽  
Anatase Phase ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Photocatalytic Decomposition ◽  
Titanium Dioxides ◽  
Decomposition Efficiency ◽  
Templating Synthesis ◽  
Mb Adsorption

Mesoporous titanium dioxides nanoparticles (TiO2 NPs) were synthesized using activated carbon (AC) as templates after the decomposition of AC. All results indicated that TiO2 NPs with the small grain size presented the anatase phase structure. Mesoporous TiO2 NPs showed the high surface area and the surface area decreased with the TiO2 content. The removal of methylene blue (MB) indicated that the photocatalytic decomposition efficiency of mesoporous TiO2 NPs increased up to 92% for three-times doping with the TiO2 content, and then decreased. This should be attributed to the synergistic effect from the MB adsorption of mesoporous-structure and the photocatalysis of TiO2 NPs. Therefore, the higher MB concentration near TiO2 NPs from the mesoporous-structure increased the touch chance and the MB photocatalytic decomposition was promoted greatly.

scholarly journals A Structural Comparison of Ordered and Non-Ordered Ion Doped Silicate Bioactive Glasses

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 992
Author(s):  
Seray Schmitz ◽  
Ana M. Beltrán ◽  
Mark Cresswell ◽  
Aldo R. Boccaccini
Keyword(s):  
Metal Ion ◽  
Sol Gel ◽  
Glass Network ◽  
Textural Properties ◽  
Mesoporous Structure ◽  
Structure Directing Agent ◽  
Surface Areas ◽  
Pluronic P123 ◽  
Gel Glasses ◽  
The One

One of the key benefits of sol-gel-derived glasses is the presence of a mesoporous structure and the resulting increase in surface area. This enhancement in textural properties has a significant effect on the physicochemical properties of the materials. In this context the aim of this study was to investigate how sol-gel synthesis parameters can influence the textural and structural properties of mesoporous silicate glasses. We report the synthesis and characterization of metal ion doped sol-gel derived glasses with different dopants in the presence or absence of a surfactant (Pluronic P123) used as structure-directing templating agent. Characterization was done by several methods. Using a structure directing agent led to larger surface areas and highly ordered mesoporous structures. The chemical structure of the non-ordered glasses was modified to a larger extent than the one of the ordered glasses due to increased incorporation of dopant ions into the glass network. The results will help to further understand how the properties of sol-gel glasses can be controlled by incorporation of metal dopants, in conjunction with control over the textural properties, and will be important to optimize the properties of sol-gel glasses for specific applications, e.g., drug delivery, bone regeneration, wound healing, and antibacterial materials.

scholarly journals Characterization of Residual Biomasses and Its Application for the Removal of Lead Ions from Aqueous Solution

2019 ◽  
Vol 9 (21) ◽  
pp. 4486 ◽  
Author(s):  
Candelaria Tejada-Tovar ◽  
Angel Darío Gonzalez-Delgado ◽  
Angel Villabona-Ortiz
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
High Surface ◽  
High Surface Area ◽  
Freundlich Isotherm ◽  
Mesoporous Structure ◽  
Isotherm Models ◽  
Solution Ph ◽  
Batch Mode ◽  
Suitable Alternative

The removal of water pollutants has been widely addressed for the conservation of the environment, and novel materials are being developed as adsorbent to address this issue. In this work, different residual biomasses were employed to prepare biosorbents applied to lead (Pb(II)) ion uptake. The choice of cassava peels (CP), banana peels (BP), yam peels (YP), and oil palm bagasse (OPB) was made due to the availability of such biomasses in the Department of Bolivar (Colombia), derived from agro-industrial activities. The materials were characterized by ultimate and proximate analysis, Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller analysis (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS) in order to determine the physicochemical properties of bioadsorbents. The adsorption tests were carried out in batch mode, keeping the initial metal concentration at 100 ppm, temperature at 30 °C, particle size at 1 mm, and solution pH at 6. The experimental results were adjusted to kinetic and isotherm models to determine the adsorption mechanism. The remaining concentration of Pb(II) in solution was measured by atomic absorption at 217 nm. The functional groups identified in FTIR spectra are characteristic of lignocellulosic materials. A high surface area was found for all biomaterials with the exception of yam peels. A low pore volume and size, related to the mesoporous structure of these materials, make these bioadsorbents a suitable alternative for liquid phase adsorption, since they facilitate the diffusion of Pb(II) ions onto the adsorbent structure. Both FTIR and EDS techniques confirmed ion precipitation onto adsorbent materials after the adsorption process. The adsorption tests reported efficiency values above 80% for YP, BP, and CP, indicating a good uptake of Pb(II) ions from aqueous solution. The results reported that Freundlich isotherm and pseudo-second order best fit experimental data, suggesting that the adsorption process is governed by chemical reactions and multilayer uptake. The future prospective of this work lies in the identification of alternatives to reuse Pb(II)-contaminated biomasses after heavy metal adsorption, such as material immobilization.

Preparation of Highly Crystalline Mesoporous TiO2 by Using Carbon to Protect the Pore Structure at Elevated Temperature

2010 ◽  
Vol 654-656 ◽  
pp. 2406-2409
Author(s):  
Yu Dan Zhu ◽  
Yu Lan Ding ◽  
Xiao Hua Lu ◽  
Wei Zhuang ◽  
Ling Hong Lu
Keyword(s):  
Elevated Temperature ◽  
Pore Structure ◽  
Anatase Phase ◽  
High Surface ◽  
Catalyst Support ◽  
High Surface Area ◽  
Pore Wall ◽  
Mesoporous Tio2 ◽  
Mesopore Structure ◽  
Novel Strategy

Mesoporous TiO2 with highly crystalline pore wall has an enormous potential for applications in photocatalysis, catalyst support, drug delivery, etc. However, with the sintering temperature increasing, the crystallinity of the pore wall increases while the mesopore structure tends to collapse. In this work, we presented a novel strategy for creating highly crystalline mesoporous TiO2 (MT800) by using carbon to protect the pore structure at elevated temperature. The structural characterization indicates that MT800 has highly crystalline anatase phase and processes high surface area. The photocatalysis performance was evaluated by organic degradation and the results show that MT800 has superior photocatalysis activity to the TiO2 (T800) calcined at 800°C without carbon, because of the synergies of crystallinity and mesostructure.

Synthesis and capacitive properties of carbonaceous sphere@MnO2 rattle-type hollow structures

2010 ◽  
Vol 25 (8) ◽  
pp. 1476-1484 ◽  
Author(s):  
Jintao Zhang ◽  
Jizhen Ma ◽  
Jianwen Jiang ◽  
X.S. Zhao
Keyword(s):  
Electron Microscope ◽  
Photoelectron Spectroscopy ◽  
High Surface ◽  
Hollow Spheres ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Experimental Conditions ◽  
X Ray ◽  
Hollow Structures ◽  
Capacitive Properties

Carbonaceous sphere@MnO2 rattle-type hollow spheres were synthesized under mild experimental conditions. The as-prepared hollow structures were characterized using scanning electron microscope, transmission electron microscope, x-ray diffraction, x-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and nitrogen adsorption techniques. The characterization data showed the formation of rattle-type hollow structures with a mesoporous MnO2 shell and a carbonaceous sphere core. The composition and shell thickness of the hollow spheres can be controlled experimentally. The capacitive performance of the hollow structures was evaluated by using both cycle voltammetry and charge–discharge methods. The results demonstrated a specific capacitance as high as 184 F/g at a current density of 125 mA/g. The good electrocapacitive performance resulted from the mesoporous structure and high surface area of the MnO2-based hollow spheres.

Efficient Removal of Cd2+ by the Mesoporous Silica Functionalized by APTES

2013 ◽  
Vol 726-731 ◽  
pp. 2409-2412
Author(s):  
Xiao Feng Cai ◽  
Kang Wei Ji ◽  
Wan Hao Wu ◽  
Jie Hou ◽  
Shi You Hao
Keyword(s):  
Aqueous Solution ◽  
Mesoporous Silica ◽  
Ph Value ◽  
High Surface ◽  
High Surface Area ◽  
Efficient Removal ◽  
Structure Directing Agent ◽  
Functionalized Mesoporous Silica ◽  
Adsorption Desorption ◽  
Large Pore Size

Amino-functionalized mesoporous silica (AFMS) with high amino loading, high surface area, and large pore size was synthesized using the anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as template and 3-aminopropyltriethoxysilane (APTES) as co-structure directing agent (CSDA). The synthesized AFMS was characterized by N2adsorption-desorption, TEM and elemental analyzer. The results of the removal of Cd2+from aqueous solution showed that the pH value of aqueous solution affected the removal efficiency of Cd2+greatly, and that unary adsorption isotherm of Cd2+on the AFMS was well described by the Sips isotherm model, in which the adsorption capacity was 2.43 mmol/g for Cd2+, much higher than the literature data.

Synthesis and Characterizations of MOF-199 Using PODFA as Porogen for CO2 Adsorption Applications

2016 ◽  
Vol 694 ◽  
pp. 44-49
Author(s):  
Nurfatihah Mahadi ◽  
Halina Misran ◽  
S.Z. Othman
Keyword(s):  
Fatty Alcohol ◽  
Palm Oil ◽  
Carbon Capture ◽  
Metal Organic Framework ◽  
High Surface ◽  
High Surface Area ◽  
Product Formation ◽  
Carbon Chain Length ◽  
Sem Images ◽  
Structure Directing Agent

Copper-based metal-organic framework (MOF-199, also known as Cu-BTC and HKUST-1) materials were successfully synthesized by hydrothermal method using renewable straight-chain fatty alcohol with eight carbon chain length (i.e. octyl alcohol). The addition of palm oil derived fatty alcohol (PODFA) was suggested to act as porogen (structure directing agent) that aided the particle formation and flexible porous structure. This synthesis approach was environmental-friendly and sustainable by utilizing the fatty alcohols originated from biomass such as palm oil. The resulting MOF-199 materials exhibited single crystalline octahedral morphology structure by X-ray diffraction analyses and SEM images. The optimum ratio of octyl alcohol exhibited well-defined single octahedral particles at size range of ca. 10-50 µm and reduced by-product formation of cuprous oxide at high temperature synthesis. The nature of MOF-199 having apparently high surface area, high pore volume and low density provided the possibility in carbon capture storage. The CO2 adsorption capacity of MOF-199 investigated using high pressure volumetric analyser (HPVA-II) at ambient temperature (i.e. 25 °C) was found to be at maximum working capacity.

scholarly journals Synthesis and characterization of mesoporous materials with SBA and MCM structure types

Cerâmica ◽  
2019 ◽  
Vol 65 (376) ◽  
pp. 585-591
Author(s):  
R. A. Sacramento ◽  
O. M. S. Cysneiros ◽  
B. J. B. Silva ◽  
A. O. S. Silva
Keyword(s):  
Surface Area ◽  
Mesoporous Materials ◽  
High Surface ◽  
High Surface Area ◽  
Textural Properties ◽  
N2 Adsorption ◽  
Structure Directing Agent ◽  
Type Iv ◽  
Xrd Patterns ◽  
Adsorption Desorption

Abstract Mesoporous materials are promising structures for application in catalysis and adsorption due to high surface area and large pore size. Mesoporous materials were synthesized by the hydrothermal method with novel surfactants, distinct from those observed in the literature, in order to carry out a study of its structure and to obtain materials with better textural properties. The structures synthesized with the surfactants Igepal CO630 and Brij O20 presented the best results of specific surface area, 1074 and 1075 m2.g-1, respectively. The obtained materials were characterized by XRD, TG/DTG, N2 adsorption-desorption, and FTIR techniques. XRD patterns indicated that the highly ordered mesoporous silica structures, such as MCM-41 and MCM-48, using CTMABr as the structure-directing agent and the SBA-15, SBA-16 and other SBA structures using different block copolymers were obtained. Through N2 adsorption-desorption isotherms, it was observed type IV isotherms, attributed to mesoporous materials. The FTIR spectra presented similar behaviors with characteristic vibrational bands of MCM and SBA type materials.

Extremely Effective Visible Light-Driven Generation of Hydrogen by Sol–Gel LaFeO3-Decorated g-C3N4 Photocatalyst

2020 ◽  
Vol 12 (11) ◽  
pp. 1255-1264
Author(s):  
Nada D. Al-Khthami ◽  
Mohammed Alsawat ◽  
Reda M. Mohamed ◽  
Yousef G. Alghamdi ◽  
Zaki I. Zaki
Keyword(s):  
Visible Light ◽  
Surface Area ◽  
High Surface ◽  
Sol Gel ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Basic Material ◽  
Photocatalytic Ability ◽  
Visible Light Driven ◽  
Variable Content

In order to create a new design for an efficient photocatalyst, you need to decrease the obtained band gap and isolate the charge carriers photogenerated while setting up a new visible light methodology. The latter option could be accomplished via combination of catalyst in the metal oxide form over the surface of semiconductor. Hence, the current work aimed at synthesizing a new nanocomposite material from LaFeO3/g-C3N4 through the use of mesoporous silica as a template processing g-C3N4 higher surface area, which was subsequently decorated with LaFeO3. The LaFeO3 of variable content of 1∼4% was used to decorate our targeted basic material. The structure was confirmed by ordinary techniques, in addition to photocatalytic ability via splitting water reaction. g-C3N4 and LaFeO3 photocatalytic efficiencies were compared to the newly developed LaFeO3/g-C3N4 nanocomposites showing their outstanding activity. The optimum LaFeO3 content was confirmed as 3%, which gave higher photocatalytic efficiency against both g-C3N4 and LaFeO3 (34 and 21 times respectively). To enhance the catalytic system efficiency, a scavenger with a positive hole was added as glycerol. A maximum of five runs of higher efficient reuse was examined as required, as well as stable nanocomposite photocatalyst. The mesoporous structure, high surface area, and capacity of charge separation over the photocatalysis process were all investigated as main conditions which affect photocatalytic activity of LaFeO3/g-C3N4 nanocomposites.

Iron Disulfide Cathode Material Incorporated in Highly Ordered Mesoporous Carbon for Rechargeable Lithium Ion Batteries

2020 ◽  
Vol 12 (9) ◽  
pp. 1265-1270
Author(s):  
Ying Liu ◽  
Jungwon Heo ◽  
Xueying Li ◽  
Yuanzheng Sun ◽  
Younki Lee ◽  
...  
Keyword(s):  
Mesoporous Carbon ◽  
High Surface ◽  
Active Material ◽  
High Surface Area ◽  
Lithium Ion ◽  
Mesoporous Structure ◽  
Ordered Mesoporous Carbon ◽  
Iron Disulfide ◽  
Excellent Electrochemical Performance ◽  
Ordered Mesoporous

A highly ordered mesoporous carbon@iron disulfide (CMK-5@FeS2) composite was prepared via an in-situ impregnation and sulfurization method. The CMK-5 matrix with excellent conductivity and high surface area not only formed a continuous conductive network to improve the performance of the CMK-5@FeS2 composite, but also provided sufficient space to buffer the volume changes during cycling. The CMK-5@FeS2 cell exhibited excellent electrochemical performance. After 80 cycles, the CMK-5@FeS2 cell showed the discharge capacities of 650 and 380 mAh g–1 at 2 C and 5 C, respectively. The excellent results show that CMK-5 with unique mesoporous structure can contribute to accelerating ion transfer in the electrode due to the easy accessibility of the electrolyte, which implies CMK-5@FeS2 composite could be a promising cathode active material for rechargeable lithium ion (Li-ion) batteries.

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