EDTA-Directed Synthesis of Highly Active Porous Titania with Bicrystalline Framework

2007 ◽  
Vol 7 (12) ◽  
pp. 4339-4345 ◽  
Author(s):  
Yun Liu ◽  
Chun-Yan Liu ◽  
Zhi-Ying Zhang
Keyword(s):  
Organic Molecules ◽  
High Surface ◽  
Hydrothermal Process ◽  
High Surface Area ◽  
Porous Structures ◽  
Sodium Salts ◽  
Highly Active ◽  
Porous Titania ◽  
Directed Synthesis ◽  
Facile Hydrothermal Process

Porous titania with bicrystalline (anatase and rutile) framework was successfully synthesized by a facile hydrothermal process using inexpensive and nontoxic organic molecules, EDTA (ethylenediamine-tetra-acetic acid) or its sodium salts as a template, which could be removed from porous titania by the extraction with sodium hydroxide aqueous solution and then easily recovered by acidification. XRD investigation suggested that the ratio of anatase to rutile could be readily tuned by employing different sodium salts of EDTA. All of as-prepared porous titania showed higher activities than the commercial photocatalyst P25 for the degradation of methyl orange (MO), because of the high surface area, bicrystalline phase composition and bimodal porous structures.

Efficiency Enhancement in Dye-Sensitized Solar Cell Using TiO2 /Ilmenite-Derived Nanofiber Composite as Working Electrode

2014 ◽  
Vol 925 ◽  
pp. 600-604
Author(s):  
Athapon Simpraditpan ◽  
Thanakorn Wirunmongkol ◽  
Sorapong Pavasupree ◽  
Wisanu Pecharapa
Keyword(s):  
Nanocomposite Film ◽  
High Surface ◽  
Hydrothermal Process ◽  
High Surface Area ◽  
Dye Sensitized Solar Cells ◽  
Nanocomposite Films ◽  
Film Electrode ◽  
Photoelectric Conversion ◽  
Dye Sensitized ◽  
Working Electrode

TiO2 nanocomposite films of calcined TiO2 nanofibers and commercial-grade TiO2 nanoparticles Degussa (P25) utilized as working electrode of dye-sensitized solar cells (DSSCs) are prepared by a doctor blade method. TiO2 nanofibers were synthesized from ilmenite mineral by hydrothermal process in combination with calcinations process. The prepared samples are characterized by XRD, XPS and TEM. The photoelectric conversion performance of the DSSC based on nanocomposite film electrode was compared to the device fabricated by pure P25 at the same film thickness. The result shows that as calcination temperature increases, the transformation of nanofibers to nanorods and nanoparticles were observed. The energy conversion efficiency (ƞ) of the device tends to with increasing calcined temperature. The greatest ƞ is 3.90% obtained from DSSC fabricated from nanocomposite film electrode of 5 wt.% nanofibers calcined at 800 oC for 2 h mixed with P25, indicating the significant enhancement in its performance by the incorporation of the nanofibers. This enhancement of DSSCs may correlate to high surface area, higher light scattering and light harvesting, low charge recombination and fast electron-transfer rate by nanofibers.

Highly active mixed-valent MnOxspheres constructed by nanocrystals as efficient catalysts for long-cycle Li–O2batteries

2016 ◽  
Vol 4 (43) ◽  
pp. 17129-17137 ◽  
Author(s):  
Sanpei Zhang ◽  
Zhaoyin Wen ◽  
Yang Lu ◽  
Xiangwei Wu ◽  
Jianhua Yang
Keyword(s):  
Surface Area ◽  
Low Cost ◽  
High Surface ◽  
High Surface Area ◽  
Long Cycle ◽  
Highly Active

We demonstrate a low-cost and facile strategy to synthesize mixed-valent MnOxspheres constructed from nanocrystals (~5 nm), containing MnII, MnIII, and MnIVspecies. Such highly active mixed-valent MnOxspheres with high surface area greatly improve the performance of Li–O2batteries.

scholarly journals Ultrasonic-assisted preparation of highly active Co3O4/MCM-41 adsorbent and its desulfurization performance for low H2S concentration gas

RSC Advances ◽  
2020 ◽  
Vol 10 (50) ◽  
pp. 30214-30222
Author(s):  
Bolong Jiang ◽  
Jiaojing Zhang ◽  
Yanguang Chen ◽  
Hua Song ◽  
Tianzhen Hao ◽  
...  
Keyword(s):  
Surface Area ◽  
Active Sites ◽  
High Surface ◽  
High Surface Area ◽  
Highly Active ◽  
Ultrasonic Assisted ◽  
Sulfur Capacity ◽  
Mcm 41

Co3O4/MCM-41 adsorbent with high surface area and more active sites was successfully prepared by ultrasonic assisted impregnation (UAI) technology and it has been found that the sulfur capacity was improved by 33.2% because of ultrasonication.

scholarly journals Structural Flexibility in Activated Carbon Materials Prepared under Harsh Activation Conditions

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1988 ◽  
Author(s):  
Fabiano Gomes Ferreira de Paula ◽  
Ignacio Campello-Gómez ◽  
Paulo Fernando Ribeiro Ortega ◽  
Francisco Rodríguez-Reinoso ◽  
Manuel Martínez-Escandell ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Structural Changes ◽  
Organic Molecules ◽  
Carbon Materials ◽  
High Surface ◽  
High Surface Area ◽  
Koh Activation ◽  
3D Network ◽  
Activation Conditions

Although traditionally high-surface area carbon materials have been considered as rigid structures with a disordered three dimensional (3D) network of graphite microdomains associated with a limited electrical conductivity (highly depending on the porous structure and surface chemistry), here we show for the first time that this is not the case for activated carbon materials prepared using harsh activation conditions (e.g., KOH activation). In these specific samples a clear structural re-orientation can be observed upon adsorption of different organic molecules, the structural changes giving rise to important changes in the electrical resistivity of the material. Whereas short chain hydrocarbons and their derivatives give rise to an increased resistivity, the contrary occurs for longer-chain hydrocarbons and/or alcohols. The high sensitivity of these high-surface area carbon materials towards these organic molecules opens the gate towards their application for sensing devices.

Transport in Stochastic Fibrous Networks

2000 ◽  
Vol 123 (1) ◽  
pp. 12-19 ◽  
Author(s):  
X. Cheng ◽  
A. M. Sastry ◽  
B. E. Layton
Keyword(s):  
Volume Fraction ◽  
High Surface ◽  
High Surface Area ◽  
Statistical Technique ◽  
Porous Structures ◽  
Fibrous Materials ◽  
Aspect Ratios ◽  
And Performance ◽  
2D Network ◽  
Key Questions

Some fundamental issues concerning the design and performance of stochastic porous structures are examined, stemming from application of advanced fibrous electrode substrates in NiMH automotive cells. These electrodes must resist corrosion and local failures under hundreds of charge/discharge cycles. Such fibrous materials can be effectively used as substrates for chemical reactions because of their combinations of high surface area and high conductivity. Key questions concerning the relationships among connectivity and conductivity, scale and variability in material response are addressed. Two techniques are developed and compared for use in predicting these materials’ conductivity. The first approach uses a statistical technique in conjunction with an adaptation of classic micromechanical models. The second approach uses the statistical generation technique, followed by an exact calculation of 2D network conductivity. The two techniques are compared with one another and with classic results. Several important conclusions about the design of these materials are presented, including the importance of use of fibers with aspect ratios greater than at least 50, the weak effect of moderate alignment for unidirectional conductivity, and the weak power-law behavior of conductivity versus volume fraction over the range of possible behaviors.

Preparation of Mesoporous TiO2 Microspheres by Ultrasonic-Hydrothermal Process and its Photocatalysis

2012 ◽  
Vol 578 ◽  
pp. 99-104
Author(s):  
Yang Lin Liu ◽  
Xue Chen Duan ◽  
Shu Yun Liu ◽  
Yan Yan Liu
Keyword(s):  
Photocatalytic Activity ◽  
Crystal Size ◽  
High Surface ◽  
Hydrothermal Process ◽  
High Surface Area ◽  
Heat Treating ◽  
Mesoporous Tio2 ◽  
Average Crystal Size ◽  
Tio2 Microspheres ◽  
Effects Of Temperature

Mesoporous TiO2 microspheres were prepared by Ultrasonic-Hydrothermal Process with tetrabutyltitanate as titanium resource and octadecylamine as template. The effects of temperature and time of hytrothermol process, and calcination temperature on the structure had been investigated via XRD,SEM,TEM.The results indicated it will be better hythrothermol treating 20h at 120°Cand then heat-treating 4h at 400°C. A high surface area of 261.7 m2/g and pore volume of 0.28cm3/g was obtained in the corresponding sample with quite narrow distribution,and centering at 4.3nm in diameter.TiO2 frame was highly crystallized, showed the characteristic of pure anataste, with average crystal size of 10.0nm. The as-prepared sample possess a morphology of microspheres with diameter about 100-300nm.The photocatalytic activity was valuated by photodegradation of methly orange. The resultes indicated 99.79% of methly orange in the solution was removed after 30min photocatalytic treatment.

Ordered mesoporous silica cubic particles decorated with silver nanoparticles: a highly active and recyclable heterogeneous catalyst for the reduction of 4-nitrophenol

2019 ◽  
Vol 48 (8) ◽  
pp. 2692-2700 ◽  
Author(s):  
Hui-Tao Fan ◽  
Xue-Guo Liu ◽  
Xiao-Jing Xing ◽  
Bo Li ◽  
Kun Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Catalytic Activity ◽  
Mesoporous Silica ◽  
Potential Application ◽  
High Surface ◽  
High Surface Area ◽  
Ordered Mesoporous Silica ◽  
Highly Active ◽  
Ordered Mesoporous ◽  
Recyclable Heterogeneous Catalyst

An Ag–OMS-C nanocomposite with a high surface area was proposed, and its potential application for catalytic activity was highlighted.

scholarly journals Comparison of physicochemical properties and selective catalytic reduction activities of CeMn/TiO2 catalysts with and without phosphorus additives

2021 ◽  
Author(s):  
Zeycan KESKİN
Keyword(s):  
Selective Catalytic Reduction ◽  
Catalytic Reduction ◽  
Catalyst Activity ◽  
High Surface ◽  
High Surface Area ◽  
Phosphorus Loading ◽  
X Ray Diffraction ◽  
Reduction Activity ◽  
Highly Active ◽  
Loading Amount

Abstract Lubricant additives contain phosphorus, which has a fly ash effect. Phosphorus negatively affects catalyst activity. Determining the effects of phosphorus loading amount on the catalytic activity is important for the development of catalysts with high NOx reduction. This study focuses on the control of NOx emissions, one of the air pollutants released from the diesel engine. The catalysts used in the reduction of NOx emissions were synthesized by washcoating method. Ce and Mn contents of all catalysts were adjusted as 3%, while the phosphorus contents of poisoned catalysts were adjusted as 0.5% and 1%. For this purpose, cordierite with high surface area was used. The catalysts were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Brunauer-Emmett-Teller (BET), X-Ray diffraction (XRD) and ultraviolet visible spectroscopy (UV-Vis) analyzes. The NOx reduction activity of with and without phosphorus doped CeMn/TiO2 catalysts was investigated with the designed selective catalytic reduction system (SCR). NOx conversion ratios of the CeMn/TiO2 catalyst reached the high values of 84.6% at 280°C. After the phosphorus loading, the structure of the CeMn/TiO2 catalyst deteriorated, and the NOx conversion ratios decreased. 0.5P-CeMn/TiO2 and 1P-CeMn/TiO2 catalysts showed lower NOx conversion ratios compared to CeMn/TiO2 catalyst. CeMn-TiO2 catalyst was found highly active for SCR at all tests. Phosphorus loading caused deactivation of the catalyst and deactivation increased due to the increase in phosphorus loading amount.

Highly Active TiO2-MoS2 Composite for Visible Light Photocatalytic Applications

2015 ◽  
Vol 830-831 ◽  
pp. 553-556 ◽  
Author(s):  
S.M.Y. Mohamed Mukthar Ali ◽  
K.Y. Sandhya
Keyword(s):  
Visible Light ◽  
High Surface ◽  
High Surface Area ◽  
Titanium Isopropoxide ◽  
Solvent Mixture ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Highly Active ◽  
Visible Light Active ◽  
Light Absorbance

Efficient visible light active TiO2-Molybdenum sulphide (TiO2-MoS2) composites were prepared by solvothermal methodfrom titanium isopropoxide and commercial MoS2 using N-methyl 2-pyrrolidone (NMP) and isopropanol (IPA) solvent mixture. Extended absorption band edge and enhanced visible light absorbance are supplemented intothe TiO2-MoS2 composites by this method. While TiO2 shows ~48% visible light photodegradation of rhodamine B (RhB) the TiO2-MoS2(0.24) exhibits~74% of degradation. In addition to the visible light enhancement, very high surface area and reduced charge transfer resistance at the interfaces are attributed to the enhanced activity of the composite.

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