High Surface Area Silicon Imidonitrides: A New Class of Microporous Solid Base

1998 ◽  
Vol 10 (12) ◽  
pp. 938-942 ◽  
Author(s):  
John S. Bradley ◽  
Oliver Vollmer ◽  
Riccardo Rovai ◽  
Ullrich Specht ◽  
Frédéric Lefebvre
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Solid Base ◽  
New Class

Nanostructured TiO2 Materials: Preparation, Properties and Potential Applications (3P’s)

2017 ◽  
Vol 266 ◽  
pp. 84-89 ◽  
Author(s):  
Mohd Hasmizam Razali ◽  
Nur Arifah Ismail ◽  
Khairul Anuar Mat Amin
Keyword(s):  
Surface Area ◽  
Nanostructured Materials ◽  
Food Packaging ◽  
High Surface ◽  
High Surface Area ◽  
Bet Surface Area ◽  
X Ray Diffraction ◽  
New Class ◽  
Potential Applications ◽  
High Surface Area Materials

Nanostructured materials are a new class of materials which provide one of the greatest potentials for improving performance and extended capabilities of products in a number of applications. In particular nanostructured TiO2 was used as photocatalysts, gas sensor, solar cells and nanocomposite biomaterials. For each of these applications, aspects such as surface morphology, crystallinity and chemistry of the titania-based materials are the key parameters to be settled for the process optimization. A series of nanostructured TiO2 materials (TiO2 nanotubes, TiO2 nanorods, TiO2 nanoparticles) was synthesized using simple hydrothermal methods. X-Ray Diffraction (XRD), Field Emission Scanning Electron microscope (FESEM) and Brunauer–Emmett–Teller (BET) surface area characterization was carried out to study the properties of synthesized nanostructured TiO2 materials. The performance of synthesized nanostructured TiO2 was evaluated for various applications such as photocatalyst for methyl orange (MO) degradation and anti-bacterial thin film for biomedical and food packaging. Among the nanostructured TiO2 materials, TiO2 nanotubes shows the highest activity regardless of their applications. This is probably due to their nanotubular morphology in which provided high surface area materials. The surface area of TiO2 nanotubes was found to be 226.52 m2/g. The outer and inner diameters of nanotubes are 4 nm and 10 nm, respectively with several hundred nanometers in length. Anatase TiO2 phase structure and crystallinity of TiO2 nanotubes supports the good performances of the nanostructured materials.

Non-covalent functionalization of high-surface area nanomaterials: a new class of sorbent materials

2016 ◽  
Vol 3 (1) ◽  
pp. 138-145 ◽  
Author(s):  
Kara M. Nell ◽  
Sean A. Fontenot ◽  
Timothy G. Carter ◽  
Marvin G. Warner ◽  
Cynthia L. Warner ◽  
...  
Keyword(s):  
Trace Metal ◽  
Metal Ions ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
High Specificity ◽  
Covalent Functionalization ◽  
Trace Metal Ions ◽  
New Class ◽  
Sorbent Materials

A non-covalent approach to functionalizing nanostructured materials with high-specificity ligands yields effective sorbents for capture of trace metal ions from water.

A new class of electroactive Fe- and P-functionalized graphene for oxygen reduction

2015 ◽  
Vol 3 (20) ◽  
pp. 11031-11039 ◽  
Author(s):  
Fatemeh Razmjooei ◽  
Kiran Pal Singh ◽  
Eun Jin Bae ◽  
Jong-Sung Yu
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Functionalized Graphene ◽  
New Class ◽  
Reduced Graphene ◽  
Acidic Conditions ◽  
Orr Activity

A new class of electroactive Fe- and P-functionalized reduced graphene oxide is prepared, which illustrates high ORR activity both in alkaline and acidic conditions due to its high surface area and formation of active Fe–P complex.

Microporous Silicon Nitride-Based Solid Bases

1998 ◽  
Vol 549 ◽  
Author(s):  
J. S. Bradley ◽  
O. Vollmer ◽  
R. Rovai ◽  
F. Lefebvre
Keyword(s):  
Surface Area ◽  
Condensation Reaction ◽  
High Surface ◽  
High Surface Area ◽  
Organic Content ◽  
Gaseous Ammonia ◽  
Solid Base ◽  
Solid Base Catalysts ◽  
Base Catalysts ◽  
Knoevenagel Condensation Reaction

AbstractHigh surface area, microporous, amorphous silicon imidonitride, characterized by infrared spectroscopy, MAS 29Si NMR and surface area and porosity measurements has been prepared by the treatment of co-oligomers of methylsilazane and dimethyl silazanes with gaseous ammonia at temperatures up to 700°C. The material has a narrow pore-size distribution showing a maximum in the range associated with wide- pore zeolites (ca. 0.72 nm mean). Variation of the organic content of the silazane is a means of controlling the surface area of the resulting solid. The Knoevenagel condensation reaction of benzaldehyde with a series of active methylene compounds has been used to probe the basicity and size-selectivity of these microporous solid base catalysts.

In Situ microscopy of the anodic etching of silicon

1995 ◽  
Vol 53 ◽  
pp. 232-233
Author(s):  
Frances M. Ross ◽  
Peter C. Searson
Keyword(s):  
Composite Structures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Selective Etching ◽  
Silicon On Insulator ◽  
Second Phase ◽  
Porous Layers ◽  
New Class ◽  
Porous Semiconductors

Porous semiconductors represent a relatively new class of materials formed by the selective etching of a single or polycrystalline substrate. Although porous silicon has received considerable attention due to its novel optical properties1, porous layers can be formed in other semiconductors such as GaAs and GaP. These materials are characterised by very high surface area and by electrical, optical and chemical properties that may differ considerably from bulk. The properties depend on the pore morphology, which can be controlled by adjusting the processing conditions and the dopant concentration. A number of novel structures can be fabricated using selective etching. For example, self-supporting membranes can be made by growing pores through a wafer, films with modulated pore structure can be fabricated by varying the applied potential during growth, composite structures can be prepared by depositing a second phase into the pores and silicon-on-insulator structures can be formed by oxidising a buried porous layer. In all these applications the ability to grow nanostructures controllably is critical.

Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

2019 ◽  
Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith
Keyword(s):  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Catalyst Layer ◽  
Active Surface ◽  
Active Surface Area ◽  
High Concentration ◽  
Copper Electrodes ◽  
Surface Enhanced ◽  
Local Current

<p>This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO<sub>2</sub> electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO<sub>2</sub> electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO<sub>2</sub> electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer. </p> <p> </p>

scholarly journals Rugae-like FeP nanocrystal assembly on a carbon cloth: an exceptionally efficient and stable cathode for hydrogen evolution

Nanoscale ◽  
2015 ◽  
Vol 7 (25) ◽  
pp. 10974-10981 ◽  
Author(s):  
Xiulin Yang ◽  
Ang-Yu Lu ◽  
Yihan Zhu ◽  
Shixiong Min ◽  
Mohamed Nejib Hedhili ◽  
...  
Keyword(s):  
Gas Phase ◽  
Surface Area ◽  
Hydrogen Evolution ◽  
Hydrogen Generation ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Efficiency ◽  
Carbon Cloth ◽  
Nanocrystal Assembly

High surface area FeP nanosheets on a carbon cloth were prepared by gas phase phosphidation of electroplated FeOOH, which exhibit exceptionally high catalytic efficiency and stability for hydrogen generation.

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