High surface area submicrometer-sized β-SiC particles grown by shape memory synthesis method

2005 ◽  
Vol 14 (8) ◽  
pp. 1353-1360 ◽  
Author(s):  
Nicolas Keller ◽  
Olivier Reiff ◽  
Valérie Keller ◽  
Marc J. Ledoux
2016 ◽  
Vol 45 (15) ◽  
pp. 6329-6333 ◽  
Author(s):  
Gholamhossein Mohammadnezhad ◽  
Oluseun Akintola ◽  
Winfried Plass ◽  
Frank Steiniger ◽  
Martin Westermann

Nano boehmite with unprecedented high surface area and pore volume (802 m2 g−1, 2.35 cm3 g−1) was prepared using a facile, green and efficient surfactant-free synthesis method.


2017 ◽  
Vol 5 (22) ◽  
pp. 10957-10967 ◽  
Author(s):  
Dennis Zywitzki ◽  
Hangkun Jing ◽  
Harun Tüysüz ◽  
Candace K. Chan

A facile approach for the preparation of high surface area, Ti3+ containing titania with good activity for photocatalytic H2 production is reported.


2011 ◽  
Vol 691 ◽  
pp. 92-98 ◽  
Author(s):  
R. Carrera ◽  
A.L. Vázquez ◽  
S. Castillo ◽  
E.M. Arce Estrada

Nowadays, nanostructured semiconductor materials offer promising opportunities for a new generation of materials such as TiO2nanoparticles with improved properties for their application in the environmental catalysis field. It is well known that the phocatalytic activity of the TiO2nanoparticles is strongly dependent on the surface area, crystal size, phase composition and synthesis method. Thus, the preparation conditions clearly affect the photocatalytic activity of the TiO2nanoparticles. This work deals with the study of the structure of TiO2nanoparticles that were synthesized by the sol-gel method (using isopropanol as solvent), and calcined at 200 and 500°C. The obtained samples were characterized by the XRD-Rietveld refinement, BET and TEM techniques; and tested in the photodecomposition of acetaldehyde. The evaluations were carried out at room temperature by using CH3CHO (300 ppmv), O2(2.0 %) in helium balance in a quartz glass photoreactor (gas phase) with a 365-UV light lamp. According to the results, the sample that presented the highest activity in the photocatalytic oxidation of acetaldehyde (96.4%) was the one annealed at 200 °C. This sample showed the following proportion of phases: anatase (62.88%) with a tetragonal structure (a=0.3790926, b=0.3790926, c=0.9495732) nm; and b) brookite (37.12%) with an orthorhombic structure (a=0.9167624, b=0.5416461, c=0.5210546) nm. The surface area was 189 m2/g and the average crystal size was 7.03 nm. From the results, it can be seen that this material showed high activity in the photocatalytic degradation of acetaldehyde because of: the presence of a mixture of the anatase (higher proportion) and brookite phases, nanometric crystal size and high surface area obtained in this TiO2material. According to the aforementioned, this material can be considered as a good option for the decomposition of acetaldehyde and other volatile organic compounds (VOCs) in confined spaces.


1992 ◽  
Vol 7 (10) ◽  
pp. 2840-2845 ◽  
Author(s):  
Donald D. Beck ◽  
Richard W. Siegel

A variety of TiO2 materials, including a nanophase TiO2 powder, were evaluated for their ability to dissociatively adsorb H2S in a H2 environment. A temperature programmed desorption technique was used to determine the rate of sulfide accumulation on the surface of the samples as a measurement of initial activity. The initial activity for the gas condensation-produced nanophase TiO2 with its rutile structure was found to be greater than that for other samples of TiO2 tested. When normalized for surface area, the initial specific activities of the rutile samples studied for the dissociative adsorption of H2S were similar in magnitude, but significantly higher than those of the anatase TiO2 samples investigated. Thus, the improvement in the activity is attributed mainly to the ability of the nanophase synthesis method to produce high surface area rutile TiO2. When evaluated using x-ray photoelectron spectroscopy, the nanophase TiO2 was found to be significantly deficient in oxygen. Annealing this material in oxygen decreased the number of anion vacancies and lowered the activity. Thus, we conclude that oxygen vacancies also contribute to the H2S dissociative adsorption activity.


2017 ◽  
Vol 5 (27) ◽  
pp. 14444-14444
Author(s):  
Dennis Zywitzki ◽  
Hangkun Jing ◽  
Harun Tüysüz ◽  
Candace K. Chan

Correction for ‘High surface area, amorphous titania with reactive Ti3+ through a photo-assisted synthesis method for photocatalytic H2 generation’ by Dennis Zywitzki et al., J. Mater. Chem. A, 2017, 5, 10957–10967.


2020 ◽  
Vol 22 (34) ◽  
pp. 18868-18881
Author(s):  
Anita Hamar Reksten ◽  
Andrea E. Russell ◽  
Peter W. Richardson ◽  
Stephen J. Thompson ◽  
Karina Mathisen ◽  
...  

In situ XAS measurements show that iridium oxide electrocatalysts manufactured by the polymeric precursor synthesis method contain a significant fraction of elemental iridium metal and that potential cycling only oxidises a thin layer of the elemental component of the composite.


Author(s):  
Kailun Yang ◽  
Recep Kas ◽  
Wilson A. Smith

<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>


Nanoscale ◽  
2015 ◽  
Vol 7 (25) ◽  
pp. 10974-10981 ◽  
Author(s):  
Xiulin Yang ◽  
Ang-Yu Lu ◽  
Yihan Zhu ◽  
Shixiong Min ◽  
Mohamed Nejib Hedhili ◽  
...  

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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