High Surface Area Recyclable Gold Nanoparticles Supported on n-Hydroxyapatite Catalyst via Deposition-Precipitation Technique

2014 ◽  
Vol 2 (4) ◽  
pp. 254-260
Author(s):  
S. S. Liji Sobhana ◽  
Asit Baran Mandal
Keyword(s):  
Gold Nanoparticles ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Precipitation Technique

Gold nanoparticles grown on hydrophobic and texturally-tunable PDMS-like framework

2021 ◽  
Author(s):  
Marieme Kacem ◽  
Nadia Katir ◽  
Jamal El Haskouri ◽  
Abdellatif Essoumhi ◽  
Abdelkrim El Kadib
Keyword(s):  
Gold Nanoparticles ◽  
Surface Area ◽  
Metal Clusters ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Silicas

Mesoporous silicas are among the most suitable high-surface area solids to support small-sized metal clusters and nanoparticles. Unfortunately, the instability of silica in water constitutes a serious impedement for its...

Applications of Gold Nanoparticles in Biosensors

Nano LIFE ◽  
2016 ◽  
Vol 06 (02) ◽  
pp. 1642001 ◽  
Author(s):  
Xinjun Yu ◽  
Yang Jiao ◽  
Qinyuan Chai
Keyword(s):  
Heavy Metals ◽  
Gold Nanoparticles ◽  
Optical Properties ◽  
Metal Nanoparticles ◽  
Surface Area ◽  
Surface Functionalization ◽  
High Surface ◽  
High Surface Area ◽  
Synthetic Methods ◽  
Future Perspective

Gold nanoparticles (AuNPs) as one of the most stable metal nanoparticles have demonstrated extensive applications in recent years. This paper will give a focus on the AuNPs as biosensors, due to their inertness, unique optical properties, high surface area, and various surface functionalization methods. Synthesis of AuNps and the surface functionalization will be discussed in the first part. The size, shape, and stability can be controlled by different synthetic methods, while reductant usually needed. By surface functionalization with different molecules such as polymers, nucleic acids, and proteins, AuNPs will aggregate when specified molecule linkages showing up enables selective detections. The application in biosensing to detect proteins, oligonucleotide, glucose, and heavy metals will be exemplified, followed by the summary and future perspective part in the conclusion.

Highly Uniform Self-Assembled Gold Nanoparticles over High Surface Area ZnO Nanorods as Catalysts

2014 ◽  
Vol 3 (10) ◽  
pp. M61-M64 ◽  
Author(s):  
Tarek M. Abdel-Fattah ◽  
Alex Wixtrom ◽  
Kai Zhang ◽  
Wei Cao ◽  
Helmut Baumgart
Keyword(s):  
Gold Nanoparticles ◽  
Surface Area ◽  
High Surface ◽  
Zno Nanorods ◽  
High Surface Area ◽  
Self Assembled ◽  
Highly Uniform

Gold Nanoparticles Grafted Mesoporous Silica: A Highly Efficient and Recyclable Heterogeneous Catalyst for Reduction of 4-Nitrophenol

NANO ◽  
2016 ◽  
Vol 11 (09) ◽  
pp. 1650104 ◽  
Author(s):  
Akansha Mehta ◽  
Manu Sharma ◽  
Ashish Kumar ◽  
Soumen Basu
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Mesoporous Silica ◽  
Surface Area ◽  
Heterogeneous Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Trisodium Citrate ◽  
Pure Gold ◽  
Nitrophenol Reduction

Synthesis of gold nanoparticles dispersed uniformly on mesoporous silica (mAu/SiO2) by homogeneous deposition–precipitation (HDP) method is used as an effective catalyst for reduction of 4-nitrophenol to 4-aminophenol. Silica provides support and surface area to increase the catalytic activity of gold. X-ray photon spectroscopy revealed binding energy of Au 4[Formula: see text] ([Formula: see text]84.0[Formula: see text]eV) and Au 4[Formula: see text] ([Formula: see text]87.7[Formula: see text]eV) which support the formation of Au0 on SiO2 surface. Au/SiO2 showed Langmuir type-IV isotherms which are the characteristic features of mesoporous materials furthermore, pore size decreases with incorporation of Au NP’s on SiO2 surface. The enhancement is due to the strong interaction of Au0 with silica support. The catalytic conversion was studied by UV-Visible spectroscopy and high performance liquid chromatography (HPLC) quantification method, which shows conversion of nitro group into amino group. In addition, the catalyst was easily separated and reused. The reusability of the catalyst exhibited better reduction of the 4-nitrophenol to 4-aminophenol even after 10 consecutive cycles. In comparison to trisodium citrate capped pure gold nanoparticles mAu/SiO2 catalysts showed very good catalytic activity toward nitrophenol reduction. Here we conclude that embedment of metal catalysts like Au into high surface area support like silica is a positive step toward development of novel heterogeneous catalysts.

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>

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