Control of growth solution on the dimensions of gold nanorods accounted for LSPR sensitivity toward liquid ammonia sensing

Author(s):  
Saroj Bala ◽  
Sumit Dokwal ◽  
Sangeeta Saini ◽  
Suman Mahendia ◽  
Shyam Kumar
2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Christopher J. Ward ◽  
Robert Tronndorf ◽  
Alicia S. Eustes ◽  
Maria L. Auad ◽  
Edward W. Davis

The effects of the seed reaction conditions on the two-step seed-mediated growth of gold nanorods and the effect of gold and reducing agent content in the growth solution were evaluated. Results indicate that the reaction conditions used to produce the seeds have a significant impact on the aspect ratio of the gold nanorods produced. Increasing the concentration of gold or the reaction temperature in the seed production step results in lower length to diameter (aspect ratio) gold rods. In addition, the amount of prepared seed added to the growth solution impacts the rod aspect ratio, with increasing amounts of seed reducing the aspect ratio. The effects of reducing agent, ascorbic acid (AA), and gold content of the growth solution on the aspect ratio of the produced rods are strongly interrelated. There exists a minimum ascorbic acid to gold concentration below which rods will not form; however, increasing the ratio above this minimum results in shorter rods being formed. Characterization of nanorod growth is performed by UV-vis-NIR spectrophotometry and transmission electron microscopy (TEM).


2006 ◽  
Vol 921 ◽  
Author(s):  
Ru-Shi Liu ◽  
H. M. Chen ◽  
S. F. Hu

AbstractA new approach to fabricate long length of gold nanorods by controlling the volume of growth solution will be reported. The shape evolutions ranging from fusiform nanoparticles to 1-D rods was observed. Increasing the addition of growth solution can control the length of nanorods. The length of rods can be extended to 2 £gm, and nanorods with aspect ratios of up to ~ 70 could be obtained. Moreover, X-ray absorption spectroscopy (XAS) is applied herein to elucidate the growth mechanism of gold nanorods. The gold ions were directly reduced to gold atoms by ascorbic acid during the reaction, and then gold atoms were deposited on the surface of gold seeds that were introduced into the reaction. Extended X-ray absorption fine structure (EXAFS) confirmed the growth of gold and the environment around Au atoms over the reaction. The XAS are expected to have wide applications in the growth of gold and other related materials.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Jong-Yeob Kim ◽  
Chil Seong Ah ◽  
Du-Jeon Jang

Aspect ratios of gold nanorods have been finely modified in reduction-limited conditions via two electrochemical ways: by changing the amount of a growth solution containing small gold clusters in the presence of already prepared gold nanorods as seeds or by changing electrolysis time in the presence or absence of a silver plate. While the atomic molar ratio of gold in the growth solution to gold in the seed solution is critical in the former method, the relative molar ratio of gold ions to silver ions in the electrolytic solution is important in the latter way for the control of the aspect ratios of gold nanorods. The aspect ratios of gold nanorods decrease with an increase of electrolysis time in the absence of a silver plate, but they increase with an increase of electrolysis time in the presence of a silver plate.


1976 ◽  
Vol 73 ◽  
pp. 849-851 ◽  
Author(s):  
Thomas Kottarathil ◽  
Gérard Lepoutre

2017 ◽  
Vol 62 (1-2) ◽  
pp. 23-31
Author(s):  
L.C. Şuşu ◽  
◽  
A.M. Crăciun ◽  
S. Aştilean ◽  
◽  
...  

2009 ◽  
Vol 36 (11) ◽  
pp. 1402-1407 ◽  
Author(s):  
Mei LIU ◽  
Pei-Hui YANG ◽  
Ji-Ye CAI

Author(s):  
Priya Gupta ◽  
Savita Maurya ◽  
Narendra Kumar Pandey ◽  
Vernica Verma

: This review paper encompasses a study of metal-oxide and their composite based gas sensors used for the detection of ammonia (NH3) gas. Metal-oxide has come into view as an encouraging choice in the gas sensor industry. This review paper focuses on the ammonia sensing principle of the metal oxides. It also includes various approaches adopted for increasing the gas sensitivity of metal-oxide sensors. Increasing the sensitivity of the ammonia gas sensor includes size effects and doping by metal or other metal oxides which will change the microstructure and morphology of the metal oxides. Different parameters that affect the performances like sensitivity, stability, and selectivity of gas sensors are discussed in this paper. Performances of the most operated metal oxides with strengths and limitations in ammonia gas sensing application are reviewed. The challenges for the development of high sensitive and selective ammonia gas sensor are also discussed.


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