Single-Molecule Nanocatalysis Reveals Catalytic Activation Energy of Single Nanocatalysts

2016 ◽  
Vol 138 (38) ◽  
pp. 12414-12421 ◽  
Author(s):  
Tao Chen ◽  
Yuwei Zhang ◽  
Weilin Xu
2008 ◽  
Vol 113 (6) ◽  
pp. 2078-2081 ◽  
Author(s):  
Andrei Honciuc ◽  
Alexander L. Howard ◽  
Daniel K. Schwartz

1999 ◽  
Vol 581 ◽  
Author(s):  
U. Simon

ABSTRACTBy means of integral temperature dependent conductance measurements, the effective capacitance of ligand stabilized nanoparticles, arranged in dense packings or networks, can be deduced from the activation energy of the charge transport, for which the use of the Landauer formula is proposed. According to this, the barrier resistance in ligand stabilized nanoparticle arrangements depends predominantly on the inter particle spacing rather than on the chemical composition of the molecules. Comparison with data of the single molecule resistance determined by local probe techniques or by theoretical methods shows remarkable aggreement.


Langmuir ◽  
2009 ◽  
Vol 25 (13) ◽  
pp. 7389-7392 ◽  
Author(s):  
Andrei Honciuc ◽  
Denver Jn. Baptiste ◽  
Ian P. Campbell ◽  
Daniel K. Schwartz

Author(s):  
George C. Ruben

Single molecule resolution in electron beam sensitive, uncoated, noncrystalline materials has been impossible except in thin Pt-C replicas ≤ 150Å) which are resistant to the electron beam destruction. Previously the granularity of metal film replicas limited their resolution to ≥ 20Å. This paper demonstrates that Pt-C film granularity and resolution are a function of the method of replication and other controllable factors. Low angle 20° rotary , 45° unidirectional and vertical 9.7±1 Å Pt-C films deposited on mica under the same conditions were compared in Fig. 1. Vertical replication had a 5A granularity (Fig. 1c), the highest resolution (table), and coated the whole surface. 45° replication had a 9Å granulartiy (Fig. 1b), a slightly poorer resolution (table) and did not coat the whole surface. 20° rotary replication was unsuitable for high resolution imaging with 20-25Å granularity (Fig. 1a) and resolution 2-3 times poorer (table). Resolution is defined here as the greatest distance for which the metal coat on two opposing faces just grow together, that is, two times the apparent film thickness on a single vertical surface.


Author(s):  
George C. Ruben ◽  
William Krakow

Tobacco primary cell wall and normal bacterial Acetobacter xylinum cellulose formation produced a 36.8±3Å triple-stranded left-hand helical microfibril in freeze-dried Pt-C replicas and in negatively stained preparations for TEM. As three submicrofibril strands exit the wall of Axylinum , they twist together to form a left-hand helical microfibril. This process is driven by the left-hand helical structure of the submicrofibril and by cellulose synthesis. That is, as the submicrofibril is elongating at the wall, it is also being left-hand twisted and twisted together with two other submicrofibrils. The submicrofibril appears to have the dimensions of a nine (l-4)-ß-D-glucan parallel chain crystalline unit whose long, 23Å, and short, 19Å, diagonals form major and minor left-handed axial surface ridges every 36Å.The computer generated optical diffraction of this model and its corresponding image have been compared. The submicrofibril model was used to construct a microfibril model. This model and corresponding microfibril images have also been optically diffracted and comparedIn this paper we compare two less complex microfibril models. The first model (Fig. 1a) is constructed with cylindrical submicrofibrils. The second model (Fig. 2a) is also constructed with three submicrofibrils but with a single 23 Å diagonal, projecting from a rounded cross section and left-hand helically twisted, with a 36Å repeat, similar to the original model (45°±10° crossover angle). The submicrofibrils cross the microfibril axis at roughly a 45°±10° angle, the same crossover angle observed in microflbril TEM images. These models were constructed so that the maximum diameter of the submicrofibrils was 23Å and the overall microfibril diameters were similar to Pt-C coated image diameters of ∼50Å and not the actual diameter of 36.5Å. The methods for computing optical diffraction patterns have been published before.


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