scholarly journals The effect of the presence of alcohol in the dispersing phase of oxide sols on the properties of RuO2-TiO4/Ti anodes obtained by the sol-gel procedure

2000 ◽  
Vol 65 (9) ◽  
pp. 649-660 ◽  
Author(s):  
V. Panic ◽  
A. Dekanski ◽  
S. Milonjic ◽  
R. Atanasoski ◽  
B. Nikolic
Keyword(s):  
Thermal Decomposition ◽  
Cyclic Voltammetry ◽  
Electrochemical Behaviour ◽  
Sol Gel ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Accelerated Stability ◽  
Chlorine Evolution Reaction ◽  
The Stability ◽  
Chloride Salts

The effect of the addition of ethanol and 2-propanol to the dispersing phase of TiO2 and RuO2 sols mixture on the morphology and, consequently, on the electrochemical properties of the sol-gel obtained activated titanium anodes was investigated. The properties of the obtained anodes were compared to those obtained by the thermal decomposition of appropriate chloride salts. The morphology of the anode coatings was examined by scanning tunneling microscopy. The electrochemical behaviour was investigated by cyclic voltammetry and by polarization measurements. An accelerated stability test was used for the examination of the stability of the anodes under simultaneous oxygen and chlorine evolution reaction. A dependence of the anode stability on the type of added alcohol is indicated.

scholarly journals Dual role of CO in the stability of subnano Pt clusters at the Fe3O4(001) surface

2016 ◽  
Vol 113 (32) ◽  
pp. 8921-8926 ◽  
Author(s):  
Roland Bliem ◽  
Jessi E. S. van der Hoeven ◽  
Jan Hulva ◽  
Jiri Pavelec ◽  
Oscar Gamba ◽  
...  
Keyword(s):  
Density Functional ◽  
Elevated Temperatures ◽  
Time Lapse ◽  
Dual Role ◽  
Oxidation Catalyst ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Active Metal ◽  
Catalytically Active ◽  
The Stability

Interactions between catalytically active metal particles and reactant gases depend strongly on the particle size, particularly in the subnanometer regime where the addition of just one atom can induce substantial changes in stability, morphology, and reactivity. Here, time-lapse scanning tunneling microscopy (STM) and density functional theory (DFT)-based calculations are used to study how CO exposure affects the stability of Pt adatoms and subnano clusters at the Fe3O4(001) surface, a model CO oxidation catalyst. The results reveal that CO plays a dual role: first, it induces mobility among otherwise stable Pt adatoms through the formation of Pt carbonyls (Pt1–CO), leading to agglomeration into subnano clusters. Second, the presence of the CO stabilizes the smallest clusters against decay at room temperature, significantly modifying the growth kinetics. At elevated temperatures, CO desorption results in a partial redispersion and recovery of the Pt adatom phase.

scholarly journals The interface between HOPG and 1-butyl-3-methyl-imidazolium hexafluorophosphate

2016 ◽  
Vol 18 (2) ◽  
pp. 916-925 ◽  
Author(s):  
C. Müller ◽  
K. Németh ◽  
S. Vesztergom ◽  
T. Pajkossy ◽  
T. Jacob
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Scanning Tunneling Microscopy ◽  
Electrochemical Impedance ◽  
Pyrolytic Graphite ◽  
Scanning Tunneling ◽  
Highly Oriented Pyrolytic Graphite ◽  
Tunneling Microscopy

The interface between highly oriented pyrolytic graphite (HOPG) and 1-butyl-3-metyl-imidazolium hexafluorophosphate (BMIPF6) has been studied using cyclic voltammetry, electrochemical impedance spectroscopy, immersion charge measurements and in situ scanning tunneling microscopy (in situ STM).

scholarly journals On the stability of platinum-composite electrocatalysts prepared with different substrate materials

2016 ◽  
Vol 6 (1) ◽  
pp. 29
Author(s):  
Milica G. Košević ◽  
Gavrilo M. Šekularac ◽  
Vladimir V. Panić
Keyword(s):  
Cyclic Voltammetry ◽  
Steady State ◽  
Sol Gel ◽  
Colloidal Dispersion ◽  
Sweep Rate ◽  
Initial Activity ◽  
Microwave Assisted ◽  
Commercial Carbon ◽  
The Stability ◽  
Cv Measurements

<p><span lang="EN-US">Cyclic voltammetry (CV) measurements were conducted and analyzed for a preliminary estimation of the stability of composite electrocatalysts based on Pt. The changes in CV currents of platinum nanoparticles supported on TiO<sub>2</sub> were compared to the changes of those supported on commercial carbon. TiO<sub>2</sub> was synthesized by sol-gel method and Pt was deposited from Pt colloidal dispersion synthesized by microwave-assisted polyol process. It was found that Pt component in both Pt/TiO<sub>2</sub> and Pt/C behaves similarly with respect to stability and activity during the cycling. The loss in activity with cycling was linear and strongly depended on sweep rate, i.e., the relative loss is higher at lower sweep rates. The steady state activities for both electrocatalysts were reached at the level of 65 % of initial activity and required more than 100 voltammetric cycles.</span></p>

On The Stability of Triangular Janus MoSSe Quantum-Dots: Shape and Size Effects

2021 ◽  
Author(s):  
J. I. Paez-Ornelas ◽  
R. Ponce-Perez ◽  
H. N. Fernández-Escamilla ◽  
D. M. Hoat ◽  
E. A. Murillo-Bracamontes ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Scanning Tunneling ◽  
Transition Metal Dichalcogenide ◽  
Tunneling Microscopy ◽  
Shape Stability ◽  
Catalytic Material ◽  
Catalytic Sites ◽  
Density Concentration ◽  
The Stability ◽  
Reaction Processes

Abstract Asymmetric Janus transition metal dichalcogenide MoSSe is a promising catalytic material due to the intrinsic in-plane dipole of its opposite faces. The atomic description of the structures observed by experimental techniques is relevant to tune and optimize the reaction processes on its surfaces. Furthermore, the experimentally observed triangular morphologies in MoSSe suggest that an analysis of the chemical environment of its edges is vital to understand its reactivity. Here we analyze the size-shape stability among different triangular structures-quantum dots-proposed from the ideal S(-1010) and Mo(10-10) terminations. Our stability analysis evidenced that the S-Se termination is more stable than Mo; moreover, as the size of the quantum dot increases, its stability increases as well. Besides, a trend is observed, with the appearance of elongated Mo-S/Se bonds at symmetric positions of the edges. Tersoff-Hamann scanning tunneling microscopy images for both faces of the stablest models are presented. Electrostatic potential isosurfaces denote that the basal plane on the S face of both configurations remains the region with more electron density concentration. These results point toward the differentiated activity over both faces. Finally, our study denotes the exact atomic arrangement on the edges of MoSSe quantum dots corresponding with the formation of S/Se dimmers who decorates the edges and their role along with the faces as catalytic sites.

Scanning Probe Microscopy with Diamond Tip in Tribo-nanolithography

2011 ◽  
Vol 1318 ◽  
Author(s):  
Oleg Lysenko ◽  
Vladimir Grushko ◽  
Evgeni Mitskevich ◽  
Athanasios Mamalis
Keyword(s):  
Scanning Probe Microscopy ◽  
Experimental Studies ◽  
Scanning Probe ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Boron Doped Diamond ◽  
High Stiffness ◽  
Boron Doped ◽  
Afm Cantilever ◽  
The Stability

ABSTRACTThe results obtained by direct nano-patterning demonstrate the potential of the SPM-based techniques that include surface scratching to create 3D nanostructures. Such techniques became known as tribo-nanolithography and have prospects of being successfully implemented in the future nanofabrication industry. An important obstacle to this, however, is the effect of wear at the nanometer scale which is critical to the stability of tribo-nanolithoraphic processes. Such stability is achievable via in-depth theoretical and experimental studies of friction at the nanoscale along with the development of pioneering equipment. Our work presents the results of experimental fabrication of nanostructures formed by nanoscratching with the use of the multifunctional scanning tunneling microscopy previously developed by the authors. The authors attempted scratching the silicon surface by using a boron-doped diamond tip. This operation was undertaken in the same direction sequentially with the tip sliding a side of the groove by one of the tip’s facets and the consequent surface scanning. Although not being applicable to non-conductive surfaces, the proposed technique has significant advantages. One advantage is related to the high stiffness of the tunneling probe as compared to the stiffness of the AFM cantilever. High stiffness and perpendicularity of the tip to the surface during surface processing eliminates bending beam effects on the typical AFM and ensures machining effectiveness. Purposely synthesized boron-doped single-crystal diamonds were used as a tip material. The results of experimental fabrication of nanostructures formed by nanoscratching with the use of the multifunctional scanning probe are demonstrated and discussed.

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