Preparation and Characterization of Single-Atom Tips

Nano Letters ◽  
2004 ◽  
Vol 4 (12) ◽  
pp. 2379-2382 ◽  
Author(s):  
Hong-Shi Kuo ◽  
Ing-Shouh Hwang ◽  
Tsu-Yi Fu ◽  
Jun-Yi Wu ◽  
Che-Cheng Chang ◽  
...  
Keyword(s):  
Single Atom

Identifying the Types and Characterization of the Active Sites on M−X−C Single‐Atom Catalysts

ChemPhysChem ◽  
2020 ◽  
Vol 21 (23) ◽  
pp. 2486-2496
Author(s):  
Jiarui Yang ◽  
Dingsheng Wang ◽  
Yadong Li
Keyword(s):  
Active Sites ◽  
Single Atom

Synthesis and characterization of μ-nitrido, μ-carbido and μ-oxo dimers of iron octapropylporphyrazine

2015 ◽  
Vol 44 (5) ◽  
pp. 2240-2251 ◽  
Author(s):  
Cédric Colomban ◽  
Evgeny V. Kudrik ◽  
Dmitry V. Tyurin ◽  
Florian Albrieux ◽  
Sergei E. Nefedov ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Macrocyclic Complexes ◽  
Single Atom ◽  
Synthesis And Characterization ◽  
Structural And Electronic Properties

The structural and electronic properties of single-atom bridged diiron macrocyclic complexes are determined by the nature of the bridge.

Characterization of single-atom catalysts by EELS and EDX spectroscopy

2018 ◽  
Vol 193 ◽  
pp. 111-117 ◽  
Author(s):  
R.F. Egerton ◽  
M. Watanabe
Keyword(s):  
Single Atom

scholarly journals Enhanced Stability of Pt-Cu Single-Atom Alloy Catalysts: In Situ Characterization of the Pt/Cu(111) Surface in an Ambient Pressure of CO

2018 ◽  
Vol 122 (8) ◽  
pp. 4488-4495 ◽  
Author(s):  
Juan Pablo Simonovis ◽  
Adrian Hunt ◽  
Robert M. Palomino ◽  
Sanjaya D. Senanayake ◽  
Iradwikanari Waluyo
Keyword(s):  
Ambient Pressure ◽  
Single Atom ◽  
In Situ Characterization ◽  
Alloy Catalysts ◽  
Enhanced Stability ◽  
Single Atom Alloy

scholarly journals Ligand-Metal Charge Transfer Induced via Adjustment of Textural Properties Controls the Performance of Single-Atom Catalysts During Photocatalytic Degradation

2021 ◽  
Author(s):  
Jiaxu Liu ◽  
Yajun Zou ◽  
Daniel Cruz ◽  
Aleksandr Savateev ◽  
Markus Antonietti ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Heterogeneous Catalysts ◽  
Photophysical Properties ◽  
Organic Pollutant ◽  
Textural Properties ◽  
Single Atom ◽  
Single Atoms ◽  
Ligand Charge Transfer ◽  
Kinetic Investigations

Because of their peculiar nitrogen-rich structure, carbon nitrides are convenient polydentate ligands for designing single-atom-dispersed photocatalysts. However, the relation of catalysts textural properties with their photophysical properties and as a result activity in photocatalytic applications is rarely elaborated. Herein we report the preparation and characterization of a series of single-atom heterogeneous catalysts featuring highly-dispersed Ag and Cu species on mesoporous graphitic C<sub>3</sub>N<sub>4</sub>. We show that adjustment of materials textural properties and thereby metal single atoms coordination mode enables ligand-to-metal (LMCT) or ligand-to-metal-to-ligand charge transfer (LMLCT), a property tha was long speculated in single-atom catalysis but never observed. We employ the developed materials in the degradation of organic pollutant under irradiation with visible light. Kinetic investigations under flow conditions show that single atoms of Ag and Cu decrease the amount of toxic organic fragmentation products, while leading to a higher selectivity towards full calcination. The results correlate with the selected mode of charge transfer in the designed photocatalysts and provide a new understanding of the surface state of single-atom catalysts. The concepts can be exploited further to rationally design and optimize other single-atom materials.

scholarly journals In Situ/Operando Techniques for Characterization of Single-Atom Catalysts

ACS Catalysis ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 2521-2531 ◽  
Author(s):  
Xuning Li ◽  
Xiaofeng Yang ◽  
Junming Zhang ◽  
Yanqiang Huang ◽  
Bin Liu
Keyword(s):  
Single Atom

Simulations of Surface Defects Characterization Using Force Modulation Atomic Force Microscopy

2009 ◽  
Author(s):  
Hossein Nejat Pishkenari ◽  
Ali Meghdari
Keyword(s):  
Surface Defects ◽  
Interatomic Potential ◽  
Single Atom ◽  
Force Microscopy ◽  
Force Modulation ◽  
Atomic Force ◽  
Simulated System ◽  
Imaging Simulation ◽  
Scan Speed

This paper is devoted to the characterization of the surface defects using a recently developed AFM technique named as frequency and force modulation AFM (FFM-AFM). The simulated system includes a recently developed gold coated AFM probe which interacts with a sample including single-atom vacancy and impurities. In order to examine the behavior of the above system including different transition metals, molecular dynamics (MD) simulation with Sutton-Chen (SC) interatomic potential is used. Along this line, an imaging simulation of the probe and sample is performed, and the effects of the horizontal scan speed, the effective frequency set-point, the cantilever stiffness, the tip-sample rest position and the cantilever quality factor on the resulting images are investigated. Using a proposed optimum controlling scheme for the excitation force amplitude, the cantilever horizontal speed can be maximized.

Characterization and modeling of nanotips fabricated in the field ion microscope

2016 ◽  
Vol 5 (3) ◽  
Author(s):  
Ahmed Ali ◽  
Hassan Barada ◽  
Moh’d Rezeq
Keyword(s):  
Electron Bombardment ◽  
Scanning Probe ◽  
Single Atom ◽  
Local Electron ◽  
Characterization Methods ◽  
Simulation Tools ◽  
Element Simulation ◽  
Electron Microscopes ◽  
Field Ion Microscope

AbstractNanotips are considered significant elements in some of nanotechnology instruments. They are used in scanning probe microscopes and electron microscopes to characterize materials at the nano and atomic scales. Therefore, the size and profile of the nanotip determines the performance of these microscopes. The advancement of nanotip fabrication techniques has enabled the fabrication of ultra-sharp tips and even single-atom tips. However, the characterization of nanotips with an apex of a few nanometers is still premature, while the conventional characterization methods of the tip size, such as the ring counting method, have shown some limitation at this nano scale. In this paper, we review the various nanotip fabrication methods with a focus on the most recent one, which is called the local electron bombardment method. We demonstrate an approach for estimating the nanotip radius with good approximation using ball crystal models. We also model the overall nanotip profile using finite element simulation tools based on the hyperboloidal geometry. The modeling and radius estimation approach is applied on tips fabricated by the local electron bombardment method, which will be explained in detail as well.

scholarly journals Ligand-Metal Charge Transfer Induced via Adjustment of Textural Properties Controls the Performance of Single-Atom Catalysts During Photocatalytic Degradation

2021 ◽  
Author(s):  
Jiaxu Liu ◽  
Yajun Zou ◽  
Daniel Cruz ◽  
Aleksandr Savateev ◽  
Markus Antonietti ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Heterogeneous Catalysts ◽  
Photophysical Properties ◽  
Organic Pollutant ◽  
Textural Properties ◽  
Single Atom ◽  
Single Atoms ◽  
Ligand Charge Transfer ◽  
Kinetic Investigations

Because of their peculiar nitrogen-rich structure, carbon nitrides are convenient polydentate ligands for designing single-atom-dispersed photocatalysts. However, the relation of catalysts textural properties with their photophysical properties and as a result activity in photocatalytic applications is rarely elaborated. Herein we report the preparation and characterization of a series of single-atom heterogeneous catalysts featuring highly-dispersed Ag and Cu species on mesoporous graphitic C<sub>3</sub>N<sub>4</sub>. We show that adjustment of materials textural properties and thereby metal single atoms coordination mode enables ligand-to-metal (LMCT) or ligand-to-metal-to-ligand charge transfer (LMLCT), a property tha was long speculated in single-atom catalysis but never observed. We employ the developed materials in the degradation of organic pollutant under irradiation with visible light. Kinetic investigations under flow conditions show that single atoms of Ag and Cu decrease the amount of toxic organic fragmentation products, while leading to a higher selectivity towards full calcination. The results correlate with the selected mode of charge transfer in the designed photocatalysts and provide a new understanding of the surface state of single-atom catalysts. The concepts can be exploited further to rationally design and optimize other single-atom materials.

scholarly journals Techniques for the characterization of single atom catalysts

RSC Advances ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 1216-1227
Author(s):  
Ping Qi ◽  
Jian Wang ◽  
Xavier Djitcheu ◽  
Dehua He ◽  
Huimin Liu ◽  
...  
Keyword(s):  
Single Atom ◽  
Single Atoms

In this paper, eight methods for identifying single atom catalysts are reviewed. Two of them can directly observe the existence of single atoms, while other methods can provide corresponding evidence of the existence of single atoms.

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