Scanning Tunneling Microscopy Observation of Sulfur Electrodeposits on Graphite Single Crystals
The early stages of sulfur deposit growth on highly oriented pyrolytic graphite (HOPG) caused by HS- electrooxidation in a neutral buffered solution have been investigated using electrochemical techniques and ex situ scanning tunneling microscopy (STM). In this system sulfur deposition has been obse...
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| Autores principales: | , , , |
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| Formato: | Articulo |
| Lenguaje: | Español |
| Publicado: |
1996
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| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/126521 https://pubs.acs.org/doi/pdf/10.1021/la940759m?rand=8l3p6czd |
| Aporte de: |
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I19-R120-10915-126521 |
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dspace |
| institution |
Universidad Nacional de La Plata |
| institution_str |
I-19 |
| repository_str |
R-120 |
| collection |
SEDICI (UNLP) |
| language |
Español |
| topic |
Ciencias Exactas Química highly oriented pyrolytic graphite scanning tunneling microscopy graphite single crystals |
| spellingShingle |
Ciencias Exactas Química highly oriented pyrolytic graphite scanning tunneling microscopy graphite single crystals Zubimendi, J. L. Salvarezza, Roberto Carlos Vázquez, L. Arvia, Alejandro Jorge Scanning Tunneling Microscopy Observation of Sulfur Electrodeposits on Graphite Single Crystals |
| topic_facet |
Ciencias Exactas Química highly oriented pyrolytic graphite scanning tunneling microscopy graphite single crystals |
| description |
The early stages of sulfur deposit growth on highly oriented pyrolytic graphite (HOPG) caused by HS- electrooxidation in a neutral buffered solution have been investigated using electrochemical techniques and ex situ scanning tunneling microscopy (STM). In this system sulfur deposition has been observed at −0.80 V vs SCE, i.e. a potential more negative than the reversible potential for the HS-/S reaction. The charge density was equivalent to an average surface coverage by sulfur atoms θ ≅ 1/3 monolayer (ML). Ex situ atomic resolution STM images of the layer electrodeposited at −0.8 V show sulfur submonolayers and large uncovered HOPG domains. Sulfur electroadsorption layers appear as a diluted (√3×√3) surface phase with S atoms atop C atoms of the graphite hexagons and the S−S interatomic distance d(S−S) = 0.42 nm. Further addition of S atoms to a diluted sulfur phase resulted in the formation of sulfur trimers with three S atoms placed atop the three C atoms constituting the graphite hexagons. In this case d(S−S) = 0.24 nm. Neighbor trimers originate a filled hexagonal lattice. Ex situ STM images of overpotential deposited sulfur also show submonolayer sulfur domains with a second hexagonal (√3×√3)R30° sulfur lattice with d(S−S) = 0.42 nm. A further increase of θ produces either a new honeycomb lattice with d(S−S) = 0.24 nm or a rectangular lattice formed by rows of S atoms with d(S−S) = 0.21 nm and row separation d(S−S) = 0.37 nm. |
| format |
Articulo Articulo |
| author |
Zubimendi, J. L. Salvarezza, Roberto Carlos Vázquez, L. Arvia, Alejandro Jorge |
| author_facet |
Zubimendi, J. L. Salvarezza, Roberto Carlos Vázquez, L. Arvia, Alejandro Jorge |
| author_sort |
Zubimendi, J. L. |
| title |
Scanning Tunneling Microscopy Observation of Sulfur Electrodeposits on Graphite Single Crystals |
| title_short |
Scanning Tunneling Microscopy Observation of Sulfur Electrodeposits on Graphite Single Crystals |
| title_full |
Scanning Tunneling Microscopy Observation of Sulfur Electrodeposits on Graphite Single Crystals |
| title_fullStr |
Scanning Tunneling Microscopy Observation of Sulfur Electrodeposits on Graphite Single Crystals |
| title_full_unstemmed |
Scanning Tunneling Microscopy Observation of Sulfur Electrodeposits on Graphite Single Crystals |
| title_sort |
scanning tunneling microscopy observation of sulfur electrodeposits on graphite single crystals |
| publishDate |
1996 |
| url |
http://sedici.unlp.edu.ar/handle/10915/126521 https://pubs.acs.org/doi/pdf/10.1021/la940759m?rand=8l3p6czd |
| work_keys_str_mv |
AT zubimendijl scanningtunnelingmicroscopyobservationofsulfurelectrodepositsongraphitesinglecrystals AT salvarezzarobertocarlos scanningtunnelingmicroscopyobservationofsulfurelectrodepositsongraphitesinglecrystals AT vazquezl scanningtunnelingmicroscopyobservationofsulfurelectrodepositsongraphitesinglecrystals AT arviaalejandrojorge scanningtunnelingmicroscopyobservationofsulfurelectrodepositsongraphitesinglecrystals |
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Repositorios |
| _version_ |
1764820450828877826 |