Scanning Tunneling Microscopy Studies of the Electrochemical Reactivity of Thiourea on Au(111) Electrodes

In situ scanning tunneling microscopy (STM) is proposed as an option to investigate the electrochemical reactivity of nontrivial systems. For this purpose the controversial electro-oxidation and electro-reduction of thiourea at Au(111) surfaces under potential control and constant temperature are co...

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Detalles Bibliográficos
Autores: Azzaroni, Omar, Andreasen, Gustavo, Blum, Bárbara, Salvarezza, Roberto Carlos, Arvia, Alejandro Jorge
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2000
País:Argentina
Institución:Universidad Nacional de La Plata
Repositorio:SEDICI (UNLP)
Idioma:inglés
OAI Identifier:oai:sedici.unlp.edu.ar:10915/127154
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/127154
Access Level:acceso abierto
Palabra clave:Ciencias Exactas
Química
scanning tunneling microscopy
nontrivial systems
Descripción
Sumario:In situ scanning tunneling microscopy (STM) is proposed as an option to investigate the electrochemical reactivity of nontrivial systems. For this purpose the controversial electro-oxidation and electro-reduction of thiourea at Au(111) surfaces under potential control and constant temperature are considered. Sequential STM imaging show thiourea adsorption in striped arrays that evolve to a hexagonal close-packed (hcp) structure when the electron surface charge density is decreased. The transient hcp structure is electro-oxidized to formamidine disulfide (FDS) that slowly yields adsorbed sulfur. These results show that STM is a powerful tool to understand the reactivity of adsorbed molecules at conducting surfaces, by sequential imaging at the molecular level.