Photoinduced Charge Transfer and Trapping on Single Gold Metal Nanoparticles on TiO2

We present a study of the effect of gold nanoparticles (Au NPs) on TiO2 on charge generation and trapping during illumination with photons of energy larger than the substrate band gap. We used a novel characterization technique, photoassisted Kelvin probe force microscopy, to study the process at th...

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Detalles Bibliográficos
Autores: Luna, Mónica, Barawi, Mariam, Gómez-Moñivas, Sacha, Colchero, Jaime, Rodríguez-Peña, Micaela, Yang, Shanshan, Zhao, Xiao, Lu, Yi-Hsien, Chintala, Ravi, Reñones, Patricia, Altoe, Virginia, Martínez Orellana, Lidia, Huttel, Yves, Kawasaki, Seiji, Weber-Bargioni, Alexander, Peña O'Shea, Víctor A. de la, Yang, Peidong, Ashby, Paul D., Salmerón, Miquel
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/260941
Acceso en línea:http://hdl.handle.net/10261/260941
Access Level:acceso abierto
Palabra clave:Charge transfer
Photovoltage
Kelvin probe force microscopy
Atomic force microscopy
TiO2
Metal nanoparticles
Photoelectrocatalysis
Descripción
Sumario:We present a study of the effect of gold nanoparticles (Au NPs) on TiO2 on charge generation and trapping during illumination with photons of energy larger than the substrate band gap. We used a novel characterization technique, photoassisted Kelvin probe force microscopy, to study the process at the single Au NP level. We found that the photoinduced electron transfer from TiO2 to the Au NP increases logarithmically with light intensity due to the combined contribution of electron-hole pair generation in the space charge region in the TiO2-air interface and in the metal-semiconductor junction. Our measurements on single particles provide direct evidence for electron trapping that hinders electron-hole recombination, a key factor in the enhancement of photo(electro)catalytic activity.