On the UV-Visible Light Synergetic Mechanisms in Au/TiO2Hybrid Model Nanostructures Achieving Photoreduction of Water

Maria Isabel Mendoza-Diaz, Jérémy Cure, Mehdi Djafari Rouhani, Kui Tan, Sai Gourang Patnaik, David Pech, Manuel Quevedo-Lopez, Teresa Hungria, Carole Rossi, Alain Estève*

*Autor correspondiente de este trabajo

Resultado de la investigación: Capítulo del libro/informe/acta de congresoContribución a la conferenciarevisión exhaustiva

Resumen

This paper reports the synergetic effects of UV and visible light irradiation on the photocatalytic activity of well-defined nanostructures composed of TiO2films and Au nanoparticles (NPs). New insights into electronic as well as chemical processes that drive water decomposition were obtained by varying the position of the NPs on top and at different depths inside the semiconductor film. This work highlights the synergetic effect of UV and visible light on the photocatalytic activity of all the Au-containing structures: hydrogen produced under UV + Vis light shows 100% enhancement compared to the net production obtained under either UV or visible light alone. The systems where Au NPs are embedded in TiO2outperform the one where NPs are positioned on the surface, indicating that the water-splitting reaction occurs primarily on the TiO2surface rather than on the metal. Photocurrent and photocatalytic activity measurements under UV (353-403 nm), visible (400-1100 nm), and UV + Vis (300-1100 nm) light revealed the synergetic contribution of UV and Vis light. Indeed, the plasmonic Au NPs create an intense oscillating electric field at the Au NPs/semiconductor interface (visible light contribution); this mechanism coupled with the Schottky barrier formation generates hot electrons resulting in a better photoexcited charge separation. In addition, contrary to what is generally assumed, charge injection by the plasmon from the metal into the semiconductor plays a marginal role in the hydrogen evolution reaction. Furthermore, this paper highlights the positive impact of the semiconductor crystallinity surrounding the metal particles to avoid the charge carrier recombination and the importance of a surface free of oxygen vacancies, whose presence can inhibit the water decomposition.

Idioma originalInglés
Título de la publicación alojada2021 AIChE Annual Meeting
EditorialAmerican Institute of Chemical Engineers
ISBN (versión digital)9781713852834
DOI
EstadoPublicada - 2021
Evento2021 AIChE Annual Meeting - Boston, Virtual, Estados Unidos
Duración: 15 nov 202119 nov 2021

Serie de la publicación

NombreAIChE Annual Meeting, Conference Proceedings
Volumen2021-November

Conferencia

Conferencia2021 AIChE Annual Meeting
País/TerritorioEstados Unidos
CiudadBoston, Virtual
Período15/11/2119/11/21

Nota bibliográfica

Publisher Copyright:
© 2021 American Institute of Chemical Engineers. All rights reserved.

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