The dynamics of photopromoted electrons in BiVO4, WO3 and WO3/BiVO4 heterojunction electrodes has been directly probed by transient absorption (TA) midinfrared (mid-IR) spectroscopy in the picosecond to microsecond time range. By comparing the dynamics recorded with the two individual oxides at 2050 cm-1 with that of the heterojunction system after excitation at different wavelengths, electron-transfer processes between selectively excited BiVO4 and WO3 have been directly tracked for the first time. These results support the charge carrier interactions which were previously hypothesized by probing the BiVO4 hole dynamics through TA spectroscopy in the visible range. Nanosecond mid-IR TA experiments confirmed that charge carrier separation occurs in WO3/BiVO4 electrodes under visible light excitation, persisting up to the microsecond timescale.

Photoinduced Charge-Transfer Dynamics in WO3/BiVO4 Photoanodes Probed through Midinfrared Transient Absorption Spectroscopy / I. Grigioni, M. Abdellah, A. Corti, M.V. Dozzi, L. Hammarstrom, E. Selli. - In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. - ISSN 0002-7863. - 140:43(2018 Oct 31), pp. 14042-14045.

Photoinduced Charge-Transfer Dynamics in WO3/BiVO4 Photoanodes Probed through Midinfrared Transient Absorption Spectroscopy

I. Grigioni
Primo
;
M.V. Dozzi;E. Selli
Ultimo
2018

Abstract

The dynamics of photopromoted electrons in BiVO4, WO3 and WO3/BiVO4 heterojunction electrodes has been directly probed by transient absorption (TA) midinfrared (mid-IR) spectroscopy in the picosecond to microsecond time range. By comparing the dynamics recorded with the two individual oxides at 2050 cm-1 with that of the heterojunction system after excitation at different wavelengths, electron-transfer processes between selectively excited BiVO4 and WO3 have been directly tracked for the first time. These results support the charge carrier interactions which were previously hypothesized by probing the BiVO4 hole dynamics through TA spectroscopy in the visible range. Nanosecond mid-IR TA experiments confirmed that charge carrier separation occurs in WO3/BiVO4 electrodes under visible light excitation, persisting up to the microsecond timescale.
Settore CHIM/02 - Chimica Fisica
   Solar driven chemistry: new materials for photo- and electro-catalysis (SMARTNESS)
   MINISTERO DELL'ISTRUZIONE E DEL MERITO
   2015K7FZLH_003

   Nuovi materiali fotocatalittici per la conversione di energia solare basati su etero giunzioni
   FONDAZIONE CARIPLO
   0615-2013

   Laboratorio multifunzionale e centro di formazione per la caratterizzazione e la sperimentazione preapplicativa di smart materials
   SmartMatLab Centre
   FONDAZIONE CARIPLO
   2013-1766
31-ott-2018
8-ott-2018
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/599368
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