The WO3/BiVO4 heterojunction is a promising photoanode architecture for water splitting applications. Here, the photoinduced charge carrier dynamics occurring in this system in operando photoelectrochemical conditions, i.e. under an applied anodic potential, are studied through femtosecond transient absorption spectroscopy, to unveil the effects of an applied bias on the early charge carrier dynamics following WO3/BiVO4 excitation. Electrochromic measurements on BiVO4 suggest the presence of intra band gap (IBG) states in this oxide which play an important role in the charge carrier dynamics in the heterojunction. The differences observed in WO3/BiVO4 with respect to individual BiVO4 electrodes are rationalized in terms of the electron equilibration between the two oxides at the heterojunction, dominated by the WO3/BiVO4 interfacial electric field arising from their band energy offset, and the bias-dependent alteration of the IBG states, both determining the rate of hole transfer and accumulation at the BiVO4 surface.

In Operando Photoelectrochemical Femtosecond Transient Absorption Spectroscopy of WO3/BiVO4 Heterojunctions / I. Grigioni, L. Ganzer, F.V.A. Camargo, B. Bozzini, G. Cerullo, E. Selli. - In: ACS ENERGY LETTERS. - ISSN 2380-8195. - 4:9(2019 Sep 13), pp. 2213-2217. [10.1021/acsenergylett.9b01150]

In Operando Photoelectrochemical Femtosecond Transient Absorption Spectroscopy of WO3/BiVO4 Heterojunctions

I. Grigioni
Primo
Membro del Collaboration Group
;
E. Selli
Ultimo
Writing – Review & Editing
2019

Abstract

The WO3/BiVO4 heterojunction is a promising photoanode architecture for water splitting applications. Here, the photoinduced charge carrier dynamics occurring in this system in operando photoelectrochemical conditions, i.e. under an applied anodic potential, are studied through femtosecond transient absorption spectroscopy, to unveil the effects of an applied bias on the early charge carrier dynamics following WO3/BiVO4 excitation. Electrochromic measurements on BiVO4 suggest the presence of intra band gap (IBG) states in this oxide which play an important role in the charge carrier dynamics in the heterojunction. The differences observed in WO3/BiVO4 with respect to individual BiVO4 electrodes are rationalized in terms of the electron equilibration between the two oxides at the heterojunction, dominated by the WO3/BiVO4 interfacial electric field arising from their band energy offset, and the bias-dependent alteration of the IBG states, both determining the rate of hole transfer and accumulation at the BiVO4 surface.
English
Photoelectrocatalysis; water splitting; photoanodes; WO3; BiVO4; transient absorption
Settore CHIM/02 - Chimica Fisica
Articolo
Esperti anonimi
Ricerca di base
Pubblicazione scientifica
   Solar driven chemistry: new materials for photo- and electro-catalysis (SMARTNESS)
   MINISTERO DELL'ISTRUZIONE E DEL MERITO
   2015K7FZLH_003

   Laboratorio multifunzionale e centro di formazione per la caratterizzazione e la sperimentazione preapplicativa di smart materials
   SmartMatLab Centre
   FONDAZIONE CARIPLO
   2013-1766
13-set-2019
19-ago-2019
American Chemical Society
4
9
2213
2217
5
Pubblicato
Periodico con rilevanza internazionale
Aderisco
info:eu-repo/semantics/article
In Operando Photoelectrochemical Femtosecond Transient Absorption Spectroscopy of WO3/BiVO4 Heterojunctions / I. Grigioni, L. Ganzer, F.V.A. Camargo, B. Bozzini, G. Cerullo, E. Selli. - In: ACS ENERGY LETTERS. - ISSN 2380-8195. - 4:9(2019 Sep 13), pp. 2213-2217. [10.1021/acsenergylett.9b01150]
partially_open
Prodotti della ricerca::01 - Articolo su periodico
6
262
Article (author)
Periodico con Impact Factor
I. Grigioni, L. Ganzer, F.V.A. Camargo, B. Bozzini, G. Cerullo, E. Selli
File in questo prodotto:
File Dimensione Formato  
acsenergylett.9b01150.pdf

accesso riservato

Descrizione: articolo pubblicato
Tipologia: Publisher's version/PDF
Dimensione 2.27 MB
Formato Adobe PDF
2.27 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
nz9b01150_si_001.pdf

accesso riservato

Descrizione: Supporting Information
Tipologia: Altro
Dimensione 1.85 MB
Formato Adobe PDF
1.85 MB Adobe PDF   Visualizza/Apri   Richiedi una copia
InOperando_revised.pdf

Open Access dal 14/09/2020

Tipologia: Post-print, accepted manuscript ecc. (versione accettata dall'editore)
Dimensione 1.37 MB
Formato Adobe PDF
1.37 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/672049
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 44
social impact