The hybrid systems composed by [FeFe]-hydrogenase anchored to the surface of three distinct types of TiO2 (anatase) have been investigated using Electron Paramagnetic Resonance (EPR) spectroscopy in dark and under illumination. The three supports were bare TiO2, nitrogen doped TiO2 (N-TiO2) and a sub-stoichiometric form of the same oxide (TiO2x) exhibiting blue color. EPR spectroscopy has shown that the electrons photogenerated by irradiation of the supports are stabilised by the solid forming Ti3þ paramagnetic ions while, in the case of the hybrid systems electrons are scavenged by the anchored protein becoming available for Hþ reduction. The ability of the three hybrid systems in hydrogen production under solar light illumination has been compared. The formation of H2 is higher for the system containing N-TiO2 (yellow) with respect to that based on the bare oxide (white) indicating that the visible light absorbed, due to the presence of N states, is actually exploited for hydrogen production. The system containing reduced blue TiO2, in spite of its deep coloration, is less active suggesting that a specific type of visible light absorption is needed to produce photoexcited electrons capable to interact with the anchored protein.

Electron transfer and H2 evolution in hybrid systems based on [FeFe]-hydrogenase anchored on modified TiO2

POLLIOTTO, VALERIA;MORRA, SIMONE;LIVRAGHI, Stefano;VALETTI, Francesca;GILARDI, Gianfranco;GIAMELLO, Elio
2016

Abstract

The hybrid systems composed by [FeFe]-hydrogenase anchored to the surface of three distinct types of TiO2 (anatase) have been investigated using Electron Paramagnetic Resonance (EPR) spectroscopy in dark and under illumination. The three supports were bare TiO2, nitrogen doped TiO2 (N-TiO2) and a sub-stoichiometric form of the same oxide (TiO2x) exhibiting blue color. EPR spectroscopy has shown that the electrons photogenerated by irradiation of the supports are stabilised by the solid forming Ti3þ paramagnetic ions while, in the case of the hybrid systems electrons are scavenged by the anchored protein becoming available for Hþ reduction. The ability of the three hybrid systems in hydrogen production under solar light illumination has been compared. The formation of H2 is higher for the system containing N-TiO2 (yellow) with respect to that based on the bare oxide (white) indicating that the visible light absorbed, due to the presence of N states, is actually exploited for hydrogen production. The system containing reduced blue TiO2, in spite of its deep coloration, is less active suggesting that a specific type of visible light absorption is needed to produce photoexcited electrons capable to interact with the anchored protein.
41
25
10547
10556
http://www.journals.elsevier.com/international-journal-of-hydrogen-energy/
Doped-TiO2; Electron transfer; EPR; H2 evolution; [FeFe]-hydrogenase; Renewable Energy, Sustainability and the Environment; Fuel Technology; Condensed Matter Physics; Energy Engineering and Power Technology
Polliotto, Valeria; Morra, Simone; Livraghi, Stefano; Valetti, Francesca; Gilardi, Gianfranco; Giamello, Elio
File in questo prodotto:
File Dimensione Formato  
HY-TiO2_per IRIS_4aperto.pdf

Accesso aperto con embargo fino al 01/06/2017

Descrizione: Articolo principale
Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 1.1 MB
Formato Adobe PDF
1.1 MB Adobe PDF Visualizza/Apri
2016_hydrogenase-TiO2.pdf

Accesso riservato

Tipo di file: PDF EDITORIALE
Dimensione 1.16 MB
Formato Adobe PDF
1.16 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

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: http://hdl.handle.net/2318/1620064
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 19
  • ???jsp.display-item.citation.isi??? 19
social impact