A series of Pt/Cu/TiO2 photocatalysts, showing very high performance in photocatalytic hydrogen production from methanol/water vapor mixtures, were prepared under mild conditions by Cu(II) grafting on commercial P25 TiO2, with nominal Cu/TiO2 ratios ranging from 0.05 to 0.5 wt.%, followed by 0.5 wt.% Pt nanoparticles deposition by the deposition-precipitation method in the presence of urea. The structural features of the so obtained materials were fully characterized by X-ray absorption spectroscopy, which provided information on the oxidation state of the two metals and on the metal-metal and metal-TiO2 interactions, and by EPR analysis, which evidenced electron transfer phenomena involving copper under irradiation. The photocatalysts showed a volcano-shaped photoactivity trend in hydrogen production with increasing nominal Cu content, the maximum rate of H2 evolution (27.2 mmol h-1 gcat-1) being attained with the photocatalyst containing 0.1 wt.% of copper. In this sample CuO nanoclusters appear to be intimately coordinated with surface Ti atoms in a surface structure that partially stabilizes pre-grafted copper in metallic form, possibly acting as an electron-transfer bridge at the interface between CuO nanoclusters and TiO2. Synergistic effects in H2 photocatalytic production are clearly induced by the co-presence of grafted Cu nanoclusters and Pt nanoparticles on the TiO2 surface, with the copper oxidation state switching under UV-vis irradiation, facilitating electron transfer to adsorbed protons.
High photocatalytic hydrogen production on Cu(II) pre-grafted Pt/TiO2 / M.V. Dozzi, G.L. Chiarello, M. Pedroni, S. Livraghi, E. Giamello, E. Selli. - In: APPLIED CATALYSIS. B, ENVIRONMENTAL. - ISSN 0926-3373. - 209(2017 Jul), pp. 417-428.
High photocatalytic hydrogen production on Cu(II) pre-grafted Pt/TiO2
M.V. Dozzi
;G.L. ChiarelloSecondo
;E. SelliUltimo
2017
Abstract
A series of Pt/Cu/TiO2 photocatalysts, showing very high performance in photocatalytic hydrogen production from methanol/water vapor mixtures, were prepared under mild conditions by Cu(II) grafting on commercial P25 TiO2, with nominal Cu/TiO2 ratios ranging from 0.05 to 0.5 wt.%, followed by 0.5 wt.% Pt nanoparticles deposition by the deposition-precipitation method in the presence of urea. The structural features of the so obtained materials were fully characterized by X-ray absorption spectroscopy, which provided information on the oxidation state of the two metals and on the metal-metal and metal-TiO2 interactions, and by EPR analysis, which evidenced electron transfer phenomena involving copper under irradiation. The photocatalysts showed a volcano-shaped photoactivity trend in hydrogen production with increasing nominal Cu content, the maximum rate of H2 evolution (27.2 mmol h-1 gcat-1) being attained with the photocatalyst containing 0.1 wt.% of copper. In this sample CuO nanoclusters appear to be intimately coordinated with surface Ti atoms in a surface structure that partially stabilizes pre-grafted copper in metallic form, possibly acting as an electron-transfer bridge at the interface between CuO nanoclusters and TiO2. Synergistic effects in H2 photocatalytic production are clearly induced by the co-presence of grafted Cu nanoclusters and Pt nanoparticles on the TiO2 surface, with the copper oxidation state switching under UV-vis irradiation, facilitating electron transfer to adsorbed protons.File | Dimensione | Formato | |
---|---|---|---|
1-s2.0-S0926337317302047-main.pdf
accesso riservato
Tipologia:
Publisher's version/PDF
Dimensione
3.05 MB
Formato
Adobe PDF
|
3.05 MB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Cu_Pt_T__accepted.pdf
accesso aperto
Descrizione: articolo accettato
Tipologia:
Post-print, accepted manuscript ecc. (versione accettata dall'editore)
Dimensione
1.5 MB
Formato
Adobe PDF
|
1.5 MB | Adobe PDF | Visualizza/Apri |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.