Reduction of Ln2Ti2O7 Layered Perovskites: ...
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Article dans une revue scientifique: Article original
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Title :
Reduction of Ln2Ti2O7 Layered Perovskites: A Survey of the Anionic Lattice, Electronic Features, and Potentials
Author(s) :
Pussacq, Tanguy [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Kabbour, Houria [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Colis, Silviu [Auteur]
Institut de Physique et Chimie des Matériaux de Strasbourg [IPCMS]
Vezin, Herve [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Saitzek, Sebastien [Auteur]
Unité de Catalyse et de Chimie du Solide (UCCS) - UMR 8181
Gardoll, Olivier [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Tassel, Cédric [Auteur]
Kageyama, Hiroshi [Auteur]
Laberty-Robert, Christel [Auteur]
Mentre, Olivier [Auteur]
Unité de Catalyse et de Chimie du Solide (UCCS) - UMR 8181
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Kabbour, Houria [Auteur]

Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Colis, Silviu [Auteur]
Institut de Physique et Chimie des Matériaux de Strasbourg [IPCMS]
Vezin, Herve [Auteur]

Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Saitzek, Sebastien [Auteur]

Unité de Catalyse et de Chimie du Solide (UCCS) - UMR 8181
Gardoll, Olivier [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181
Tassel, Cédric [Auteur]
Kageyama, Hiroshi [Auteur]
Laberty-Robert, Christel [Auteur]
Mentre, Olivier [Auteur]

Unité de Catalyse et de Chimie du Solide (UCCS) - UMR 8181
Journal title :
Chemistry of Materials
Volume number :
29
Pages :
1047-1057
Publication date :
2017-01-12
HAL domain(s) :
Chimie/Chimie inorganique
English abstract : [en]
The reduction of the layered perovskites Ln2Ti2O7 (LnTO, with lanthanide Ln = La, Pr, or Nd) was studied with the aim of shifting the ultraviolet (UV) photocalytic activity for water splitting in the visible range by Ti3+ ...
Show more >The reduction of the layered perovskites Ln2Ti2O7 (LnTO, with lanthanide Ln = La, Pr, or Nd) was studied with the aim of shifting the ultraviolet (UV) photocalytic activity for water splitting in the visible range by Ti3+ donor doping. For all phases, after reduction by CaH2, the absorbance is extended beyond the UV–visible region, giving rise to a gaplike edge in the mid-infrared at ∼0.4 eV with a dark coloration of the samples. When the precursor with Ln = La was reduced under a high-temperature H2 flow, we found a progressive nanotexturation down to 300 nm, which is responsible for a degree of Ti3+ segregation at the surface. Magnetic measurements, thermal analysis, and powder neutron diffraction reveal that the samples reduced by both routes have a similar amount of anion vacancy with δ = 0.27 (in La2Ti2O7−δ). It represents a limited topotactic reduction stage, prior to the reconstructive reduction into La5Ti3.8+5O17 observed under more severe reducing conditions. For the sample reduced by CaH2, a minor amount of hydride appears to be incorporated (∼0.02 H per FU), with Ti3+···H– bonding observed by hyperfine sublevel correlation spectroscopy electron paramagnetic resonance and density functional theory calculations. Preliminary electrocatalysis tests show a promising anodic activity for water splitting hydrogen evolution with a voltage onset as low as 0.6 V versus the reversible hydrogen electrode.Show less >
Show more >The reduction of the layered perovskites Ln2Ti2O7 (LnTO, with lanthanide Ln = La, Pr, or Nd) was studied with the aim of shifting the ultraviolet (UV) photocalytic activity for water splitting in the visible range by Ti3+ donor doping. For all phases, after reduction by CaH2, the absorbance is extended beyond the UV–visible region, giving rise to a gaplike edge in the mid-infrared at ∼0.4 eV with a dark coloration of the samples. When the precursor with Ln = La was reduced under a high-temperature H2 flow, we found a progressive nanotexturation down to 300 nm, which is responsible for a degree of Ti3+ segregation at the surface. Magnetic measurements, thermal analysis, and powder neutron diffraction reveal that the samples reduced by both routes have a similar amount of anion vacancy with δ = 0.27 (in La2Ti2O7−δ). It represents a limited topotactic reduction stage, prior to the reconstructive reduction into La5Ti3.8+5O17 observed under more severe reducing conditions. For the sample reduced by CaH2, a minor amount of hydride appears to be incorporated (∼0.02 H per FU), with Ti3+···H– bonding observed by hyperfine sublevel correlation spectroscopy electron paramagnetic resonance and density functional theory calculations. Preliminary electrocatalysis tests show a promising anodic activity for water splitting hydrogen evolution with a voltage onset as low as 0.6 V versus the reversible hydrogen electrode.Show less >
Language :
Anglais
Peer reviewed article :
Oui
Audience :
Internationale
Popular science :
Non
Administrative institution(s) :
ENSCL
Université de Lille
CNRS
Centrale Lille
Univ. Artois
Université de Lille
CNRS
Centrale Lille
Univ. Artois
Collections :
Research team(s) :
Couches minces & nanomatériaux (CMNM)
Matériaux inorganiques, structures, systèmes et propriétés (MISSP)
Matériaux inorganiques, structures, systèmes et propriétés (MISSP)
Submission date :
2019-09-25T14:05:46Z
2021-07-07T15:43:49Z
2021-07-07T15:43:49Z
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