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Morphology and mesopores in photoelectrochemically active LaTiO2N single crystals

Published online by Cambridge University Press:  02 February 2016

Simone Pokrant Open the ORCID record for Simone Pokrant [Opens in a new window] ,
Stefan Dilger  and
Steve Landsmann
Simone Pokrant*
Affiliation:
Laboratory Materials for Energy Conversion, Empa, 8600 Dübendorf, Switzerland
Stefan Dilger
Affiliation:
Laboratory Materials for Energy Conversion, Empa, 8600 Dübendorf, Switzerland
Steve Landsmann
Affiliation:
Laboratory Materials for Energy Conversion, Empa, 8600 Dübendorf, Switzerland
*
a)Address all correspondence to this author. e-mail: simone.pokrant@empa.ch
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Abstract

The mesoporous network within photocatalytically and photoelectrochemically active LaTiO2N (LTON) single crystals was investigated by electron microscopy techniques including electron diffraction and scanning transmission electron microscopy imaging. The perovskite-related oxynitride particles were obtained by thermal ammonolysis from monocrystalline micrometer-sized La2Ti2O7 (LTO) particles grown by flux-assisted solid state synthesis. Special attention was paid to the crystal transformation from the monoclinic layered LTO to the orthorhombic perovskite-related LTON within the monocrystalline particles. A detailed analysis of pore directions and pore sizes with respect to the LTON particle shape was performed. The pore formation mechanism taking place during thermal ammonolysis was discussed. Based on the mechanistic understanding of the transformation from the oxide to the oxynitride, a further extension of the mesoporous network toward higher surface areas was proposed for improved photoelectrochemical activity of oxynitride particles, while high crystallinity and particle sizes in the micrometer range continue to enable efficient charge transport.

Keywords

nitrideoxideporosity
Type
Articles
Information
Journal of Materials Research , Volume 31 , Issue 11: Focus Issue: Advanced Materials and Structures for Solar Fuels , 14 June 2016 , pp. 1574 - 1579
Copyright
Copyright © Materials Research Society 2016 

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