Use of interplay between A-site non-stoichiometry and hydroxide doping to deliver novel proton-conducting perovskite oxides
Date
07/10/2021Author
Grant ID
EP/R023522/1
EP/R023751/1
ep/l017008/1
EP/P007821/1
Keywords
Metadata
Show full item recordAbstract
The magnitude of ionic conductivity is known to depend upon both mobility and number of available carriers. For proton conductors, hydration is a key factor in determining the charge–carrier concentration in ABO3 perovskite oxides. Despite the high reported proton mobility of calcium titanate (CaTiO3), this titanate perovskite has thus far been regarded as a poor proton conductor due to the low hydration capability. Here, the enhanced proton conductivity of the defective calcium titanate Ca0.92TiO2.84(OH)0.16 prepared by replacing lattice oxygens with hydroxyl groups via a solvothermal route is shown. Conductivity measurements in a humidified Ar atmosphere reveal that, remarkably, this material exhibits one order of magnitude higher bulk conductivity (10−4 Scm−1 at 200 °C) than hydrated stoichiometric CaTiO3 prepared by traditional solid-state synthesis due to the higher concentration of protonic defects and variation in the crystal structure. The replacement of Ca2+ by Ni2+ in the Ca1−xTi1O3−2x(OH)2x, which mostly exsolve metallic Ni nanoparticles along orthorhombic (100) planes upon reduction, is also demonstrated. These results suggest a new strategy by tailoring the defect chemistry via hydration or cation doping followed by exsolution for targeted energy applications.
Citation
Lee , J , Naden , A B , Savaniu , C D , Connor , P A , Payne , J L , Skelton , J , Gibbs , A , Hui , J , Parker , S & Irvine , J T S 2021 , ' Use of interplay between A-site non-stoichiometry and hydroxide doping to deliver novel proton-conducting perovskite oxides ' , Advanced Energy Materials , vol. 11 , no. 37 , 2101337 . https://doi.org/10.1002/aenm.202101337
Publication
Advanced Energy Materials
Status
Peer reviewed
ISSN
1614-6832Type
Journal article
Rights
Copyright © 2021 The Authors. Advanced Energy Materials published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Description
Funding: UK Engineering and Physical Sciences Research Council (Grant Number(s): EP/R023522, EP/R023751, EP/L017008, EP/P007821, EP/L000202, EP/R029431); Diamond Light Source (Grant Number(s): SP17198-8); Rutherford Appleton Laboratory (Grant Number(s): RB1920629).Collections
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