Use of Interplay between A?Site Non?Stoichiometry and Hydroxide Doping to Deliver Novel Proton?Conducting Perovskite Oxides

The magnitude of ionic conductivity is known to depend upon both mobility and number available carriers. For proton conductors, hydration a key factor in determining the charge–carrier concentration ABO3 perovskite oxides. Despite high reported calcium titanate (CaTiO3), this has thus far been regarded as poor conductor due low capability. Here, enhanced defective Ca0.92TiO2.84(OH)0.16 prepared by replacing lattice oxygens with hydroxyl groups via solvothermal route shown. Conductivity measurements humidified Ar atmosphere reveal that, remarkably, material exhibits one order higher bulk (10?4 Scm?1 at 200 °C) than hydrated stoichiometric CaTiO3 traditional solid-state synthesis protonic defects variation crystal structure. replacement Ca2+ Ni2+ Ca1?xTi1O3?2x(OH)2x, which mostly exsolve metallic Ni nanoparticles along orthorhombic (100) planes reduction, also demonstrated. These results suggest new strategy tailoring defect chemistry or cation doping followed exsolution for targeted energy applications.