A water splitting model of Coulomb interactions of its dipole with surface defects of hydrogen implanted perovskite oxide

Abstract

The decay curve of deuterium atoms implanted and the uptake curve of hydrogen atoms in perovskite oxide ceramics by exposure to water vapor at room temperature have been measured by means of the ERD technique with MeV He ion beam. The decay and uptake curves have been phenomenologically analyzed, based on the one way diffusion model for the D–H replacement. The D–H replacement rates in SrCe 0.95Yb 0.05O 3 − δ (bulk), BaCe 0.95Y 0.05O 3 − δ (bulk), BaCe 0.8Sm 0.2O 3 − δ /Ce 0.8Sm 0.2O 2 − δ (thin film) and BaZr 0.84Y 0.16O 3 − δ /8YSZ(thin film) are found to be 6.9 × 10 − 4 /s, 2.0 × 10 − 2 /s, 1.0 × 10 − 1 /s and 3.0 × 10 − 3 /s, respectively. The difference among them are discussed in terms of dipole induced water splitting model induced by Coulomb interactions of dipole charge of water molecule adsorbed at the surface with charges of the surface lattice defects, oxygen vacancy and doped trivalent impurity ions, which introduce donors and acceptors, respectively, thermally ionized at room temperature.