Thin film preparation and hydrogen pumping characteristics of BaCe0.8Y0.2O3−δ

Thin films of BaCe0.8Y0.2O3−δ (BCY) were prepared by a colloidal spray deposition method. Dense, crack-free BCY films with thickness of ≈10 μm and a grain size of 2-7 μm were successfully deposited on porous NiO/BCY substrates. Scanning electron microscopy showed that the films have uniform thickness and are well bonded to the substrate. The hydrogen pumping characteristics of the films were investigated at temperatures of 500-700 °C, and show that the hydrogen evolution rates agree very well with those expected by Faraday's law up to the current limit (2 A) of the galvanostat. A maximum current density of 2.1 A/cm2 was measured at 700 °C with an applied voltage of 1 V.