Synthesis and gas-sensing properties of CaSnO_3 microcubes

摘要

Uniform CaSnO_3 cubes with pure perovskite phase and edge length of approx 1 mu m have been synthesized by a hydrothermal method followed by calcination at mild temperature (500 deg C). Evolution of the morphologies of the CaSn(OH)_6 microcrystals (precursors to CaSnO_3) as a function of hydrothermal reaction time was investigated based on the observations of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It showed that the CaSn(OH)_6 precursors before hydrothermal reaction mainly consisted of crystals with three-dimensional (3D) symmetrically distributed eight pods, which eventually grew into regular cubic shaped single crystals via the preferred growth direction along <111> in the assistance of polyvinylpyrrolidone (PVP) surfactant and under the supercritical conditions. Moreover, thin film type sensors were fabricated based on the as-synthesized CaSnO_3 microcubes. Gas-sensing characterization indicated that the as-synthesized CaSnO_3 micro-cubes showed high sensitivity and selectivity to ethanol.