Marikutsa Artem, Rumyantseva Marina, Baranchikov Alexander, Gaskov Alexander
Chemistry Department, Moscow State University, Leninskie Gory 1-3, Moscow 119991, Russia.
Kurnakov Institute of General and Inorganic Chemistry, Leninskiy prospect 31, Moscow 119991, Russia.
Materials (Basel). 2015 Sep 18;8(9):6437-6454. doi: 10.3390/ma8095311.
Nanocrystalline perovskite-type BaSnO₃ was obtained via microwave-assisted hydrothermal route followed by annealing at variable temperature. The samples composition and microstructure were characterized. Particle size of 18-23 nm was unaffected by heat treatment at 275-700 °C. Materials DC-conduction was measured at variable temperature and oxygen concentration. Barium stannate exhibited -type semiconductor behavior at 150-450 °C with activation energy being dependent on the materials annealing temperature. Predominant ionosorbed oxygen species types were estimated. They were shown to change from molecular to atomic species on increasing temperature. Comparative test of sensor response to various inorganic target gases was performed using nanocrystalline SnO₂-based sensors as reference ones. Despite one order of magnitude smaller surface area, BaSnO₃ displayed higher sensitivity to SO₂ in comparison with SnO₂. DRIFT spectroscopy revealed distinct interaction routes of the oxides surfaces with SO₂. Barium-promoted sulfate formation favoring target molecules oxidation was found responsible for the increased BaSnO₃ sensitivity to ppm-range concentrations of SO₂ in air.
通过微波辅助水热法制备了纳米晶钙钛矿型BaSnO₃，随后在不同温度下进行退火处理。对样品的成分和微观结构进行了表征。18 - 23 nm的粒径不受275 - 700 °C热处理的影响。在不同温度和氧浓度下测量了材料的直流导电性。锡酸钡在150 - 450 °C表现出n型半导体行为，其活化能取决于材料的退火温度。估计了主要的离子吸附氧物种类型。结果表明，随着温度升高，它们从分子物种转变为原子物种。以纳米晶SnO₂基传感器为参考，对各种无机目标气体的传感器响应进行了对比测试。尽管BaSnO₃的表面积比SnO₂小一个数量级，但与SnO₂相比，它对SO₂表现出更高的灵敏度。漫反射红外傅里叶变换光谱（DRIFT）揭示了氧化物表面与SO₂的不同相互作用途径。发现促进钡的硫酸盐形成有利于目标分子氧化，这是BaSnO₃对空气中ppm级浓度的SO₂灵敏度增加的原因。
