多孔CeO2膜的制备及其光谱性能

以铈箔为原料，采用阳极氧化法和热处理法制备多孔的CeO₂膜。将阳极氧化铈膜分别在400，500和800 ℃下进行热处理，分别研究阳极氧化铈膜的晶体结构、组成和表面形貌，分别研究多孔的CeO₂膜红外光谱特征吸收和热膨胀性能。阳极氧化铈膜是Ce(OH)₃，CeF₃，Ce₂O₃，CeO₂和Ce的混合膜，并吸附水和乙二醇，其中Ce(OH)₃，CeF₃，Ce₂O₃分别为六方晶型结构，CeO₂和Ce分别为立方晶型结构。阳极氧化铈膜中的Ce(OH)₃，Ce₂O₃和Ce分别在400和500 ℃进行热处理时可能分别转变为CeO₂，分别在400和500 ℃热处理后的膜为CeF₃和CeO₂的混合膜。阳极氧化铈膜中的Ce(OH)₃，CeF₃，Ce₂O₃和Ce在800 ℃进行热处理时可能分别转变为CeO₂，在800 ℃热处理后的膜为CeO₂膜。该CeO₂膜是多孔的膜，且孔为直孔，在1 600～4 000 cm-1范围内具有强吸收。该CeO₂膜在170～900 ℃范围内热膨胀系数变化不大，该膜的热稳定性较好。

Preparation of the Porous CeO2 Film and Its Spectral Properties

The porous CeO₂ films were prepared with anodization and heat treating method with cerium foils as raw materials. The anodic cerium oxide films were heat treated at 400, 500 and 800 ℃ respectively. The crystal structures, compositions, surface morphologies of the cerium dioxide films were investigated, respectively. The properties of IR characteristic absorption and thermal expansion of the porous CeO₂ film were investigated respectively. The anodic cerium oxide film is composed of Ce(OH)₃, CeF₃, CeO₂, Ce₂O₃ and Ce, and the crystal structures of Ce(OH)₃, CeF₃, Ce₂O₃ and CeO₂, Ce are hexagonal and cubic respectively. Water and ethylene glycol are adsorbed on the anodic cerium oxide film. When the anodic cerium oxide films were heat treated at 400 and 500 ℃ respectively, Ce(OH)₃, Ce₂O₃ and Ce in the anodic cerium oxide film may be converted to CeO₂, and the heat treated films are composed of CeF₃ and CeO₂ respectively. When the anodic cerium oxide film was heat treated at 800 ℃, Ce(OH)₃, CeF₃, Ce₂O₃ and Ce in the anodic cerium oxide film are converted to CeO₂, and the heat treated film is composed of CeO₂. The heat treated anodic cerium oxide film of heat treatment at 800 ℃ is CeO₂ film. The CeO₂ film is porous film, and the hole is a straight hole. The porous CeO₂ film has strong absorption in the range of 1 600～4 000 cm-1. The coefficients of thermal expansion of the porous CeO₂ film are almost constant in the range of 170～900 ℃. The porous CeO₂ film has good thermal stability.