La_2CuO_4微晶的溶胶-凝胶法制备及合成活化能

Preparation and Activation Energy of La_2CuO_4 Micro-crystallites Synthesized by Sol–Gel Process

以硝酸镧和硝酸铜为起始原料、水为溶剂、柠檬酸为络合剂,采用溶胶-凝胶法制备La2CuO4微晶。通过热重-差热分析、X射线衍射、红外光谱和透射电子显微镜等表征前驱物凝胶粉体及La2CuO4粉体的热性能、物相组成、官能团及显微结构,用Kissinger法研究La2CuO4微晶的合成活化能。结果表明采用溶胶-凝胶法可以成功制备La2CuO4微晶:600℃煅烧2 h可获得单一物相的La2CuO4;煅烧温度升至700℃后,La2CuO4晶粒形状为正交晶型结构,晶粒尺寸100～120 nm,晶粒分布比较均匀。计算得到La2CuO4微晶的合成活化能为147.0 kJ/mol。

Micro-crystallite La2CuO4 was prepared via a sol–gel process using lanthanum nitrate and cupric nitrate as raw materials,distilled water as solvent,and citric acid as complexing agent.Thermal properties,phase composition,functional group,and micro-structure of the as-prepared La2CuO4 were characterized by thermogravimetric–differential thermal analysis,X-ray diffraction,infra-red spectroscopy,and transmission electron microscopy.Synthesis activation energy of La2CuO4 was investigated by Kissinger method.Results show that La2CuO4 can be successfully prepared by the sol–gel process,and pure La2CuO4 can be obtained by cal-cining at 600 ℃ for 2 h.When calcination temperature is increased to 700 ℃,the La2CuO4 exhibits an orthogonal structure,the grain distribution is uniform and the size is about 100–120 nm.The preparation activation energy of La2CuO4 is calculated to be 147.0 kJ/mol.