| Abstract: La2CuO4 crystallites were prepared via a sol-gel process using lanthanum nitrate as lanthanum source, citric acid as complexing agent, distilled water as solvent agent, and copper sulfate, copper chloride and copper nitrate as copper source respectively. The influences of different copper sources on thermal property, phase composition, functional group, microstructure and optical property of the as-prepared La2CuO4 crystallites were investigated by thermogravimetric-differential scanning calorimetry, X-ray diffraction, infrared spectrum, transmission electron microscope and UV-Vis-NIR spectrophotometer. The results show that impurity phases will be introduced when copper sulfate or copper chloride is used as copper source. Pure La2CuO4 crystallites can be obtained after calcining at 600 ℃ for 2 h when the copper source is copper nitrate, and the crystallites exhibit an orthogonal structure with grain size of 80~100 nm. By UV-Vis-NIR spectral analysis, the corresponding optical band gap of La2CuO4 crystallites is about 1.193 eV, 1.258 eV and 1.380 eV, when the copper source is copper sulfate, copper chloride and copper nitrate, respectively. |
