钙钛矿型LaxSr1－xNi1－yCoyO3光电催化活性研究

用甘氨酸-硝酸盐燃烧合成法, 制备La_xSr_1－xNi_1－yCo_yO₃复合氧化物的陶瓷粉末, 对钙钛矿氧化物进行了XRD结构分析. 在通氧或不通氧下测试氧还原和氧析出的循环伏安曲线. 结果表明: 该氧电极具有双功能催化特性, 但不完全可逆. 利用汞灯作为激发光源, 进行几种水溶性染料和五种混合染料光解实验, 利用紫外-可见、红外以及人工神经网络光度法研究La_xSr_1－xNi_1－yCo_yO₃的催化性能. 结果表明: La_xSr_1－xNi_1－yCo_yO₃ (x＝0.7, 0.9, 1; y＝0.3, 0.75)复合氧化物都具有较强光催化特性; La_xSr_1－xNi_1－yCo_yO₃的光催化活性高于La_xSr_1－xNiO₃, 这与B位离子(Ni^2—, Co^2－)的电子构型有关; Co^2＋的加入可使La_xSr_1－xNiO₃的光催化活性有所提高.

Study on Photo-Electro Catalytic Activity of Perovskite Type Oxides LaxSr1-xNi1-yCoyO3

A new combustion synthesis method, the glycine-nitrate process, has been used to prepare com- plex oxide ceramic powders of La_xSr_(1-x)Ni_(1-y)Co_yO_3. A series of perovskite oxides were characterized by XRD. The cyclic voltammetry curves of oxygen reduction and oxygen release were obtained with and with- out flowing oxygen. The result shows that oxygen electrodes have bifunctional catalysis activity but it is not completely reversible. The degradation experiment of various water-soluble dyestuff and five-component mixed dyestuff was performed by photo catalytic methods. A fluorescent Hg lamp was used as irradiation source. The catalytic activity of La_xSr_(1-x)Ni_(1-y)Co_yO_3 was studied with UV-Vis, IR and artificial nerve net- work and spectrophotometry. The results show that the complex oxides of La_xSr_(1-x)Ni_(1-y)Co_yO_3 (x=0.7, 0.9; y=0.3, 0.75) presented evident photo catalytic activity. The La_xSr_(1-x)Ni_(1-y)Co_yO_3 showed stronger activities than La0.7Sr0.3NiO3, and this is attributed to the unique electronic structure of the ion B (Ni3+, Co3+). The results showed that adding Co2+ can sharply improve the photo-electro catalytic activity of La_xSr_(1-x)- Ni_(1-y)Co_yO_3.