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采用水热法将ZnNiAl金属盐溶液混合制得一系列水滑石前驱体,通过在不同温度下焙烧后获得ZnO/NiO/ZnAl_2O_4纳米复合物。利用SEM、HRTEM、TEM、XRD、BET、TG-DTA和UV-VisDRS测试方法对样品进行表征。在模拟太阳光照射下,通过测定甲基橙溶液的光催化降解率来评价样品的光催化活性。研究Zn/Ni/Al摩尔比、焙烧温度等对样品结构组成、形貌及光催化活性的影响。结果表明,相比水滑石前驱体,ZnO/NiO/ZnAl_2O_4纳米复合物有更好的光催化性能,当原料中Zn/Ni/Al摩尔比为2:1:1时,在600°C焙烧所得的催化剂具有最佳光催化活性。在模拟太阳光照射下,60min内对浓度为100mg/L甲基橙的降解率达97.3%,相同条件下远远超过了Degussa P25的活性。并且对ZnO/NiO/ZnAl_2O_4纳米复合物可能的光催化机理进行了探讨。
Hydrothermal method ZnNiAl metal salt solution was mixed to prepare a series of hydrotalcite precursors obtained by calcination at different temperatures to obtain ZnO / NiO / ZnAl_2O_4 nanocomposites. The samples were characterized by SEM, HRTEM, TEM, XRD, BET, TG-DTA and UV-VisDRS methods. The photocatalytic activity of the sample was evaluated by measuring the photocatalytic degradation rate of methyl orange solution under simulated sunlight. The effects of Zn / Ni / Al mole ratio, calcination temperature on the structure, morphology and photocatalytic activity of the samples were investigated. The results show that ZnO / NiO / ZnAl_2O_4 nanocomposite has better photocatalytic activity than hydrotalcite precursor. When the molar ratio of Zn / Ni / Al in the raw material is 2: 1: 1, calcination at 600 ° C Of the catalyst has the best photocatalytic activity. Under the simulated sunlight, the degradation rate of methyl orange at the concentration of 100 mg / L within 60 min was 97.3%, which greatly exceeded the activity of Degussa P25 under the same conditions. The possible photocatalytic mechanism of ZnO / NiO / ZnAl_2O_4 nanocomposites was also discussed.