论文部分内容阅读
采用柠檬酸和硬脂酸作为螯合剂,通过溶胶-凝胶过程制备不同凝聚态结构的CuAl2O4粉体,利用DTA-TG分析它们形成过程动力学,采用XRD表征不同温度阶段下形成的产物,并通过TEM观察其结构形貌。结果表明,柠檬酸作螯合剂时,700℃下保持2h可形成纯相尖晶石结构CuAl2O4晶体,为无规则颗粒状,尺寸大约10～25nm,分散性较好;硬脂酸做螯合剂时,1000℃下保持2h才可形成纯相尖晶石结构CuAl2O4晶体,颗粒尺寸为40～90nm,团聚现象严重。通过在高压汞灯照射下(λ>400nm)对甲基橙的光催化降解数据表明,柠檬酸螯合剂制备的纳米粉体的光催化活性高于硬脂酸制备的纳米粉体的光催化活性,对甲基橙的2h脱色率分别为98%和85%。
CuAl2O4 powders with different condensed structures were prepared by sol-gel process using citric acid and stearic acid as chelating agents. Their kinetics were analyzed by DTA-TG. The products formed under different temperature stages were characterized by XRD Morphology was observed by TEM. The results showed that when citric acid was used as the chelating agent, the pure CuAl2O4 spinel structure was formed at 700 ℃ for 2h, which was randomly granular and about 10-25nm in size with good dispersibility. When stearic acid was used as the chelating agent The pure CuAl2O4 spinel structure can be formed after holding at 1000 ℃ for 2h. The particle size is 40 ~ 90nm and the agglomeration is serious. The photocatalytic degradation of methyl orange by high pressure mercury lamp (λ> 400nm) showed that the photocatalytic activity of nanopowders prepared by citric acid chelating agent was higher than that of stearic acid nanopowders , 2h on methyl orange decolorization rates were 98% and 85%.