材料期刊网

利用溶胶-凝胶法,在室温条件下,以钛酸四丁酯、硝酸镧为主要原料,无水乙醇为溶剂,冰醋酸为抑制剂,浓硝酸为催化剂制得稳定的掺La3＋TiO2溶胶,陈化后的凝胶经不同温度煅烧3h后制得不同掺La3＋量的TiO2。通过XRD对不同煅烧温度及不同掺La3＋量的TiO2进行了表征;以紫外光为光源,研究了掺La3＋TiO2对甲基橙溶液的光降解效果。用化学共沉淀法制备了具有强磁性的Fe3O4水基磁流体,再与La3＋掺杂TiO2进行复合,制备了Fe3O4负载量不同的磁性La3＋掺杂TiO2,研究了Fe3O4负载量不同的La3＋掺杂TiO2对甲基橙的光催化降解效果、磁分离回收率的影响。结果表明,掺La3＋量及煅烧温度对TiO2的晶型、各晶型TiO2的相对含量及对甲基橙的光降解效果均有影响。La3＋掺杂TiO2比纯TiO2显示出更强的光催化性能,掺La3＋量2%,热处理温度450℃的La3＋掺杂TiO2光催化活性最高。Fe3O4负载量为10%的Fe3O4/La3＋-TiO2对甲基橙的降解率8h时为99.4%;磁分离回收率达97.39%。

With sol-gel method, La3＋ -doped TiO2 sol was synthedized using tetrabutyl titanate and lanthanum nitrate as main raw materials, anhydrous ethanol as the solvent, glacial acetic acid as the inhibitor, concentrated nitric acid as the catalyst. The gel was calcined for 3h at different temperature, and then TiO2 powder with dif-ferent amounts of La3＋ -doped was obtained. All samples of methyl orange on La3＋-doped TiO2 was studied using UV as light source. Water-based magnetic fluids FeaO4 was prepared by chemical coprecipitation method, La3＋ -doped TiO2 with different mass fraction of Fe3O4 were prepared by La3＋ doped TiO2 compounding with magnetic fluids Fea 04, and the photodegradation effect of methyl orange on La3＋ -doped TiO2 with different mass fraction of Fe3O4 and magnetic separation recovery rate were studied. The results showed that the amount of La3＋ -doped and the calcine temperature had impacts on the crystal phase of TiO2, relative content of different crystal phase TiO2 and the photodegradation effect on methyl orange, the photocatalytic activity of La3＋ -doped TiO2 was superior to the pure TiO2, and the photocat alytic activity of La3＋ -doped TiO2 was highest in all samples when the amount of La3＋ -doped was 2.0%, heat treatment temperature was 450°C. When the mass fraction of Fe3O4 was 10%, the photodegradation effect of methyl orange on La3＋ -doped TiO2 with increased rapidly with degradation time increasing, reached to 99.4%when degradation time was 8h, and the magnetic separation recovery rate reached to 97.39 %.