纳米钛酸锶钡粉体制备及其对水中Cd2+吸附行为

采用草酸盐化学共沉淀法制备了草酸氧钛锶钡前驱体，通过905℃高温煅烧，制得了高纯纳米钛酸锶钡，并利用SEM、TEM、FT-IR和XRD对其进行了表征;并将该粉体应用于水中重金属镉离子的吸附.结果表明：该法合成的钛酸锶钡粉体为球形，钙钛矿结构，平均粒径为36 nm.对水中的镉离子具有较强的吸附能力，其吸附量与介质的pH值有密切关系，吸附动力学符合Langmuir和Bangham速率方程所描述的规律;吸附等温线较好地符合Langmuir和Freundlich等温方程，吸附行为是自发的、放热的物理吸附过程.

Preparation of nanometer-sized BST powder and its adsorption behavior for cadmium ion

The barium-strontium titanyl oxalate (BSTO) precursor powder was prepared successfully by using the simple oxalate chemical coprecipitation method.The pyrolysis of BSTO at 905℃ in air produced barium-strontium titanate (BST) powder.BST powder was characterized with SEM, TEM，XRD and FT-IR, which revealed that the powder was spherical, highly pure, perovskite, and the average particle diameter was 36 nm.The adsorption behavior of nanometer-sized BST powder for cadmium ion in water was investigated with FAAS.It was found that the powder had adsorption capacity towards cadmium ion and the amount of adsorption was closely related to the pH of water.The adsorption dynamics followed the rate equation of Langmuir and Bangham.The adsorption isotherm accorded with Langmuir and Freundlich equation.The adsorption was characterized by physisorption with spontaneous heat release.