(中南大学 冶金与环境学院，长沙 410083)
摘 要: 以高纯CdCl2、TeCl4和氨水为原料，采用共沉淀-氢气还原法制备出碲化镉粉末。从离子反应平衡角度，对碲和镉共沉淀产物的制备过程进行热力学计算，得到Cd2+-Te4+- NH3-H2O体系金属离子浓度与pH值之间的关系，可以得到在7.0＜pH＜8.0时，体系处于碲和镉的共沉淀区域。结果表明：在Cd2+、Te4+浓度在0.1mol/L的溶液中，加入氨水调节终点pH=7.1时，碲和镉的共沉淀率为99.5%，此时碲镉共沉淀产物为Cd(OH)2、TeO2和少量Cd(NH3)2Cl2的混合物。然后采用氢气还原碲和镉共沉淀产物，在反应温度为400 ℃、保温时间为2.5 h、氢气流量为40 L/h时，成功制备碲化镉粉末。
关键字: 碲化镉粉末；共沉淀；氢气还原
（School of Metallurgy and Environment, Central South University, Changsha 410083, China）
Abstract:CdTe powder was prepared by the coprecipitation-hydrogen reduction method using high purity CdCl2, TeCl4 and ammonia as the raw materials. The preparation process of the Cd and Te coprecipitation product was analyzed by thermodynamic calculation, and the relationship between metal ion concentration and pH at 25 ℃ for Cd2+-Te4+-NH3-H2O system was established. The system is in the co-precipitation area of Cd and Te when 7.0＜pH＜8.0. The results show that the coprecipitation rate of is 99.5% as the concentrations of Cd and Te are 0.1 mol/L when pH=7.1. XRD results show that the coprecipitation product is a mixture of Cd(OH)2, TeO2 and small amount of Cd(NH3)2Cl2. The Cd and Te coprecipitation product is reduced by H2. As the reaction temperature is 400 ℃, isothermal time is 2.5 h, hydrogen flow is 40 L/h, the CdTe powder can be successfully synthesized.
Key words: CdTe powder; coprecipitation; hydrogen reduction
