(中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410083)
摘 要: 以高純CdCl2、TeCl4和氨水為原料，采用共沉淀-氫氣還原法制備出碲化鎘粉末。從離子反應(yīng)平衡角度，對碲和鎘共沉淀產(chǎn)物的制備過程進(jìn)行熱力學(xué)計(jì)算，得到Cd2+-Te4+- NH3-H2O體系金屬離子濃度與pH值之間的關(guān)系，可以得到在7.0＜pH＜8.0時(shí)，體系處于碲和鎘的共沉淀區(qū)域。結(jié)果表明：在Cd2+、Te4+濃度在0.1mol/L的溶液中，加入氨水調(diào)節(jié)終點(diǎn)pH=7.1時(shí)，碲和鎘的共沉淀率為99.5%，此時(shí)碲鎘共沉淀產(chǎn)物為Cd(OH)2、TeO2和少量Cd(NH3)2Cl2的混合物。然后采用氫氣還原碲和鎘共沉淀產(chǎn)物，在反應(yīng)溫度為400 ℃、保溫時(shí)間為2.5 h、氫氣流量為40 L/h時(shí)，成功制備碲化鎘粉末。
關(guān)鍵字: 碲化鎘粉末；共沉淀；氫氣還原
（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
