焙烧温度对ZnO粉体结晶及光学性能的影响

以草酸铵和醋酸锌为原料，采用直接沉淀法制备ZnO粉体，考察了焙烧温度对粉体结晶和光学性能的影响。 采用热重分析（TGA-DTA）、X射线衍射、紫外-可见漫反射（UV-Vis）、荧光分光光度计（FS）和扫描电子显微镜（SEM）等方法对样品进行了分析。 结果表明，制备的前驱物为C2O4Zn·2H2O，最低焙烧温度400 ℃，随着焙烧温度的提高，粉体结晶度提高，一次粒径增大；600 ℃焙烧后有较强紫外发光峰，粉体由200 nm的粒子排列成层叠状；900 ℃焙烧后有较强可见发光峰，粉体粒子大于500 nm，团聚严重；粉体有较强的紫外吸收，吸收峰有蓝移。

Effects of Calcination Temperature on Crystallization and Optical Properties of ZnO Powder

ZnO powder was obtained by conventional precipitation method using ammonium oxalate and zinc acetate as raw materials. The effects of calcination temperature on the crystallization and fluorescent properties of the product were investigated. The powders were characterized and analyzed by TGA-DTA, XRD, UV-Vis, FS and SEM, respectively. The results show that the precursor is C2O4Zn·2H2O and its minimum calcination temperature is 400 ℃. With the increase of the calcination temperature, the crystallinity of the product is enhanced and the primary particle size tends to grow. The powder is consisted of 200 nm lamellar particles and has a strong ultraviolet luminescence peak after 600 ℃ calcination. When the calcination temperature was increased to 900 ℃, the product became highly agglomerated with particle size larger than 500 nm. In addition, the ZnO powder shows a strong ultraviolet absorption with a blue shift of absorption peak.