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 C 2 O 4 Zn·2H 2 O 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.