溶胶-凝胶法制备尖晶石型ZnFe_2O_4粉体的研究

Preparation of Spinel ZnFe_2O_4 Powders by Sol-gel Method

以硝酸铁、硝酸锌为原料,柠檬酸为络合剂,采用溶胶-凝胶法制备了尖晶石型ZnFe_2O_4粉体。通过热重-差热分析(TG-DTA)、X射线衍射仪(XRD)、扫描电镜(SEM)、X射线能谱仪(EDS)、透射电镜(TEM)等方法对制备的ZnFe_2O_4粉体进行了分析测试与表征,并对其合成机理进行探讨。研究表明:滴定溶液的p H=4时最有利于柠檬酸对Fe^(3+)、Zn^(2+)的络合。在600~1000℃下,随着合成温度的提高,制备的ZnFe_2O_4粉体晶型发育逐步完整,确定较好的合成温度为900℃。相同条件下,适当延长保温时间,有助于ZnFe_2O_4粉体的合成。

Spinel ZnFe2O4 powders were prepared by sol-gel method using ferric nitrate and zinc nitratecitric acid as raw materials, citric acid as complexing agent. Spinel ZnFe2O4 powders were characterized using some analytical methods such as TG-DTA, XRD, SEM, EDS and TEM. At the same time, the synthesis mechanism was discussed. The results show that the titration solution of pH =4 is the best condition to the complexation of citric acid to Fe^3＋ and Zn^2 ＋. Among 600-1000 ℃ , with the synthesis temperature increasing, ZnFe2O4 powders grain gradually develop complete. The optimum temperature is 900℃ . Properly prolonging holdingtime is benefit for the formation of ZnFe2O4 powder under the same conditions.