溶剂热结晶法制备纳米氧化铁的工艺研究

Study on Preparation of Nano-Fe_2O_3 by Thermal-Crystallization Method

采用溶剂热结晶法制备工艺,以硫酸亚铁(FeSO_4)为原料,聚乙二醇为溶剂,NH_3H_2O为沉淀剂,制备纳米氧化铁。然后利用XRD和SEM等分析手段,对样品进行表征,研究结果如下:当pH由6升高到10时,反应时间由90 min可以缩短到30 min,氧化铁的晶体形态从粒状逐渐向片状晶过渡,颜色加深;当反应温度由140℃升高到170℃时,反应时间由90 min缩短到45 min,晶体的平均粒度由50 nm增加到800 nm,均匀性降低,晶体形态由球晶向针状晶过渡,颜色逐渐变红。在本实验条件下,最佳的pH=7,最佳的水热温度为160℃,最佳的水热时间为60 min。

Nano-Fe2O3 was synthesized from FeSO4 by hydrothermal method, using polyethylene glycol as dissolvent and NH3H2O as precipitating agent. It was characterized by XRD and SEM. The results showed that, as increasing of pH value from 6 to 10, reaction time was shortened from 90 min to 30 min, crystal morphology was changed from grainy crystal to flaky crystal, and the color of samples became fuscous. When reaction temperature increased from 140 ℃ to 170 ℃,reaction time was shortened from 90 min to 45 min. The average crystal granularity increased from 50 nm to 800 nm, and crystal uniformity descended. Crystal morphology was changed from spherocrystal to acicular crystal, and the color of samples reddened gradually. On the experimental condition, the optimal pH, hydrothermal temperature and hydrothermal time were 7, 160 ℃ and 60min, respectively.