pH值对微波水热法制备纳米α-Fe_2O_3的控制作用

Effect of pH Value on Preparation of Nanon α-Fe_2O_3by Microwave Hydrothermal Method

系统地研究了以Fe(NO3)3为原料,反应液的初始pH值对微波水热法制备纳米α Fe2O3粒子形貌的控制作用。实验结果显示:当pH=1时,所得产物为纺锤形具有较大比表面积的多孔结构;当pH=3时,为近球形的多孔结构;当pH=5时,为菱形单晶且无孔、无团聚;当pH=7时,在相同的反应条件下仍为非晶Fe(OH)3,并未转化为α Fe2O3。同时还分析了pH值及反应液中存在的无机小离子对α Fe2O3生成速率的影响。

Effect of initial pH values on preparation of nanon αFe2O3 particles using Fe(NO3)3 as starting material by microwave hydrothermal method was systematically studied.Experimental results showed that when pH=1,the product was spindleshaped with high specific surface area and porous structure;when pH=3,the product had spheric shape with porous structure;when pH=5,the product was rhombohedral single crystal,nonporous and nonaggregated;but when pH=7,under the same reaction conditions,the product was amorphous Fe(OH)3 and didn't convert to αFe2O3.Effects of pH value and small inorganic ions in solution on the formation rate of αFe2O3 were also studied.