温和条件下钴酸镍的水热合成

Hydrothermal synthesis of nickel cobaltate under milder condition

利用镍、钴的醋酸盐为原料在温和条件下成功地用水热法合成了纯的尖晶石型钴酸镍。用XRD、SEM、TEM、IR对产物进行了表征,并对体系的酸碱性、矿化剂、原料配比、反应温度和反应时间等影响因素进行了研究。矿化剂氨水浓度大于4 mol/L或小于1.5 mol/L,钴、镍的醋酸盐物质的量比大于7∶3或小于2∶1,水热合成温度小于220℃,合成时间小于72 h均无法得到纯的钴酸镍。当钴、镍的醋酸盐物质的量比控制在7∶3,加入2.5 mol/L氨水,在220℃水热反应72 h可以得到纯的纳米级钴酸镍,并用醋酸洗去少量残存的氧化镍杂质。

Pure spinel-type nickel cobaltate （ NiCo2O4 ） was sucessfully prepared by hydrothermal synthesis method under milder reaction conditions with nickel acetate and cobalt acetate as raw materials. Product was characterized by XRD, SEM, TEM, and IR. Influencing factors, such as acid - base property, mineralizers, raw material mix ratio, time, and temperature, of the reaction system were invesitgated. When the concentration of mineralizer NH3 · H2O was more than 4 mol/L or less than 1.5 mol/L,amount-of-substance ratio of cobalt acetate to nickel acetate was higher than 7：3 or lower than 2：1 ,hydrothermal synthesis temperature was below 220 ℃and synthesis time was less than 72 h, no pure NiCo2O4 will be obtained. On the other hand,under the conditions that amount-of-substance ratio of Co to Ni was 7： 3, c （ NH3 · H2O ） = 2.5 mol/L, hydrothermal reacting at 220℃ for 72 h, pure NiCo2O4 nano-particles could be obtained after using acetic acid to wash a small amount of nickel oxide impurity.