利用钠-氨溶液制备纳米金属镍粉末及其表征

Preparation and characterization of nanoscale nickel metal powder through sodium-ammonia solution

利用两步法制备得到纳米金属镍粉末。首先以氯化镍为原料在钠-氨溶液内通过还原-氮化反应制备得到纳米氮化镍粉末,然后通过真空热分解成功制备出纳米尺度的金属镍粉末。研究表明:钠-氨溶液内制备得到的纳米氮化镍粉末为六方结构,其平均晶粒尺度为19 nm;在300℃条件下进行真空热处理后,纳米氮化镍粉末完全分解,获得立方结构的纳米金属镍粉末,其平均晶粒尺度为21.4 nm,比表面积为30.5 m2·g-1;在300~700℃真空热处理过程中,纳米金属镍粉末的平均晶粒尺度增大为36.8 nm,比表面积减小为13.2 m2·g-1。

Nanoscale nickel metal powder was prepared by a two-step process. In the first step,nanoscale nickel nitride powder was prepared via reduction and nitridation of nickel chloride in sodium-ammonia solution. In the second step,nanoscale nickel metal powder was successfully obtained through the vacuum thermal decomposition of the nanoscale nickel nitride powder. The experimental results show that the nanoscale nickel nitride powder obtained from sodium-ammonia solution exhibites hexagonal crystal structure and average crystalline size of 19 nm. Furthermore,after vacuum heat treatment at 300 ℃,the nanoscale nickel nitride powder is completely decomposed,then the nanoscale nickel metal powder is produced,with cubic crystal structure,average crystalline size of 21. 4 nm,and specific surface area of 30. 5 m2·g- 1. During vacuum heat treatment of the nanoscale nickel metal powder at 300-700 ℃,its average crystalline size gradually increases to 36. 8 nm,and its specific surface area gradually decreases to 13. 2 m2·g- 1.