柠檬酸盐凝胶法制备纳米氧化镍的研究

优化了柠檬酸盐凝胶法制备纳米氧化镍粉体的工艺条件.采用傅立叶红外光谱(FTIR)、热分析(TG/DTA)、X射线衍射(XRD)、扫描电镜(SEM)和BET法对柠檬酸镍络合物的形成,凝胶热分解过程,产物的形貌、粒径和比表面积大小以及同材料配比、热处理温度、热处理时间之间的关系进行了研究,确定了制备纳米氧化镍的最佳工艺条件(柠檬酸与镍离子摩尔比1.2:1.0,400℃热处理1h),并在此条件下成功制备了粒径达30nm,比表面积达181.29m²/g的NiO粉体.通过热力学计算,解释了在凝胶热分解过程中金属镍相出现的可能原因.

Preparation of Nanometer Nickel Oxide by The Citrate-Gel Process

The optimum process for preparing nanometer nickel oxide by the citrate-gel method was studied. The gel and products derived from the consequent thermal decomposition were characterized by FTIR, XRD, SEM and BET techniques.The thermal decomposition of the gel was analysed by TG/DTA. The effects of heat-treatment temperature, time on particle shape, size and specific surface area were studied and the preparation process was optimized. The NiO prepared in the optimum conditions (CA: Ni²⁺ mole ratio 1.2:1.0, 400℃ heat-treatment for 1h) has particle size <50nm, specific surface area >180m²/g. The metallic nickel formation during the gel heat treatment is due to the in situ reduction of nickel oxide by carbon or carbon monoxide produced from the gel precursor.