溶胶-凝胶自蔓延法制备球形纳米铜粉

Sol-Gel Self-propagating Synthesis of Copper Nano-particles

以硝酸铜、柠檬酸为原料,利用氨水调节pH制备溶胶,将溶胶蒸发干燥得到的干凝胶通过自蔓延法制得金属铜纳米粉体,研究pH在制备溶胶-凝胶过程中对成胶时间的影响,以及pH、自蔓延温度对产物组成的影响;通过差热分析、X射线衍射和扫描电镜分别对凝胶的热分解机制、产物的物相组成以及形貌和粒度进行分析。结果表明,当pH=6～7时,形成的凝胶均一,凝胶时间最短(4 h);当自蔓延反应温度为250℃时,可以制得粒径为50～70 nm的球形纳米铜颗粒。

Copper nano-particles were obtained by using sol-gel selfpropagating process,in which copper nitrate and citric acid were used as raw materials,and ammonia was used to control pH.Weightlessness and thermal decomposition temperature of the dry gel were analyzed by TG-DTA.The phase and morphology of products were characterized by XRD and SEM.The results show that pH has great effect on the gel times and consists of final products.The obtained gel is uniform and the gel-time is the shortest（4 h） when pH =6～7.The reaction temperature of auto-combustion can influence the size and morphology of copper nano-particles.When the reaction temperature is 250 ℃,the obtained products are display sphere-like morphology with approximate diameters of 50～70 nm.