摘要：以硝酸铜、柠檬酸和氨水为原料, 利用柠檬酸溶胶-凝胶法制备含铜凝胶, 在氮气气氛下将干凝胶煅烧得到纳米铜粉, 探讨成胶反应温度、原料配比、pH等因素对制备过程的影响, 确定最低煅烧温度;采用热重-差热分析和红外光谱分析对柠檬酸溶胶-凝胶法制备纳米铜粉的过程进行分析, 利用X射线衍射和扫描电镜对实验产物进行结构、形貌表征。结果表明, 将柠檬酸与硝酸铜的物质的量比控制为1∶2时溶解混合, 调节pH为7, 在80℃下制成凝胶, 在100℃下干燥后, 250℃下煅烧0.5 h, 可制得粒径为7090 nm的球型铜粉;推断干凝胶的结构主要为柠檬酸根与铜离子以双齿配位, 以及部分为桥式配位。

关键词：溶胶-凝胶法；纳米铜；柠檬酸

Abstract：Copper nano-particles were synthesized using sol-gel method with copper nitrate, citric acid and ammonia as starting materials. Experimental study of the effects of reaction temperatures, ratios of raw materials and pH values were carried out. TG-DTA was applied to analyze the minimum calcinations temperature of the dry gel. The structure and morphology of the nano-particles were characterized by XRD and SEM. The results show that the optimal conditions are as follows: molar ratio of citric acid and copper nitrate is 1∶2, pH value is 7, reaction temperature is 80 ℃, drying temperature is 100 ℃ and calcining temperature is 250 ℃ for 0.5 h. Ball-like copper nano-particles of 70 to 90 nm can be obtained under the above conditions. The structure of dried gel is deduced that citrate acid and copper ion exist mainly in two-tooth complex and partly in bridge complex.

Keywords：sol-gel process; copper nano-particles; citrate acid