微波快速合成纳米银线及影响因素研究

Fast synthesis and influencing factors of silver nanowires by microwave heating

纳米银线由于具有优良的电学及光学性能而受到广泛关注。采用微波辅助加热技术,成功制备了高长径比的纳米银线,采用XRD、SEM研究了产物的物相组成及形貌,用紫外-可见光分光光度法测试不同条件下制备的纳米银的吸收光谱,详细探讨了反应因素对生成的纳米银线的影响。研究表明:纳米银线的最佳制备条件为微波功率300 W,硝酸银与PVP质量比1:2.5,氯化钠浓度2.5 mmol/L,反应时间4 min,反应温度190℃,产物为纯的纳米银线,直径约40 nm,长度约15μm。较之传统水热法,本方案仅需4 min就制备出高长径比纳米银线,优势明显。

Silver nanowires have got much attention due to their excellent electrical and optical properties. A microwave-assisted heating method was introduced to synthesize silver nanowires with high aspect ratio. Then the composition, morphology and absorption spectrum of the products prepared under different conditions were characterized by XRD, SEM and UV-Vis, and different factors on the formation of silver nanowires were discussed. Results show that： the final products are pure silver nanowires with diameter about 40 nm and length about 15 0m with the best preparation process （microwave power is 300 W; mass ratio of AgNO3 to PVP is 1：2.5; concentration of NaCl is 2.5 mmol/L, reaction time is 4min; reaction temperature is 190 ℃）. Compared with traditional hydrothermal method, this method could prepare silver nanowires with high aspect ratio in less than 4 min, showing significant advantage.