硝酸银溶液中Zn置换微细Ag粒子的激光辐照银制备法

Silver Preparation Through Ultrafine Ag Particles Displaced by Zn in Silver Nitrate Solution with Pulsed Laser Radiation

研究脉冲激光辐照对锌粉置换硝酸银溶液制备银的影响,并用激光辅助合成微细银粒子·添加了激光能量后,激光束能打碎Ag包裹Zn形成的复合粒子,进一步促进置换反应的进行·同时脉冲激光作为热源,可以促使AgNO3发生光热分解反应,产生微小的银粒子,从而提高了Ag的析出率·制备的产物用SEM及能量散射谱仪EDS分析鉴别·由SEM图及能量散射谱EDS图可以看出,经激光辐照与未经激光辐照而制备的两种银粒子的形貌并不相同,添加激光能量后制备的银粒子优于未添加激光制备的银粒子·

The effect of pulsed laser radiation on the preparation of silver was experimentally studied, of which the ultrafine Ag particles in AgNO_3 solution were displaced by Zn powder, with the preparation mechanism analyzed. The laser beam energy was proved to be able to break up the clad particles which the larger Zn particles were wrapped up by Ag, thus expediting the displacement reaction. At the same time, the pulsed laser energy as a heat source will spur AgNO_3 to decompose photothermically to precipitate ultrafine Ag particles. In this way the rate of precipitation of Ag rises. The Ag particles precipitated with and without pulsed laser radiation were compared with each other and analyzed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results revealed that both the morphology and size of the two ultrafine Ag particles are different,and those with laser radiation are better than those without laser radiation in either grain size or purity.