葡萄籽纳米银的制备及其在染料催化还原降解中的应用

Preparation of silver nanoparticles using grape seed extract and its application to reductive degradation of dyes

选用葡萄籽提取物作为还原剂和稳定剂,采用生物还原法制备葡萄籽纳米银粒子,讨论了反应条件对葡萄籽纳米银制备的影响。试验结果表明,葡萄籽提取物溶液在可见光范围内无明显吸收峰,而葡萄籽纳米银粒子溶液在422 nm处存在明显的吸收峰。激光粒径仪分析可知,葡萄籽纳米银粒子的最小平均粒径可达22 nm左右;TEM图显示,葡萄籽纳米银粒子外观形态基本呈现圆球状,分散比较均匀。同时,葡萄籽纳米银粒子可对染料直接红23进行催化还原降解,不同p H值条件下制备的葡萄籽纳米银粒子在催化性能方面存在一定的差异。较高pH值条件下(pH=8.0)制备的纳米银粒子,由于其平均粒径更小且产率更高,催化效率更高。反应12 min,直接红23染料的催化降解率可达94%以上。

In order to develop the green synthesis of silver nanoparticles （AgNPs）, grape seed extract is selected as reducing and stabilizing agent for biosynthesis of AgNPs, and the effects of reaction conditions on preparation of AgNPs are discussed. The results show that the grapes seed extract solution has no obvious absorption peak in the range of visible light, while the prepared AgNPs show an intense peak at 422 nm. The minimum average particle size of the prepared AgNPs is found to be around 22 nm by the analysis of Laser Particle Size Analyzer. The appearances of the prepared AgNPs are found to be substantially spherical with good dispersion uniformity which can be seen in the TEM images. Meanwhile, the prepared AgNPs show the ability for the catalytic degradation for Direct Red 23, and there is a difference of the catalytic ability for the AgNPs synthesized at different pH values. The AgNPs synthesized at relative high pH value （pH=8.0） show the highest catalytic capacity respecting to the smallest particle size distribution and highest production, and more than 94% Direct Red 23 dye has been degrad- ed with 12 min.