石榴皮纳米银的制备及其对有机染料的催化降解

Preparation of pomegranate rind nanosilver and its catalytic degradation of organic dyes

以硝酸银为前驱体,石榴皮提取液为还原剂和稳定剂,生物法制备纳米银颗粒AgNPs,探讨了提取液pH、石榴皮提取液质量浓度、硝酸银浓度、反应时间和反应温度对AgNPs性能的影响。采用紫外可见吸收光谱、傅里叶变换红外光谱、X射线衍射和透射电镜等测试手段对AgNPs结构及性能进行表征。并以AgNPs为催化剂,NaBH(Ac)3为还原剂,酸性橙7、酸性红13、直接黄44和直接蓝15为有机染料目标降解产物,探究了AgNPs催化性能。结果表明:Ag-NPs颗粒近似为球形,晶型为面心立方晶体,平均粒径为(14.7±0.37)nm,特征吸收峰在420 nm附近。NaBH(Ac)3中添加AgNPs后,15 min内对酸性橙7、酸性红13、直接黄44和直接蓝15的降解率分别达到了94.34%、93.54%、97.7%和90.15%;并推测了AgNPs催化降解染料的机理。

Silver nanoparticles(AgNPs)are bioprepared by using silver nitrate as precursor and pomegranate rind extract as reducing agent and stabilizer,and the effects of pH of the extract,pomegranate rind extract con⁃centration,silver nitrate concentration,reaction time and reaction temperature on the properties of AgNPs are investigated.The structure and properties of AgNPs are characterized by UV-vis absorption spectroscopy,Fou⁃rier transform infrared spectroscopy,X-ray diffraction and transmission electron microscopy.The catalytic per⁃formance of AgNPs is investigated by using AgNPs as catalyst,NaBH(Ac)3 as reducing agent,and Acid Orange 7,Acid Red 13,Direct Yellow 44,and Direct Blue 15 as degradation products of organic dyes.The results show that AgNPs particles are approximately spherical,with a face centered cubic crystal structure and an average particle size of(14.7±0.37)nm.The characteristic absorption peak is around 420 nm.After adding AgNPs to NaBH(Ac)3,the degradation rates of Acid Orange 7,Acid Red 13,Direct Yellow 44,and Direct Blue 15 within 15 min reach 94.34%,93.54%,97.7%,and 90.15%,respectively.The mechanism of catalytic degradation of dyes by AgNPs is speculated.