密度梯度离心分离法研究银纳米片边缘晶面的反应活性

Use of density gradient ultracentrifugation separation to provide evidence of the size-dependent reactivity of silver nanoplates

利用密度梯度法对纳米银片进行离心分离,在分离过程中使用巯基乙醇对银片进行轻度刻蚀。用透射电镜、紫外可见分光光度计对分离后的各层样品进行表征,结果表明:不同尺寸的银纳米片的边缘具有不同的反应活性,不同晶面的晶区大小同样影响银纳米片的反应活性;在银片边长为(135±5)nm时存在一个尺寸阈值,低于此尺寸阈值,银片(110)晶面的反应活性高于(100)晶面的活性,而高于此尺寸阈值,(100)晶面的活性高于(110)晶面的活性。

By employing density gradient ultracentrifugation separation, we have developed a mild etching method for silver nanoplates, in which mercaptoethanol serves as the etchant. It was found that there is a critical crystal lat- eral size of around 135 nm. If the lateral size is below this value, the （110） lattice planes are more reactive, while above this critical size, the （100） lattice planes become more reactive.