简单蚀刻法制备具有可控高度的金属纳米线阵列

Preparation of metal nanowire arrays with controllable length using a simple etching method

采用多孔阳极氧化铝(AAO)作为模板,运用电化学沉积法在模板的微孔中组装金属N i纳米线,然后用磷铬酸蚀刻表层AAO模板,暴露出规整有序、具有可控长度的N i纳米线阵列。分别用SEM、TEM与SAED对N i纳米线阵列进行了表征。研究了蚀刻时间与AAO模板质量的减少及暴露出来的N i纳米线阵列长度之间的关系。结果表明,磷铬酸是较NaOH溶液更为温和有效的AAO模板蚀刻剂,通过控制模板溶解时间,可以实现对裸露于AAO模板外纳米线长度的精细有效控制。该蚀刻方法普遍适用于以AAO为模板所制得的准一维纳米阵列结构。

Ni nanowires are prepared by electrodepositing Ni into porous anodized aluminum oxide （AAO） template with nanosized pores. And then well ordered Ni nanowire arrays with controllable length are made from partial removal of AAO in mixture of phosphoric acid and chromic acid （6 wt% H3PO4： 1.8 wt% H3CrO4 ）. The images of Ni nanowire arrays are obtained by scanning electron microscope （SEM） and transmission electron microscope （TEM）, respectively. Selected area electron diffraction （SAED） are employed to study the crystalline morphology of Ni nanowire arrays. Also, the relations be- tween the etching time and the mass reduction of AAO template, the length of Ni nanowire arrays are dis- cussed. The results indicate that mixture of phosphoric acid and chromic acid is a more mild and effective etchant compared with NaOH aqueous solution. When using mixture of phosphoric acid and chromic acid as etchant, the length of nanowires exposed from template can be accurately controlled through controlling etching time. This etching method is generally applicable for many one - dimensional nanoarrays prepared from AAO template -assisted synthesis.