用低纯度铝制备AAO模板及其结构研究

在0.3mol/dm3草酸溶液中,通过不同纯度铝的恒电位二次阳极氧化制备了纳米孔氧化铝模板,并用场发射扫描电子显微镜(FE-SEM)和原子力显微镜(AFM)观察模板结构.实验结果表明,一次氧化除膜后低纯度铝基体表面呈现较为规则的六边形结构,这种蜂巢结构有利于二次氧化过程中获得有序度更高的纳米孔模板.低纯度铝制备的模板表面被晶界分隔为微小的区域,只是在较窄区域内才出现六边形规则排列的纳米孔.恒电位40V时所得模板经扩孔处理后,孔径由35nm增大到100nm左右,且孔径大小几乎一致.从纳米孔的有序度来看,由低纯度铝制备模板还需要进一步优化阳极氧化参数.

Structural Properties of AAO Template Fabricated by Low-purity Aluminum

The anodic aluminum oxide(AAO) template with nanopore arrays was fabricated on aluminum foils of different purities.These experiments were carried out in 0.3mol/dm~3 oxalic acid using two-step anodization method under constant voltage.Field emission scanning electron microscopy(FE-SEM) and atom force microscopy (AFM) were used to observe the microstructure of the AAO template.The results showed that regular hexagonal nanopores were arranged on the aluminum substrate after one-step anodization,and these honeycomb structures make for more orderly nanopore structures during the second anodization.The nanopore arrays of the template from low-purity aluminum were only present on the relatively narrow region separated by the cell boundary.The template prepared at constant voltage of 40V exposited uniform pores and pore diameter varied from 35nm to 100nm after etching in phosphoric acid.Therefore,if need be,the best condition to fabricate porous anodic aluminum oxide template using low-purity aluminum can be easily selected.