Time Resolved Study on Fabrication of Porous Alumina for Further Use to Generate Metallic Nano Catalyst

Porous anodic alumina (PAA) is one of the important nanostructured materials. This has gained exposure recently for applications in gas separation[1], drug delivery[2], bone fixation [3] and as a template for formation of nanostructures [4]. Anodic porous alumina is formed by the anodization of Aluminum, which is a self-organized material, to get a layer of nanoporous oxide [5]. This porous anodic aluminum (PAA) membrane consists of a ordered hexagonal arrangement of cells with a central pore per cell that elongates from top to bottom of the layer, resembling a honeycomb [6]. These pores are used as template for synthesis of 1dimensional (1D) nanostructure and hence the degree of ordering of these cell arrangements plays an important role in the homogeneity of the resulting nanomaterials.

            Present work focuses on study of anodization as function of time, to see the trend in pore size, pore density and degree of ordering of Anodized Aluminum oxide (PAA) membrane. Proper selection of anodization time and phases allow the tuning of self-ordering regime, control of local catastrophic phenomena and achievement of a more uniform growth. Afterward, self-assembled template has been used for the synthesis of novel ID nanostructure of tungsten trioxide by electroless deposition method. Scanning Electron Microscope (SEM) images depict uniform arrangment of tungsten trioxide nanowire. Internal diameter of formed nanowires is around 50 nm similar to porous diameter of PAA templates. Furthermore XRD patterns of nanowire indicate the presence of two crystalline forms of WO₃ i.e. monoclinic and orthorhombic.

References

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