Investigation of homogeneous large surface area anodic alumina membrane synthesis

This work is concerned with the large scale synthesis of anodized aluminum oxide membrane (AAO) and thus mass production of 1D nanoparticles. Firstly, a high purity of aluminum foil with a surface area of 10 cm² was annealed, degreased, etched, and electropolished. The foil was then anodized using a vertical set-up, in oxalic acid at 40 V, to form a porous membrane with homogeneous hexagonal pattern. The barrier layer was thinned and eventually removed by applying voltage step down and phosphoric acid etching. The SEM and XRD results show that pore sizes are homogeneously distributed. The cross sectional view of the membrane shows that the barrier layer has been eliminated completely, which paves the way for downstream synthesis of one-dimensional nanostructures by electrodeposition into pores, using the aluminium at the pore base as an electrode.