Abstract Herein, the anodization of 2.6 μm Al-0.2 at.% Cu (Al-0.2 Cu) films on TiN/p-type Si substrate were performed using common acidic mediums at different ranges of anodization voltage (V a) to produce porous anodic alumina (PAA) nanostructures with high porosity. The anodization of Al-0.2 Cu in 1 M H 2 SO 4 at V a range of 10–30 V produced a higher oxide thickness, and hence, a higher volume expansion factor, compared to the anodization in 0.75 M H 3 PO 4 at V a range of 100–140 V. The increase in V a, as expected, increases the inter-pore distance, pore size, and porosity of the PAA and improves the anodization rate. The optical sensing performance of the synthesized PAA under different conditions was investigated. The maximum surface wettability was attained for PAA anodized in 1 M H 2 SO 4 at 20 and 30 V. Moreover, the Vickers hardness (HV) of PAA was improved by forming a thin alumina …