Anodization of Zirconia Nanotubes for Lead (II) Adsorption

Zirconia (ZrO2) nanotubes were prepared by anodization of zirconium (Zr) foil in a glycerol-formamide electrolyte containing ammonium fluoride. The effects of anodizing voltage and temperature on the pore diameter and thickness of the resulting nanotube array were studied. ZrO2 nanotubes with larger pore diameter were formed at higher anodizing voltage and temperature. Additinally, the thickness of the oxide layer was also increased. The applicability of the ZrO2 nanotubes for adsorption of heavy metals in aqueous solution was evaluated using Pb (II) as the model ions. Generally, the uptake of Pb (II) was increased at longer adsorption time and higher initial concentration of the adsorbate.