TiO₂Nanotube Array Prepared by Anodization in Aqueous Electrolyte Containing Sodium Carboxyl Methyl Cellulose

TiO2 nanotubes arrays (TNTAs) were produced on titanium foil by electro oxidation (anodization) based on aqueous electrolyte containing sodium carboxyl methylcellulose (Na-CMC) at various concentration and the applied anodization potential. In aqueous electrolyte, the concentration of Na-CMC showed significant influence in the formation of TiO2 nanotubes. While little effect from the anodization potential was observed. The TNTAs, with very good nanotubes array morphology and photocurrent generation was successfully obtained under aqueous electrolyte containing 0.5% NH4F and 2 % Na-CMC. This obtained TNTAs films has slightly different inner tube diameter when prepared under different anodization voltages, these are 52 4,08, 80 3,48, and 79 4,01 nm respected to 15, 20, 25 V applied potential, respectively. The best photocatalytic activity of TNTAs was observed on the TNTAs film that was prepared under 20 V, whereas this TNTAs film has biggest porosity (41.14 %) and smallest space depletion layer (4.34 nm) compare to other prepared TNTAs film. This result confirms that, narrower of the depletion layer, the separation of the charge on the surface of TNTAs and electrolytes will increase, thus the efficiency of photo conversion increases. Preparation of TNAs by anodization in aqueous electrolyte containing Na-CMC can be an alternative way that meet the environmentally friendly nature, in contrast to those current common way which is using an organic electrolyte.