Anodized Titanium with Aqueous Based Electrolyte for Waste Water Treatment
Titanium dioxide nanotubes on titanium surface were prepared by electrolytic anodization in aqueous solution at constant voltages at room temperature for 2, 4 and 6 hours. Anodized titanium was heat treated in a furnace at 450 °C for 4 hours to convert amorphous structure to anatase and rutile crystalline structure. A scanning electron microscope was utilized for morphology investigation of the anodized titanium surfaces. For HF containing water media, porous surface on titanium was revealed after anodizing for 2 hours. Nanotubes (NT) were formed in this media at 4 and 6 hours anodizing time, the diameters of the tubes were approximately 70 to 100 nm. For HF/Na2SO4 aqueous solution, fine NTs, approximately 50 nm in diameter, were grown after 2 hours. However, the NTs obtained at anodizing time 4 and 6 hours were the same size, ranging from 100 to 120 nm. Anatase and rutile phases of TiO2 were formed in the anodized samples after annealing at 450 °C for 4 hours. The anodized samples were tested for their abilities to degrade Rhodamine B, to demonstrate their application as a material for waste water treatment. The Rhodamine B was degraded up to 41% in annealed sample anodized by electrolyte contained HF.