Anodic TiO₂ nanotube arrays as fixed photocatalyst

In the present study, self-organized TiO₂ nanotube arrays were prepared by anodic oxidation in a viscous electrolyte of ethylene glycol containing NH₄F with a concentration of 1.25% wt. The anodized samples exposes single walled nanotube arrays with an average pore diameter and wall thickness of about 80 and 15 nm, respectively. The photocatalytic efficiency of the nanotube arrays has been investigated and compared to commercial P25 nanopowder by measuring the degradation of methyl orange. The results showed that the nanotube arrays exhibit higher activity towards dye degradation as compared to commercial P25 nanoparticles with a degradation efficiency reaching up to 99.45% after an irradiation time of 60 min. The high surface to volume ratio and the mechanical adhesion makes them suitable as multiple use photocatalysts.