Au nanoparticles decorated titanium dioxide nanotube arrays with enhanced photocatalytic dye degradation under ultraviolet and sunlight irradiation

Abstract

The aim of this study is to show that the geometry of titanium dioxide (TiO sub(2)) nanotubes has an inevitable role in photocatalytic activity. The TiO sub(2) nanotubes were synthesized by anodization technique. Au nanoparticles (AuNPs) were spin-coated onto the surface of these nanotubes. The photocatalytic activity study was conducted using methylene blue dye under UV light and sunlight. In contrast to the obtained results under UV light irradiation, the photocatalytic activity under sunlight irradiation of AuNPs-coated TiO sub(2) nanotubes was much higher. The nanotubes showcased improved visible light absorption and photocatalysis under sunlight condition due to the SPR effect of AuNPs. Compared to other samples, the nanotubes prepared at 600 s (second) duration had an intrinsic geometry which exhibited high photocatalytic activity under sunlight irradiation. These results indicate that the maximum photocatalytic efficiency of TiO sub(2) nanotubes can be achieved by carefully designing the nanotube geometry.