Anodic TiO₂ nanotubes for hydrophobic coatings and photo-electrochemical water splitting application

Abstract

In recent years, anodic TiO2 nanotubes (TNTs) have been considered as one of the most promising material in the field of photoelectrochemical water splitting, hydrophobic coatings, solar cells etc owing to their outstanding properties such as unidirectional charge transfer, high surface to volume ratio along with the non-toxicity, corrosion resistance, high thermal and chemical stabilities. In the present study, TNTs were successfully fabricated using a simple and low cost electrochemical anodization technique at 30 V and 60 V. The morphological and structural information of the TiO2 nanotube arrays were investigated through SEM and XRD analysis. This analysis revealed that fabricated nanotubes were having a set of length and pores diameters (2.5 µm, 70 nm), (17 µm, 120 nm) respectively for 30 V TNT and 60 V TNT samples. Electronic band gap and surface functional groups of TNTs were examined by diffuse reflectance and attenuation total reflection spectroscopy studies. This analysis divulged that fabricated sample surface was free from chemicals and energy band gap found to be around 3.2 eV. The contact angle measurement revealed that as-fabricated 30 V TNT sample has shown an enhanced hydrophobic nature (135.90) and whereas annealed 60 V TNT sample has shown an enhancement in the photocurrentdesnity (70.7 µA.cm-2). These findings show that fabricated TNTs can be used in hydrophobic coatings along with photocatalytic applications.