TiO2 nanotubes as enhanced electrocatalytic oxygen evolution reaction catalyst for water splitting in alkaline medium

Abstract

The literature largely reports titania nanotubes (NTs), a standout component in nanomaterials with exceptional charge transport and carrier lifetime properties. We talked about how to make highly ordered, vertically oriented titanium dioxide (TiO2) nanotube arrays in a one-step potentiostatic anodization of titanium in an ethylene glycol (EG) electrolyte that also has water and sodium fluoride. This study analyzed the effect of anodization voltage on the formation of TiO2 nanotubes. We used field emission scanning electron microscopy (FESEM) and X-ray diffractometer (XRD) to characterize the morphology and structure of TiO2 NTs. Optical studies using UV–Vis diffuse reflectance and photoluminescence spectra also showed that changing the anodization voltage changes the band gap and the way electron-hole pairs recombine. The synthesis of uniform nanotube arrays and their crystal structure led us to the conclusion that 30 V was an ideal anodization potential exclusively for NT formation. The electrocatalytic activity increases as the sample is anodized at 50 V. Due to the crystal defect, this exhibits better oxygen evolution reaction (OER) activity in 1.0 M KOH electrolyte at 1.736 V vs. reversible hydrogen electrode (RHE) at a current density of less than 10 mA cm−2.

Keywords

• Titania nanotubes
• Electrochemical anodization
• Sodium fluoride
• Formation mechanism
• Oxygen evolution reaction