TiO₂ Nanotubes Decorated with Mo₂C for Enhanced Photoelectrochemical Water-Splitting Properties

The presence of Ti³⁺ in the structure of TiO₂ nanotube arrays (NTs) has been shown to enhance the photoelectrochemical (PEC) water-splitting performance of these NTs, leading to improved results compared to pristine anatase TiO₂ NTs. To further improve the properties related to PEC performance, we successfully produced TiO₂ NTs using a two-step electrochemical anodization technique, followed by annealing at a temperature of 450 °C. Subsequently, Mo₂C was decorated onto the NTs by dip coating them with precursors at varying concentrations and times. The presence of anatase TiO₂ and Ti₃O₅ phases within the TiO₂ NTs was confirmed through X-ray diffraction (XRD) analysis. The TiO₂ NTs that were decorated with Mo₂C demonstrated a photocurrent density of approximately 1.4 mA cm^-2, a value that is approximately five times greater than the photocurrent density exhibited by the bare TiO₂ NTs, which was approximately 0.21 mA cm^-2. The observed increase in photocurrent density can be ascribed to the incorporation of Mo₂C as a cocatalyst, which significantly enhances the photocatalytic characteristics of the TiO₂ NTs. The successful deposition of Mo₂C onto the TiO₂ NTs was further corroborated by the characterization techniques utilized. The utilization of field emission scanning electron microscopy (FESEM) allowed for the observation of Mo₂C particles on the surface of TiO₂ NTs. To validate the composition and optical characteristics of the decorated NTs, X-ray photoelectron spectroscopy (XPS) and UV absorbance analysis were performed. This study introduces a potentially effective method for developing efficient photoelectrodes based on TiO₂ for environmentally sustainable hydrogen production through the use of photoelectrochemical water-splitting devices. The utilization of Mo₂C as a cocatalyst on TiO₂ NTs presents opportunities for the advancement of effective and environmentally friendly photoelectrochemical (PEC) systems.