Lanthanum Hydroxide Clusters Implanted TiO₂ Nanotube Arrays for Enhanced Photoelectrochemical Water Splitting

Abstract

We report the fabrication of a titania nanotube (TNT) and lanthanum hydroxide [La(OH)3] cluster (LHC) nanocomposite. The composite material prepared is characterized and tested for a photoelectrochemical water-splitting reaction. TNTs prepared from an organic medium are embedded with LHCs (synthesized from the microemulsion process) by the dip-coating method and annealed at 600 °C for 2 h in an ambient atmosphere to form the nanocomposite. The electronic properties of the composite material are characterized by potentiodynamic electrochemical impedance spectroscopy (PEIS and Mott–Schottky). The effect of composite formation that resulted in enhanced photoelectrochemical properties is defined by surface photovoltage. It is found that the nanocomposite shows enhanced activity for the water-splitting reaction under illuminated conditions. It exhibits a photocurrent density of ∼1 mA cm–2, which is 9 times greater than that of pure titania nanotubes. It is evident from the experimental results that the increased photocurrent generated is primarily due to the better charge carrier separation in the composite material.