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

Abstract

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