Surface Metal Ion Doped Tio2 Nanowire Arrays by Low Energy Ion Implantation for Enhanced Photoelectrochemical Water Splitting

Abstract

Various metal ions, including Mg, Co, Nb, W, were chosen for ion implantation to modify TiO2 nanowire arrays. The introduction of metal ions was confirmed by both simulations and transmission electron microscopy (TEM) morphology characterization. The ion implantation process resulted in a doped TiO2 shell on the surface. Furthermore, W ions separated out and formed the metal composition. The XPS results implied a special mechanism of heavy ions chosen for low energy ion implantation. It was proved that the presence of non-bonded metal restricted water splitting ability evidently. PEC results provided brief evidence that Nb doped TiO2 nanowire arrays is a promising choice with 60% improvement in current density. The charge transfer resistance and the flat band potential are more benefit to water splitting than other ions, which was also supported by the theoretical calculation.

Keywords: Ion implantation, TiO2 NWAs, Water Splitting