Enhanced photoelectrochemical and photocatalytic performance of single-crystalline anatase TiO2 (1 0 1) nanobelts arrays originating from nanotubes arrays

TiO2 photocatalysts with high photocatalytic activity are potentially applied to degrade pollutants, split water and transform solar energy. Herein, TiO2 nanobelts (TiO2 NB) arrays originating from nanotubes arrays were successfully prepared via simple anodization. The surface morphology, structure, elemental composition, photoluminescence spectra (PL), photoelectrochemical (PEC) properties and photocatalytic activity of the resulting samples were investigated. The results show that as-prepared TiO2 NB arrays exhibited significant enhancement in separation efficiency of photogenerated electrons (e−) and holes (h+) pairs and then in photocatalytic activity under simulative solar irradiation compared with TiO2 nanotubes (TiO2 NT) arrays, which could be attributed to the following aspects: (i) specific belt-like morphology leads to higher accessibility of TiO2 NB arrays for reactants and more active sites on the surface of TiO2 NB; (ii) single-crystalline anatase phase structure gives rise to faster electron mobility and less electron-trapping sites in the bulk; and (iii) exposed crystal face (1 0 1) yields an enhanced reactivity with molecular O2, facilitating the trapping of photogenerated electrons and generation of superoxide radical. Otherwise, this TiO2 NB arrays overcome the deficiency of filtering separation from water and exhibit excellent photocatalytic stability, thus it is promising to be applied in pollutants elimination and photocatalytic decomposition of water.