Excellent dispersion and charge separation of SrTiO3-TiO2 nanotube derived from a two-step hydrothermal process for facilitating hydrogen evolution under sunlight irradiation

Abstract A new, facile, and effective two-step hydrothermal process was developed for the formation of SrTiO 3 -TiO 2 nanotube with excellent charge separation, electronic transport, and sunlight response successfully. There are evidences that adjusting the hydrothermal temperature of H-titanate was an effective method of preparing versatile SrTiO 3 -TiO 2 nanotubes. The characterization analysis results indicated that because of the increased conversion of H 2 Ti 6 O 13 nanotube at 150 °C, the nanotube could provide abundant sites for Sr ions adsorption, resulting in (1) the increased probability of a reaction occurring between the Sr ions and the H 2 Ti 6 O 13 nanotubes, (2) an improvement in the perovskite SrTiO 3 and anatase TiO 2 conversion, and (3) the uniform dispersion of SrTiO 3 square particles. Due to the improved contact between the SrTiO 3 particles and the anatase TiO 2 nanotube, the electronic transport, charge separation, and solar light-response were increased. Based on the excellent charge separation and solar light-response of SrTiO 3 -TiO 2 nanotube, the H 2 evolution activity of N-TiO 2 /SrTiO 3 -TiO 2 nanotube could be remarkably enhanced by modifying the surface with small amount (0.2 wt%) of Pt, and the hydrogen evolution rate of Pt/N-TiO 2 /SrTiO 3 -TiO 2 nanotube reached 3873 µmol/h/g under sunlight irradiation.