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 SrTiO3-TiO2 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 SrTiO3-TiO2 nanotubes. The characterization analysis results indicated that because of the increased conversion of H2Ti6O13 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 H2Ti6O13 nanotubes, (2) an improvement in the perovskite SrTiO3 and anatase TiO2 conversion, and (3) the uniform dispersion of SrTiO3 square particles. Due to the improved contact between the SrTiO3 particles and the anatase TiO2 nanotube, the electronic transport, charge separation, and solar light-response were increased. Based on the excellent charge separation and solar light-response of SrTiO3-TiO2 nanotube, the H2 evolution activity of N-TiO2/SrTiO3-TiO2 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-TiO2/SrTiO3-TiO2 nanotube reached 3873 µmol/h/g under sunlight irradiation.