TiO2 nanorods grown by hydrothermal method and their photocatalytic activity for hydrogen production

• Published in: Materials letters 2019-02, Vol.237, p.310-313
• Main Authors: Alfaro Cruz, M.R., Sanchez-Martinez, D., Torres-Martínez, L.M.
• Format: Article
• Language: English
• Subjects: Hydrogen production; Photocatalysis; Thin films; TiO2
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2018.11.040

•TiO2 thin films were grown by sputtering method and use as seed layer to grow TiO2 nanorods by means of hydrothermal method.•TiO2 nanorods has 3.5 higher activity (132 μmol) than TiO2 seed layer (38 μmol).•TiO2 nanorods has the contribution of Ti3+ species, which reduce the band gap value and improve the photocatalytic activity. TiO2 nanorods were prepared by hydrothermal method over TiO2 seed layers deposited by DC Sputtering. From the XRD structural characterization, it has been stated that TiO2 seed layer present mainly the anatase phase with some contributions of rutile phase, while for TiO2 nanorods, the rutile phase is present. The thin film thickness were measured using a profilometer, resulting in a thickness of 310 nm for the seed layer and ∼400 nm for TiO2 nanorods. PL analysis for both films presented an indirect transitions Γ1b → Χ2a, as well as oxygen vacancies, defects and surface states. Photocatalytic H2 production for TiO2 seed layer film was around 38 μmol, while TiO2 nanorods produced 132 μmol. This is attributed to the increase to the midgap states present below the conduction band and near to the valence band, which help to improve the photocatalytic activity.