A new-type of semiconductor Na0.9Mg0.45Ti3.55O8: preparation, characterization and photocatalysis

Abstract

A new-type of semiconductor photocatalyst Na_0.9Mg_0.45Ti_3.55O₈ (NMTO) was prepared by a simple hydrothermal method for the first time. NMTO single crystal nanosheets with dominant {0 0 1} facets were obtained at 300 °C with 1 M NaOH over 40 min. HRTEM and XPS analyses confirmed the well crystallized nanosheets. NMTO was demonstrated as a direct semiconductor with a band gap of about 3.55 eV. Pure NMTO exhibited high photodegradation ability for methylene blue (MB) under UV-visible light irradiation. The trapping experiments indicated that the photogenerated holes were mainly responsible for the MB photodegradation. The presence of H₂O₂ significantly improved the photocatalytic activity of NMTO by inhibiting the electron–hole recombination through capturing the photogenerated electrons. A possible mechanism for the photodegradation of MB over NMTO is proposed. This work highlights the potential application of NMTO in the field of energy conversion.