Facile and green synthesis of titanate nanotube/graphene nanocomposites for photocatalytic H2 generation from water

A facile and green one-step method was used to prepare titanate nanotube/graphene (TNT/GR) photocatalysts via an alkaline hydrothermal process. The as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy and photoluminescence emission spectroscopy. The photocatalytic performance was evaluated by H2 generation from water splitting under Xe-lamp illumination. A significantly enhanced photocatalytic activity for H2 evolution (12.1 μmol/h) was obtained over the compostion-optimized TNT/GR composite (with 1.0 wt% GR), two times higher than that of pure TNT (4.0 μmol/h). During hydrothermal reaction, the reduction of graphene oxide (GO) into GR without using any reducing agents and the formation of 1-D TNT were achieved simultaneously, which resulted in the direct growth of well-defined TNTs uniformly distributed on GR substrates.