Porous carbon-doped TiO2 on TiC nanostructures for enhanced photocatalytic hydrogen production under visible light

Abstract

Titanium dioxide (TiO2) has been widely investigated as a photocatalyst material because of its stability and hypotoxicity. However, the photocatalytic activity of TiO2 is suppressed by the large band gap and the high recombination rate of the charge carrier, which leads to confined application. Moreover, how to improve photocatalytic H2 production without any co-catalyst remains a big challenge. Here, we report a conceptual strategy in a core–shell nanostructure of simultaneously reducing the band gap and the charge carrier recombination rate by introducing a carbon-doped porous TiO2 layer onto a metallic TiC nanostructure using a facile in situ thermal growth method. TiC@C-TiO2 core–shell nanostructure materials have higher photocatalytic activity in methanol aqueous solution than those of pure P25 and carbon-doped TiO2, which results from enhanced visible light absorption, drastic charge transfer, and the large surface area. Notably, the novel core–shell nanostructures still exhibit excellent photocatalytic H2 production without Pt co-catalyst. The results demonstrate that TiC is an ideal support for TiO2 photocatalysts, and this novel core–shell nanostructure can significantly shift the position of the band edge of the obtained material. This study presents a design principle for photocatalytic materials as highly efficient visible light photocatalysts.