Visible light active and noble metal free Nb4N5/TiO2 nanobelt surface heterostructure for plasmonic enhanced solar water splitting

Abstract

Cocatalysts were conventionally considered as a major player in promoting the separation of photogenerated carriers, with little or no contribution to enhancing light absorption. In this work, an Nb4N5/TiO2 nanobelt heterostructure was successfully constructed. It was first demonstration of metallic Nb4N5 as a cocatalyst by separating and sustaining the transfer of photocharge carriers, and as a plasmonic booster increasing visible light absorption. The Nb4N5/TiO2 heterostructure demonstrates an excellent performance of H2 production under UV–vis light (about 108.13 μmol/g/h) around 8.5 times that of the pure TiO2 nanobelt (about 12 μmol/g/h). Such a high photocatalytic activity, as validated by various experimental methods, mainly arise from improved charge separation efficiency, more photocatalytic active sites and wider light absorption spectral range. Furthermore, through the ESR test, we confirmed that photocatalytic H2 production activity is mainly related to the ROS of OH. This work provides a facile and controllable synthesis method for manufacturing high performance photocatalyst, with mass-productive characters, which will have potential applications in synthesis cleaning/solar fuel, and photocatalytic water treatment.