Dual plasmonic Au and TiN cocatalysts to boost photocatalytic hydrogen evolution

Employing a suitable cocatalyst is very important to improve photocatalytic H₂ evolution activity. Herein, two plasmonic cocatalysts, Au nanoparticles and TiN nanoparticles were in-situ coupled over the g-C₃N₄ nanotube to form a ternary 0D/0D/1D Au/TiN/g-C₃N₄ composite via a successive thermal polycondensation and chemical reduction method. The g-C₃N₄ nanotube acted as a support for the growth of Au and TiN nanoparticles, leading to intimate contact between g-C₃N₄ nanotube with Au nanoparticles and TiN nanoparticles. As a result, multiple interfaces and dual-junctions of Au/g-C₃N₄ Schottky-junction and TiN/g-C₃N₄ ohmic-junction were constructed, which helped to promote the charged carriers' separation and enhanced the photocatalytic performance. Furthermore, loading plasmonic cocatalysts of Au nanoparticles and TiN nanoparticles can enhance the light absorption capacity. Consequently, the Au/TiN/g-C₃N₄ composite exhibited significantly enhanced photocatalytic H₂ evolution activity (596 μmol g^-1 h^-1) compared to g-C₃N₄ or binary composites of Au/g-C₃N₄ and TiN/g-C₃N₄. This work highlights the significant role of cocatalysts in photocatalysis.