Dual plasmonic Au and TiN cocatalysts to boost photocatalytic hydrogen evolution.

Employing a suitable cocatalyst is very important to improve photocatalytic H evolution activity. Herein, two plasmonic cocatalysts, Au nanoparticles and TiN nanoparticles were in-situ coupled over the g-CN nanotube to form a ternary 0D/0D/1D Au/TiN/g-CN composite via a successive thermal polycondensation and chemical reduction method. The g-CN nanotube acted as a support for the growth of Au and TiN nanoparticles, leading to intimate contact between g-CN nanotube with Au nanoparticles and TiN nanoparticles. As a result, multiple interfaces and dual-junctions of Au/g-CN Schottky-junction and TiN/g-CN 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-CN composite exhibited significantly enhanced photocatalytic H evolution activity (596 μmol g h) compared to g-CN or binary composites of Au/g-CN and TiN/g-CN. This work highlights the significant role of cocatalysts in photocatalysis.