Non-metal plasmonic TiN sensitized 2D CdS nanosheet arrays for efficient visible light-driven photoelectrochemical hydrogen evolution and photocatalytic degradation performance

Abstract

Here, a novel non-metal plasmonic TiN sensitized two-dimensional (2D) CdS nanosheet arrays (NSAs) were constructed for high-efficiency photoelectrochemical (PEC) hydrogen evolution as well as photocatalytic pollutant degradation under bias-free visible light illumination for the first time. For this patent heterogeneous nano-structures, the large surface area enables 2D CdS NSAs further to facilitate visible light absorption, as well as afford much active regions to absorb TiN nanoparticles (NPs) for boosting light energy utilization through the wide surface plasmon resonance (SPR) absorption feature of TiN. Additionally, the numerous SPR-induced TiN hot electron injection into 2D CdS efficiently augment carrier concentration. Moreover, the establishment of Schottky junction between CdS nanosheet and TiN NPs is in favour of charge migration and separation. The optimized 2D CdS/TiN NSAs achieved an obviously enhanced hydrogen production rate up to 217.2 ​μmol ​h⁻¹, 2.02-fold higher than that of pure 2D CdS NSAs. Furthermore, the organic dye Congo red degradation efficiency on the 2D CdS/TiN NSAs reached up to 93.1 ​% under visible light irradiation for 120 ​min. The remarkably enhanced photocatalytic pollutant degradation and PEC hydrogen evolution of the 2D CdS/TiN NSAs can be attributed to the cooperative action of CdS/TiN Schottky junction and SPR effect of TiN. The demonstrations of present study offer new insights into designing non-metal-based plasmonic photocatalysts for high-efficiency PEC hydrogen generation and photocatalytic pollutant degradation from the perspectives of the visible light absorption and carrier separation and injection.