Fabrication of Au@CdS/RGO/TiO2 heterostructure for photoelectrochemical hydrogen production

Abstract

This study reports a novel Au@CdS/RGO/TiO₂ heterostructure as a photoelectrode for photoelectrochemical (PEC) hydrogen generation via water splitting. The unique heterostructures of the Au@CdS/RGO/TiO₂ photoelectrode were confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Au@CdS nanoparticles with a core–shell structure were introduced into the TiO₂ photoelectrode for the first time, and the Au@CdS nanoparticles could endow the TiO₂ photoelectrode with both visible light response ability and the plasmonic property. Moreover, the RGO thin film sandwiched between TiO₂ nanorod and Au@CdS core–shell nanoparticles played an important role in the fast transport of photogenerated charges, due to its excellent electrical conductivity. Clear enhancements of photocurrent and monochromatic incident photon-to-photocurrent efficiency were observed, resulting from the synergistic effect between Au@CdS core–shell nanoparticles and the RGO thin film. More importantly, Au@CdS/RGO/TiO₂ photoelectrode achieved a considerable hydrogen evolution rate (4.821 mmol h⁻¹ m⁻²) under full spectrum illumination (47 mW cm⁻²).