Enhanced visible-light photocatalytic H2-production performance of multi-armed CdS nanorods

Abstract

Visible light photocatalytic H₂ production from aqueous solutions using solar light is of great importance from the viewpoint of solar energy conversion and storage and environment protection. In this study, a novel visible-light-driven photocatalyst, multi-armed CdS nanorods, was synthesized using a solvothermal method with dodecylamine as solvent. The prepared CdS nanorod samples showed especially high and stable photocatalytic H₂-production activity with aqueous lactic acid solution as sacrificial reagent and Pt as co-catalyst under visible light irradiation. The CdS nanorod sample prepared at 140 °C for 12 h exhibited a high H₂-production rate of 1.21 mmol h⁻¹ (about 3.2 times higher than that of CdS nanoparticles (NPs) formed in water) with a very small amount of Pt (0.23 wt%) and a quantum efficiency (QE) of 51% at a wavelength of 420 nm. This high photocatalytic H₂-production activity can be attributed to the synergistic effects of several factors such as the hexagonal phase structure, high surface area, great pore volume and good crystallization. Furthermore, the prepared CdS nanorod sample was photostable and no photocorrosion was observed after photocatalytic recycling. Our work demonstrated that multi-armed CdS nanorods were a promising candidate for the development of high-performance visible-light photocatalysts in photocatalytic H₂ production and that the morphology of the CdS nanocrystals had a great effect on the photocatalytic H₂-production activity.