Enhancement of Photocatalytic Hydrogen Generation of Ni Doped CdS Enabled By Improved Ultrafast Charge Transfer

Ultrafast carrier dynamics of Cd 0.992 Ni 0.008 S nanoparticles with and without Pt have been investigated using femtosecond transient absorption spectroscopy (fs-TA) with broadband capabilities. A strong ground state bleaching (GSB) feature around 480 nm and a broad photo-induced absorption (PIA) feature around 600 nm were assigned for electron and hole signatures in Cd 0.992 Ni 0.008 S, respectively. In order to validate the inferences made from fs-TA studies, we have examined the photo-catalytic performance of Cd 0.992 Ni 0.008 S and Pt/Cd 0.992 Ni 0.008 in the presence of a complex medium composed of acetic acid and benzyl alcohol. The results show that the Ni doping in Pt/CdS not only enhances the photocatalytic performance of the Pt/CdS but also improves the photo-stability by removing the photo-generated hole efficiently. Figure 1