Highly efficient visible light hydrogen production from water-splitting: Structure and composition regulation of Pt-based cocatalyst

Abstract

Pt-based nanoframes (NFs) have the advantages of high atomic utilization, more unsaturated coordination sites and open space structure, and have achieved wide applications in thermal/electrocatalysis. Herein, Pt3Pd NFs coupled with CdS was applied in hydrogen generation from water-splitting under visible light, and it exhibits an excellent hydrogen generation rate, 92.5 mmol/h/g (AQY = 65.9%, λ = 420 nm). The synthesis of Pt3Pd NFs cocatalyst underwent the following processes: the formation of Pd nanocubes (NCs), PtPd4 NCs by site-selected deposition of Pt atoms on the edges of Pd NCs, and the target Pt3Pd NFs enclosed by {200} with an average size of 18 nm was obtained via internal etching. The structure and composition of Pt3Pd NFs were analyzed using TEM, XRD and XPS, and the charge transfer and separation mechanism were also investigated by electrochemical workstation, ESR and work function. The testing results indicated that Pt3Pd NFs cocatalyst acting as trapping centers benefit the electrons transfer, and thus promote the separation efficiency of photo-induced carriers. This work reveals that the structure and composition regulation of Pt-based cocatalyst plays a vital role in its active performance.