Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Production of CdS-Cluster-Decorated Graphene Nanosheets

TLDR

The production of clean and renewable hydrogen through water splitting using photocatalysts has attracted significant attention amid growing global energy crises. The study aims to achieve high‑efficiency photocatalytic hydrogen production by decorating graphene nanosheets with CdS clusters for visible‑light activation. The composites were synthesized solvothermally by reducing graphene oxide with cadmium acetate to form CdS clusters on graphene, and graphene serves as an electron collector that extends charge‑carrier lifetimes. The resulting CdS–graphene composites achieved a hydrogen production rate of 1.12 mmol h⁻¹—4.87 times that of pure CdS—at 1.0 wt % graphene and 0.5 wt % Pt, with an apparent quantum efficiency of 22.5 % at 420 nm, demonstrating the promise of graphene‑based materials for energy conversion.

Abstract

The production of clean and renewable hydrogen through water splitting using photocatalysts has received much attention due to the increasing global energy crises. In this study, a high efficiency of the photocatalytic H(2) production was achieved using graphene nanosheets decorated with CdS clusters as visible-light-driven photocatalysts. The materials were prepared by a solvothermal method in which graphene oxide (GO) served as the support and cadmium acetate (Cd(Ac)(2)) as the CdS precursor. These nanosized composites reach a high H(2)-production rate of 1.12 mmol h(-1) (about 4.87 times higher than that of pure CdS nanoparticles) at graphene content of 1.0 wt % and Pt 0.5 wt % under visible-light irradiation and an apparent quantum efficiency (QE) of 22.5% at wavelength of 420 nm. This high photocatalytic H(2)-production activity is attributed predominantly to the presence of graphene, which serves as an electron collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carriers from CdS nanoparticles. This work highlights the potential application of graphene-based materials in the field of energy conversion.