A Hybrid Photocatalyst Composed of CdS Nanoparticles and Graphene Nanoribbons for Visible-Light-Driven Hydrogen Production

Development of heterojunction photocatalysts has been an attractive research topic because of their capability of enhancing the separation and transport of photogenerated electrons and holes, which accordingly improves photocatalytic performance. Here, we constructed a hybrid heterojunction consisting of CdS nanoparticles and structurally defined graphene nanoribbons (GNRs) via a simple solvothermal method. The introduction of an appropriate amount of GNRs alleviated the aggregation of CdS nanoparticles and also broadened the absorption range of visible light. Photocurrent, electrochemical impedance, steady-state photoluminescence, and time-resolved fluorescence decay spectroscopy measurements demonstrated that the CdS/GNR heterojunction effectively alleviated the recombination of photogenerated electron-hole pairs. Remarkably, the CdS/GNR hybrid with a 10 wt % amount of GNRs plus the deposition of 1 wt % Pt exhibited excellent photocatalytic hydrogen production performance upon visible light irradiation (lambda >= 420 nm) with a H2 evolution rate up to 22.4 mmol h(-1) g(-1), which is much higher than those of separate CdS and GNRs. This study revealed a potential application of GNRs in photocatalysis and their essential role in the heterojunction catalyst with semiconductive inorganic nanoparticles.

Automated summary

The study demonstrated that the hybrid heterojunction of CdS nanoparticles and structurally defined graphene nanoribbons (GNRs) improved photocatalytic performance by enhancing separation and transport of photogenerated electron-hole pairs. The introduction of an appropriate amount of GNRs alleviated the aggregation of CdS nanoparticles and broadened the absorption range of visible light, leading to a higher hydrogen production rate.