Turbostratic carbon nitride enhances the performance and stability of cadmium sulfide nanorod hydrogen evolution photocatalysts

Abstract

We report CdS nanorods encapsulated in a thin amorphous t-phased CN_x layer modified with Pt nanoparticles (CdS/CN_x-Pt) as photocatalysts for hydrogen production in 0.35 M Na₂S and 0.25 M Na₂SO₃ solution. Compared to CdS/Pt counterparts, the CdS/CN_x-Pt catalysts deliver more efficient and extraordinary stabilized catalytic activity. Herein, the t-CN_x layer functions as (1) a protection layer to isolate CdS from the electrolyte and suppress the anodic photocorrosion of CdS and (2) as a tunnel junction to promote charge separation and electron transport to PtNPs for proton reduction. Surface photovoltage spectra (SPS) confirm 2.25 eV as the effective bandgap and the n-type character of the CdS nanorods. Photoelectron injection into the PtNPs and photohole injection into the sacrificial donors can be directly observed.