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

We report CdS nanorods encapsulated in a thin amorphous t-phased CNx layer modified with Pt nanoparticles (CdS/CNx-Pt) as photocatalysts for hydrogen production in 0.35 M Na2S and 0.25 M Na2SO3 solution. Compared to CdS/Pt counterparts, the CdS/CNx-Pt catalysts deliver more efficient and extraordinary stabilized catalytic activity. Herein, the t-CNx 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.