Effect of Ag₂S on solar-driven photocatalytic hydrogen evolution of nanostructured CdS

Nanostructured Ag₂S/CdS were synthesized by a two-step precipitation method, and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV–Vis absorption spectra. With Ag₂S highly dispersed in the CdS nanostructures, the photoactivity was evaluated by hydrogen evolution from aqueous solution containing Na₂S/Na₂SO₃ as a hole scavenger under simulated solar light (AM1.5). When the concentration of Ag₂S was 5% by weight, Ag₂S/CdS showed the highest photocatalytic activity for hydrogen evolution, with the solar-hydrogen energy conversion efficiency approximately 0.7%. We investigated the effect of highly dispersed Ag₂S on the photoactivity.