In-situ-formed Cd and Ag2S decorated CdS photocatalyst with boosted charge carrier spatial separation for enhancing UV-vis-NIR photocatalytic hydrogen evolution

CdS demonstrate superior potential for H2 production, but exist deficiencies of low carrier separation efficiency and photostability limit their large-scale application. Hence, a novel Ag2S/CdS/Cd2SO4(OH)2 composite has been designed. In-depth measurements reveal that Cd2SO4(OH)2 will be in-situ reduced to Cd metal as an excellent electron trap and hydrogen production site during the photocatalytic process. As a result, photogenerated electrons and holes will directionally transfer to Cd metal and Ag2S respectively, leading to the separation of oxidation and reduction reaction sites. As expected, Ag2S/CdS/Cd2SO4(OH)2 and final Ag2S/CdS/Cd systems exhibit considerably promoted photocatalyst properties than many other CdS-based photocatalysts no matter on the illumination of UV, Vis or NIR light. The research not only provide a new insight to develop a low-cost, carrier spatial separation and full-spectrum-responsive photocatalytic hydrogen evolution system, but also displays a novel strategy for in-situ deposition of metal clusters on the photocatalyst surface during the photocatalytic process.