A novel all-solid-state S-scheme in CdS/ZnTHPP binary nanosystem for hydrogen evolution

The development of a highly active and stable hydrogen evolution photocatalyst is a key issue for achieving efficient and comprehensive water splitting, and it is still challenging for the scientific community and practical applications. Herein, we build up a novel visible-light-driven S-scheme in CdS/ZnTHPP binary nanosystem by simple sintering process ensuring the fast transfer of the photo-generated carriers, showing dark green upon simulated sunlight irradiation. Under an optimal condition, the highest hydrogen evolution turnover number (TON) reaches around 22,264 during 128 h irradiation, and the H2 evolution rates of the best CdS/ZnTHPP binary nanosystem was boosted up to a 400 mmol/g under irradiation for 8 hours with a conversion rate over 10-fold-higher than that of pristine CdS NRs. The macrocyclic compound serves as a region of electron absorption assisting the fast and continuous consumption of photo-generated electrons in this system, thereby concurrently alleviating the recombination of electron-hole pairs. Theoretical analyses reveal that the active sites and the generation of H2 are controlled by the thermodynamic process. This new finding provides a new approach to rationally designing an efficient solar-to-chemical conversion system.