Dual charge-accepting engineering modified AgIn5S8/CdS quantum dots for efficient photocatalytic hydrogen evolution overall H2S splitting

Low charge carrier separation and transfer efficiency continues to be the major obstacle to harvest solar energy to split hydrogen sulfide (H₂S) as hydrogen source for H₂ production with value-added utilization for waste by-products. Herein, we designed a Type-II core/shell AgIn₅S₈/CdS (AIS/CdS) quantum dots (QDs) photocatalyst capped with short-chain inorganic sulfide ion (S²⁻) ligand with dual charge-accepting engineering to promote charge carrier extraction and faster photogenerated electron transfer. Transient absorption spectroscopy analysis demonstrates that the excited electrons are fast injected into CdS shell from AIS core within 1.7 ps, instead of transferring to sub-bandgap states. Consequently, the highest photocatalytic hydrogen evolution rate of AIS/CdS QDs with S^2- ligand is 12.74 mmol g⁻¹ h⁻¹ that is more than four times of pristine AIS core. This work offers insightful guidance on the rational design of charge-accepting engineering QDs-based photocatalysts, thereby stimulating solar to hydrogen generation and resource utilization of pollutants.