Improved Photocatalytic Hydrogen Evolution on CdS Nanorods by Constructing a Proton Shuttle Layer

The photocatalytic hydrogen evolution reaction (HER) from renewable biomass resources has received considerable attention. However, the design of effective and visible-light-responsive photocatalysts continues to pose significant challenges, particularly due to limited surface reaction efficiency. A strategy is introduced to enhance the photocatalytic HER activity on CdS nanorods by constructing a surficial proton shuttle layer. Surface sulfur atoms are oxidized to form a [SO4]/[SO4–H] proton shuttle layer through plasma oxidation in air, followed by acid treatment. The resulting [SO4–H]/CdS structure facilitates improved electron–hole separation and enhances proton transfer from the liquid phase to the surface, leading to a substantial increase in HER performance. The HER rate over [SO4–H]/CdS is measured at 21.9 mmol g–1·h–1, which is approximately 100 times higher than that of pristine CdS under the same photocatalytic conditions in the presence of ethanol. This study demonstrates the effectiveness of the surficial proton shuttle layer in boosting HER activity and presents a practical method for improving the photocatalytic efficiency of metal sulfide-based systems.