Highly efficient charge transfer from small-sized cadmium sulfide nanosheets to large-scale nitrogen-doped carbon for visible-light dominated hydrogen evolution

Abstract

Slow charge transfer and carrier recombination are key issues in photocatalytic reactions. The current solution is to load small-sized cocatalysts onto large-sized photocatalysts. Here a new strategy is proposed. Small-sized photocatalysts of cadmium sulfide (CdS) nanosheets are grown onto large-sized cocatalysts of N-doped amorphous carbon (a-CN) to construct CdS @ a-CN photocatalysts. Photoluminescence spectra and transient photocurrent demonstrate that optimized CdS @ a-CN shows effective charge separation compared with CdS. The corresponding photocatalytic H2 yield of optimized CdS @ a-CN is ∼244 μmol, which is 3.6 times higher than that of CdS. Besides, the hydrogen yield for CdS under visible-light irradiation is significantly improved from ∼44 μmol to ∼217 μmol for the optimized CdS @ a-CN. Our design strategy provides an effective way to construct photocatalytic systems with outstanding photocatalytic performance.