“Giant” reverse type-I CdS/CdSe core/shell quantum dots for efficient visible light-induced hydrogen photogeneration from water

Abstract

Colloidal semiconductor quantum dots (QDs) have been considered an ideal model to unveil the detailed charge transfer dynamics for photocatalytic hydrogen evolution owing to their merits of precisely controlled band structures, high light absorption coefficients, and exceptional charge transport properties. Herein, we demonstrate that through the formation of “giant” reverse type-I CdS/CdSe core/shell QDs, the corresponding hydrogen photogeneration rate is much enhanced to 65.97 mmol·g⁻¹·h⁻¹ under the illumination of visible light (λ > 420 nm), which is 6.6-fold higher than that of CdS QDs-based system. Photoluminescence lifetime and photoelectrochemical measurements reveal that the prolonged lifetime and significantly improved separation efficiency of charge carriers are supposed to be responsible for the enhancement.