In-suit photodeposition of MoS2 onto CdS quantum dots for efficient photocatalytic H2 evolution

Abstract

Photocatalytic hydrogen (H2) production from water is an appealing approach to alleviate the ever-increasing fossil fuel crisis. The development of visible-light-driven photocatalytic system is an essential task for H2 generation. CdS quantum dots (QDs) are excellent candidate for photocatalytic H2 generation. However, the photocatalytic performance of CdS QDs is largely limited by serious charge recombination and photocorrison problems. Herein, we developed a facile method for photodeposition of MoS2 onto CdS QDs. The in-suit photodeposition approach enables thin-layered MoS2 to be intimately decorated onto the CdS QD surface. The intimate contact favors the formation of junctions between CdS and MoS2, thus promoting charge separation in CdS/MoS2. Furthermore, the MoS2 catalysts can provide highly active catalytic sites for H2 evolution and serve as protective layer for CdS to restrict photocorrison. The resulted CdS/MoS2 photocatalysts exhibit excellent catalytic activity: the H2 generation rate reaches 13129 μmol h−1 g−1, which is 7.2 times higher than that of the pristine CdS-S QDs. The CdS/MoS2 photocatalysts also possess superior photocatalytic durability under visible light. This work provides a novel method for in-suit growth of MoS2 onto QDs. The surface modification strategy presented here offers new opportunities for developing new-types of photocatalysts based on QDs.