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

Highlights: • MoS₂ is directly grown onto the CdS QD by a facile photodeposition method. • The intimate interfacial contact promotes the charge transfer between CdS and MoS₂. • The MoS₂ provide abundant catalytic sites for CdS QDs towards H₂ evolution. • The CdS/MoS₂ composites exhibit excellent catalytic performance. 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.