Noble-metal-free CdS@MoS2 core-shell nanoheterostructures for efficient and stabilized visible-light-driven H2 generation

Photocatalytic water splitting is considered to be a green H-2 generation approach and has potential to be applied in the future. As a photocatalytic active material for H-2 evolution, CdS is a good candidate. However, the pristine CdS still suffers from low efficiency and poor stability. To address those issues, we developed noble-metal-free CdS@MoS2 core-shell nanoheterostructures which exhibit outstanding photocatalytic H-2 evolution performance thus far with rate of 62.55 mmol g(-1) h(-1), which exceeds that of pristine CdS by a factor of 148. Meanwhile, the photocatalytic stability can be well retained with no deterioration of activity in 24 h reaction. The excellent performance can be reasonably attributed to the low crystallinity of MoS2 with numerous active sites provided, and the band alignment of CdS and MoS2 as determined by valence band-XPS and Mott-Schottky plots analysis, which significantly promotes charge transportation and separation. The enhanced photocatalytic stability here should be ascribed to the intimate growth of MoS2 shells which significantly passivate the surface trap states of CdS cores and thus the photocorrosion is remarkably retarded. This novel strategy will inspire the fabrication of other photocatalytic systems, and may high-efficient photocatalysts be obtained. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.