Unique hollow heterostructured CdS/Cd0.5Zn0.5S-Mo1−xWxS2: Highly-improved visible-light-driven H2 generation via synergy of Cd0.5Zn0.5S protective shell and defect-rich Mo1−xWXS2 cocatalyst

Abstract

Photocatalytic water splitting for hydrogen (H2) production is a green sustainable technology, in which highly-efficient steady photocatalysts are fundamentally required. In this work, unique CdS/Cd0.5Zn0.5S-Mo-1−xWxS2 photocatalyst constructed by CdS hollow nano-spheres with successively surface-modified Cd0.5Zn0.5S shell and defect-rich Mo1−xWxS2 ultrathin nanosheets was reported for the first time. Interestingly, the Cd0.5Zn0.5S shell could greatly enhance the photo-stability and reduce the carrier recombination of CdS. Meanwhile, enriching active sites and accelerating charge transfer could be achieved via anchoring defect-rich Mo1−xWxS2 onto CdS/Cd0.5Zn0.5S hollow heterostructures. Specifically, the optimized CdS/Cd0.5Zn0.5S-Mo1−xWxS2 (6 h Cd0.5Zn0.5S-coating, 7 wt.% Mo1−xWxS2, x = 0.5) hybrid delivered an exceptional H2 generation rate of 215.99 mmol·g−1·h−1, which is approximately 502, 134, and 23 times that of pure CdS, CdS/Cd0.5Zn0.5S, and 3 wt.% Pt-loaded CdSZCd0.5Zn0.5S, respectively. Remarkably, a high H2 evolution reaction (HER) apparent quantum yield (AQY) of 64.81% was obtained under 420-nm irradiation. In addition, the CdS/Cd0.5Zn0.5S-Mo1−xWxS2 was also durable for H2 production under long-term irradiation. This work provides valuable inspirations to rational design and synthesis of efficient and stable hybrid photocatalysts for solar energy conversion.