Mn0.5Cd0.5S@NiO composite for boosting visible-light-driven photocatalytic hydrogen evolution

Abstract

The MnxCd1-xS solid solution is a recently emerged semiconductor with an adjustable bandgap structure, which has great potential for development in the photocatalytic water splitting field. In the present study, a Mn0.5Cd0.5S@NiO composite was constructed through a solvothermal method for efficient visible-light-driven photocatalytic hydrogen evolution. The study results revealed that Mn0.5Cd0.5S@NiO composite possessed excellent photostability, more active sites, reduced recombination and fast charge-separation compared to pure Mn0.5Cd0.5S. As a result, the Mn0.5Cd0.5S@NiO-0.50 composite exhibited significant hydrogen evolution activity upon exposure to visible light (λ ≥ 420 nm), with a rate of 50.53 mmol·g−1·h−1, which was 4.9 times and 632 times greater contrasting to the pure Mn0.5Cd0.5S and NiO, respectively. Of note, NiO exists in the form of a co-catalyst in composite materials, playing a role in accelerating the transport of photo-generated electrons and facilitating H+ reduction sites during the electron transfer process, thereby enhancing the hydrogen production rate of the photocatalyst.