One-pot hydrothermal synthesis of MoS2-modified Mn0.5Cd0.5S solid solution for boosting H2 production activity under visible light

Abstract

The development of low-cost and highly efficient photocatalysts with a visible-light-responsive feature for H₂ production from water photosplitting is an interesting but challenging research topic. In this study, a series of Mn_xCd_1−xS products (0 ≤ x ≤ 1.0) have been prepared by a facile hydrothermal method, and the resultant Mn_0.5Cd_0.5S solid solution exhibits the highest photocatalytic H₂ production activity (286 μmol h⁻¹), which is 1.83 times higher than that (156 μmol h⁻¹) of single CdS under visible light (λ ≥ 420 nm) irradiation. After being modified with MoS₂via a one-pot hydrothermal process, the MoS₂-modified Mn_0.5Cd_0.5S (MoS₂/Mn_0.5Cd_0.5S) composites achieve remarkable improvement in their photocatalytic performance under λ ≥ 420 nm light irradiation, and the 0.5 wt% MoS₂/Mn_0.5Cd_0.5S displays the highest H₂ production activity (491 μmol h⁻¹), which is much higher than that (286 μmol h⁻¹) of pristine Mn_0.5Cd_0.5S and also slightly higher than that (417 μmol h⁻¹) of 1.0 wt% Pt/Mn_0.5Cd_0.5S. The intimate interfacial contact between Mn_0.5Cd_0.5S nanoparticles and few-layer MoS₂ cocatalysts formed during the one-pot hydrothermal process facilitates the electron transfer from Mn_0.5Cd_0.5S to MoS₂, and thus promotes the photogenerated charge separation and provides more active sites for H₂ evolution reaction. This work demonstrates that low cost and earth-abundant MoS₂ as an effective cocatalyst can replace noble metals for visible-light-driven H₂ production over Mn_xCd_1−xS solid solutions.