In situ growth and activation of an amorphous MoSx catalyst on Co-containing metal–organic framework nanosheets for highly efficient dye-sensitized H2 evolution

Abstract

In situ grown amorphous molybdenum sulfide (MoS_x) catalysts obtained by a photoreduction method have shown photocatalytic H₂ evolution activity comparable to noble metals; however, the activity of the MoS_x catalysts is still low due to the inevitable aggregation and the low intrinsic activity of active sites. Here, we report that in situ growth and activation of MoS_x on ultrathin Co-containing metal–organic framework nanosheets (Co-BDC NSs, BDC: 1,4-benzenedicarboxylic acid) leads to the formation of a highly active H₂ evolution catalyst (Co-BDC NSs/MoS_x) in an erythrosin B-triethanolamine (ErB–TEOA) system under visible light irradiation (λ ≥ 450 nm). During the photochemical synthesis of the Co-BDC NSs/MoS_x catalyst, the ultrathin Co-BDC NSs can not only provide a large surface area to effectively anchor MoS_x nanoparticles with a reduced size and a high dispersion, but also afford abundant coordinatively unsaturated and active Co sites to form highly active “CoMoS” sites; as a result, the Co-BDC NSs/MoS_x catalyst exhibits a ∼20 times higher H₂ evolution activity than free MoS_x and an apparent quantum yield (AQY) of 15.0% at 500 nm. This work presents an efficient strategy to design highly efficient MoS_x-based hybrid catalysts for solar photocatalytic H₂ evolution reactions.