Carbon inserted defect-rich MoS_2-X nanosheets@CdSnanospheres for efficient photocatalytic hydrogen evolution under...

Carbon -MoS_2-x@CdS (C-MoS_2-x@CdS) core-shell nanostructures with controlled surface sulfur (S) vacancies were prepared via a glucose assisted hydrothermal growth method. The glucose acted as a reducing agent of C-MoS_2-X to partially reduce Mo⁴⁺ ions to Mo³⁺ and served as a carbon source to insert the amorphous carbon into the layered MoS_2-X simultaneously. The presence of Mo³⁺ result in the surface S-vacancies, which can provide more additional active sites and enhance the photocatalytic performance. Moreover, the inserted carbon in layered MoS_2-X enhanced the electron mobility and decreased the resistance electron transfer. Density functional theory (DFT) calculation confirmed that the surface S-vacancies and the amorphous carbon increase the projected density of states at the conduct band edge, which could enhance the photo-absorption and photo-responsibility. The result is consistent with the photocatalytic H₂ production experiment. C2-10%MoS_2-x@CdS presented a high H₂ evolution rate of 61,494 μmol h^-1 g^-1 under visible light irrigation (λ ≥ 420 nm), which is 1.98 times and 158 times higher than that of sample without S-vacancies (10%MoS₂@CdS) and pure CdS, respectively.