Significantly Raised Visible-Light Photocatalytic H2 Evolution on a 2D/2D ReS2 /In2 ZnS4 van der Waals Heterostructure

Owing to dwindling fossil fuels reserves, the development of alternative renewable energy sources is globally important. Photocatalytic hydrogen (H₂ ) evolution represents a practical and affordable alternative to convert sunlight into carbon-free H₂ fuel. Recently, 2D/2D van der Waals heterostructures (vdWHs) have attracted significant research attention for photocatalysis. Here, for the first time a ReS₂ /In₂ ZnS₄ 2D/2D vdWH synthesized via a facile physical mixing is reported. It exhibits a highly promoted photocatalytic H₂ -evolution rate of 2515 µmol h^-1 g^-1 . Importantly, this exceeds that for pristine In₂ ZnS₄ by about 22.66 times. This, therefore, makes ReS₂ /In₂ ZnS₄ one of the most efficient In₂ ZnS₄ -based photocatalysts without noble-metal cocatalysts. Advanced characterizations and theoretical computations results show that interlayer electronic interaction within ReS₂ /In₂ ZnS₄ vdWH and atomic-level S active centers along the edges of ReS₂ NSs work collaboratively to result in the boosted light-induced H₂ evolution. Results will be of immediate benefit in the rational design and preparation of vdWHs for applications in catalysis/(opto)electronics.

Chemical Vapor Deposition Growth of Vertical MoS2 Nanosheets on p-GaN Nanorods for Photodetector Application

Vertically oriented multilayered MoS₂ nanosheets were successfully grown on p-GaN nanorod substrate using chemical vapor deposition (CVD) method. The p-GaN nanorod substrate was fabricated by dry etching employing self-assembled nickel (Ni) nanopartical as mask. Photoluminescence (PL) and Raman characterizations demonstrate the multilayered structure of MoS₂ nanosheet growth on p-GaN nanorods as compared with the referential monolayer MoS2 on GaN wafer substrate under the same growth procedure. The growth model of vertical MoS2 nanosheet formed on GaN nanorods is evidently proposed according to the first-principle calculations. More importantly, it is demonstrated here that the as-grown vertical MoS₂ nanosheets/p-GaN nanorod heterostructure holds promising applications in photodetector device, where high optical gain and broad spectral response in the visible range have been obtained.