Heterostructured Monolayer MoS₂ Nanoparticles toward Water-Dispersible Catalysts

Abstract

MoS₂ is a 2D semiconductor where exfoliation to a single layer results in improved catalytic properties. However, its high surface energy can lead to extensive aggregation, resulting in degraded catalytic performance and stability. Combined with a lack of dispersibility in water, this represents a pitfall for catalysis in the aqueous phase. Herein, we present the use of nanoscopic layered silicates pillared with a cationic surfactant to template the growth of MoS₂ in the interlayer space. This provides heterostructured layered nanoparticles ∼25 nm wide by 3-8 nm thick containing isolated MoS₂ layers. The resulting nanohybrids retain the disc-like morphology and surface chemistry of the clays, providing good aqueous stability, while also providing access to the catalytic edge-sites of the MoS2 layer. In addition to significant enhancement of catalytic dye degradation, molecular aggregation on the highly charged clay interface is comparable to unmodified clays. These particles are ideal for studies of charge-transport properties in confined semiconductor layers, as well as hierarchical self-assembly into functional materials. This study paves the way to colloidal synthesis of nanoparticulate heterostructures with other functional layered materials, particularly where particle exfoliation, covalent modification, and aqueous stability are concerns.