Ultrathin MoS2 Nanosheets via Lamp Ablation

We report innovative results for the synthesis of ultrathin molybdenum disulfide nanosheets (MoS₂-NS) from the innovative and potentially scalable process of high-temperature lamp ablation. These findings could refashion the restrictive reality of MoS₂-NS synthesis, which is currently based on methods with practical limitations that have impeded large-scale impact and commercialization. These constraints include being intrinsically small-scale, requiring toxic reagents, very long process times, and complex multistep reactors. MoS₂-NS have properties suited to exceptional catalytic performance and highly selective membranes. High-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, high-angle annular dark field imaging, scanning electron microscopy, Raman spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis were used to analyze and characterize the MoS₂-NS. Our products also included monolayer MoS₂, which has been shown to exhibit optical and physicochemical characteristics distinct from bi- and multilayer MoS₂. A formation mechanism is proposed wherein high-temperature thermal exfoliation overcomes the weak van der Waals forces between MoS₂ layers, leading to the formation of nanosheets. This also accounts for the experimental fact that no nanostructures, aside from nanosheets, were observed. Our lamp ablation system points to the prospect of achieving scaled-up production that could transition MoS₂-NS from laboratory benchtop achievements to high-impact industrial-level products.