Scalable Patterning of MoS₂ Nanoribbons by Micromolding in Capillaries

In this study, we report a facile approach to prepare dense arrays of MoS₂ nanoribbons by combining procedures of micromolding in capillaries (MIMIC) and thermolysis of thiosalts ((NH₄)₂MoS₄) as the printing ink. The obtained MoS₂ nanoribbons had a thickness reaching as low as 3.9 nm, a width ranging from 157 to 465 nm, and a length up to 2 cm. MoS₂ nanoribbons with an extremely high aspect ratio (length/width) of ∼7.4 × 10⁸ were achieved. The MoS₂ pattern can be printed on versatile substrates, such as SiO₂/Si, sapphire, Au film, FTO/glass, and graphene-coated glass. The degree of crystallinity of the as-prepared MoS₂ was discovered to be adjustable by varying the temperature through postannealing. The high-temperature thermolysis (1000 °C) results in high-quality conductive samples, and field-effect transistors based on the patterned MoS₂ nanoribbons were demonstrated and characterized, where the carrier mobility was comparable to that of thin-film MoS₂. In contrast, the low-temperature-treated samples (170 °C) result in a unique nanocrystalline MoS_<i>x</i> structure (<i>x</i> ≈ 2.5), where the abundant and exposed edge sites were obtained from highly dense arrays of nanoribbon structures by this MIMIC patterning method. The patterned MoS_<i>x</i> was revealed to have superior electrocatalytic efficiency (an overpotential of ∼211 mV at 10 mA/cm² and a Tafel slope of 43 mV/dec) in the hydrogen evolution reaction (HER) when compared to the thin-film MoS₂. The report introduces a new concept for rapidly fabricating cost-effective and high-density MoS₂/MoS_<i>x</i> nanostructures on versatile substrates, which may pave the way for potential applications in nanoelectronics/optoelectronics and frontier energy materials