A facile preparation method for MoS2 nanosheets and their well-controllable interfacial assembly with PEDOT: PSS for effective electrochemical hydrogen evolution reactions

Transitional metal sulfide ultrathin structures present various advantageous functional properties and hold great promise in energy conversion reactions, but their facile and large-scale preparation are still challenging. Herein, a facile strategy is developed for the preparation of ultrathin MoS 2 nanosheets via an organic matrix-facilitated deposition followed by ultrasonic exfoliation strategy. MoS 2 nanosheets with lateral dimensions around 100 nm and thickness around 10–20 nm are facilely obtained. They present the typical multiple absorbance indicating the unique band structure characteristics of MoS 2 2D nanosheets. Furthermore, the electronic structures of the ultrathin MoS 2 nanosheets can be tuned via controlling their immediate environment in assemblies. In the layer-by-layer interfacial assemblies of (PEDOT:PSS/MoS 2 )n multilayers, the catalytic efficiency of MoS 2 nanosheets is enhanced by a charge transfer process as corroborated by DFT simulation. The catalytic capabilities of the assemblies are optimized by the well-controlled layer-by-layer process and present effective and stable electrochemical HER properties. We expect that this fabrication strategy of 2D MoS 2 nanosheets promote the research of functional materials based on MoS 2 nanosheets and can be extended to the preparation of other nanosheet materials.