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 MoS2 nanosheets via an organic matrix-facilitated deposition followed by ultrasonic exfoliation strategy. MoS2 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 MoS2 2D nanosheets. Furthermore, the electronic structures of the ultrathin MoS2 nanosheets can be tuned via controlling their immediate environment in assemblies. In the layer-by-layer interfacial assemblies of (PEDOT:PSS/MoS2)n multilayers, the catalytic efficiency of MoS2 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 MoS2 nanosheets promote the research of functional materials based on MoS2 nanosheets and can be extended to the preparation of other nanosheet materials.