Molecular stabilization of chemically exfoliated bare MnPS3 layers

Transition metal chalcogenophosphates of general formula MPX3 have attracted recent interest in the field of 2D materials due to the possibility of tuning their properties when reaching the 2D limit. Several works address this challenge by dry mechanical exfoliation. However, only a few of them use a scalable approach. In this work, we apply a general chemical protocol to exfoliate MnPS3. The method uses in a first step chemical intercalation and liquid phase exfoliation, followed in a second step by the addition of molecules used as capping agents on the inorganic layers. Therefore, molecules of different nature prompts the quality of the exfoliated material and its stabilization in aqueous solution, opening the possibility of using these functionalized layers in several fields. Here we illustrate this possibility in electrochemistry. Thus, we show that when polyethylenimine is used as capping agent, it is possible to reach a compromise between the stability of high quality MnPS3 flakes in aqueous suspension and their optimum performance as an electrocatalytic system for HER activity.