Lithiation-induced amorphization of Pd₃P₂S₈ for highly efficient hydrogen evolution

Engineering material structures at the atomic level is a promising way to tune the physicochemical properties of materials and optimize their performance in various potential applications. Here, we show that the lithiation-induced amorphization of layered crystalline Pd₃P₂S₈ activates this otherwise electrochemically inert material as a highly efficient hydrogen evolution catalyst. Electrochemical lithiation of the layered Pd₃P₂S₈ crystal results in the formation of amorphous lithium-incorporated palladium phosphosulfide nanodots with abundant vacancies. The structure change during the lithiation-induced amorphization process is investigated in detail. The amorphous lithium-incorporated palladium phosphosulfide nanodots exhibit excellent electrocatalytic activity towards the hydrogen evolution reaction with an onset potential of -52 mV, a Tafel slope of 29 mV dec^-1 and outstanding long-term stability. Experimental and theoretical investigations reveal that the tuning of morphology and structure of Pd₃P₂S₈ (for example, dimension decrease, crystallinity loss, vacancy formation and lithium incorporation) contribute to the activation of its intrinsically inert electrocatalytic property. This work provides a unique way for structure tuning of a material to effectively manipulate its catalytic properties and functionalities.