High-Yield Exfoliation of Ultrathin 2D Ni<inf>3</inf>Cr<inf>2</inf>P<inf>2</inf>S<inf>9</inf> and Ni<inf>3</inf>Cr<inf>2</inf>P<inf>2</inf>Se<inf>9</inf> Nanosheets

Abstract

Multinary layered 2D nanomaterials can exhibit distinct physicochemical properties and innovative applications as compared to binary 2D nanomaterials due to their unique crystal structures. However, it still remains a challenge for the high-yield preparation of high-quality multinary 2D nanosheets. Here, the high-yield and large-scale production of two quaternary metal thiophosphate nanosheets are reported, i.e., Ni3Cr2P2S9 and Ni3Cr2P2Se9, via the liquid exfoliation of their layered bulk crystals. The exfoliated single-crystalline Ni3Cr2P2S9 nanosheets, with a lateral size ranging from a few hundred nanometers to a few micrometers and thickness of 1.4 ± 0.2 nm, can be easily used to prepare flexible thin films via a simple vacuum filtration process. As a proof-of-concept application, the fabricated thin film is used as a supercapacitor electrode with good specific capacitance. These high-yield, large-scale, solution-processable quaternary metal thiophosphate nanosheets could also be promising in other applications like biosensors, cancer therapies, and flexible electronics.