General and Scalable Solid-State Synthesis of 2D MPS3 (M = Fe, Co, Ni) Nanosheets and Tuning Their Li/Na Storage Properties

The scalable preparation of 2D nanomaterials is challenging and highly desirable for fundamental interest and practical applications. Herein, an efficient solid-state method is developed for producing emerging 2D ternary layered metal phosphorus trichalcogenide (MPS3, M = Fe, Co, Ni) nanosheets on a large scale. The high-quality MPS3 single-crystal nanosheets are exposed with (00l) facets and have an average lateral size of approximate to 200 nm and an average thickness of approximate to 18 nm. Moreover, their interlayer spacing can be expanded by intercalating propylamine at room temperature. For Li/Na storage applications, such MPS3 nanosheets can achieve: i) high specific capacity owing to the intrinsic composition, realizing a theoretical specific capacity higher than the corresponding metal oxides, and ii) superior rate capability due to the large extrinsic pseudocapacitive contribution from surface redox reactions. Remarkably, the propylamine-intercalated samples show improved Li/Na storage performance due to the better electrical conductivity and enlarged interlayer distance to allow easier ion accessibility and faster ion diffusion. Impressively, the Na-ion batteries based on the intercalated NiPS3 nanosheets deliver 1090 and 536 mA h g(-1) at 0.05 and 5.0 A g(-1), respectively. This work paves the way for developing MPS3 nanosheets for energy storage and conversion, catalysis, and so on.