Large-Scale Synthesis of Violet Phosphorus Nanosheets with Superior Air-Water Stability

Black phosphorus (BP) has spurred exploration of two-dimensional phosphorus allotropes but its inferior stability in air and water as well as complex exfoliation routes hinder large-scale application. Herein, violet phosphorus nanosheets (VP NSs) are synthesized by a solvothermal technique using amorphous red phosphorus and amine as the raw materials. The one-pot production weight of the VP NSs with an average lateral size of 200 nm and thickness of 15 nm can be increased to 100 grams with a high yield of >95%. The underlying mechanism of the amine promoted structure and transformation from amorphous to crystalline is investigated systemically, and an active amine screening model is proposed from the macroscopic perspective. The VP NSs exhibit superior stability in different environments including ambient conditions, humid air, aqueous solution, and light irradiation due to the weak interactions with oxygen and water molecules. Compared to emerging efficient flame retardant BP NSs, VP NSs possess better fire retarding properties. The amine-driven structural transformation paves the way for low-cost and large-scale production of nanomaterials, and the stable phosphorus allotrope is expected to have application in many and broader fields.