Atomically Thin 2D-Arsenene by Liquid-Phased Exfoliation: Toward Selective Vapor Sensing

Phosphorene and antimonene, single- or few-layered (FL) semiconductor materials, have recently attracted enormous attention due to their unique properties, provided by their extreme thinness. Here, a liquid-phase exfoliation (LPE) procedure to prepare FL arsenene, another member of pnictogens, assisted by sonication and without any additional surfactant is reported. The exfoliation process is performed in various solvents. Among those, N-methylpyrrolidone is found to provide the highest concentration of stable arsenene sheets. Spectroscopic and microscopic analyses confirm the formation of high-quality few-layer arsenene nanosheets with large lateral dimensions. An application of this material for construction of vapor sensor based on electrochemical impedance spectroscopy is demonstrated. The device detects selectively methanol or acetone vapors depending on the selected resonance frequency. The results are highly reproducible, and the vapor sensor has long-term stability.