Ultrathin 2D Violet Phosphorus Nanosheets: Facile Liquid‐Phase Exfoliation, Characterization, and Photoelectrochemical Application

Abstract Violet phosphorus (VP) is a stable layered van der Waals phosphorus allotrope with unique electronic and optoelectronic properties. In this study, 2D VP nanosheets (NSs) are prepared by liquid phase exfoliation (LPE) method under ambient conditions. The prepared VP NSs are characterized and utilized for photoelectrochemical (PEC)‐type photodetector (PD). The systematic PEC measurements reveal that the as‐prepared VP‐based PD shows tunable photo‐response activities from ultraviolet to visible region. A current density of 0.52 µA cm⁻², a photo‐responsivity of 31.70 µA W⁻¹, and a detectivity of 7.92 × 10¹⁰ Jones can be obtained in 1.0 m KOH under 350 nm irradiation at 0 V, revealing the good self‐powered capability of VP‐based PD. Furthermore, the cycle and time stability tests exhibit the good chemical and environmental stability of the as‐prepared PD via processing 10 000 s on/off switching and placing after one month. It is expected that this work can offer an understanding of a PEC‐type VP NSs‐based PD, and highlight the further promising applications of 2D VP NSs for other optoelectronic devices.