Electrochemical Exfoliation of Layered Black Phosphorus into Phosphorene

Abstract

Among 2D materials that recently have attracted enormous interest, black phosphorus (BP) is gaining ar ising popularity due to its tunable band-gap structure,w hich is strongly correlated to the thickness and can enable its use in optoelectronic and electronic applications.I ti st herefore important to provide af acile and scalable methodology to prepare single or few-layer BP nanosheets.W epropose herein as imple and fast top-down method to exfoliate aB Pc rystal into nanosheets of reduced thickness by using electrochemistry. The application of an anodic potential to the crystal in an acidic aqueous solution allows control over the exfoliation efficiency and quality of the nanosheets produced. X-ray photoelectron spectroscopy( XPS), Raman spectroscopy, and scanning transmission electron microscopy(STEM) have been applied to fully characterize the exfoliated material, which presented significantly reduced layer thickness compared to the starting bulk material.

Emerging 2D Materials Produced via Electrochemistry

“…The intercalation of sulfate ions led to few‐layer BP sheets with dimensions of 5–10 µm . Similarly, in 2017, Ambrosi et al presented an anodic intercalation method to delaminate bulk BP crystals to few‐layer‐thick BP nanosheets in 0.5 m sulfuric acid . However, the exfoliated sheets by these methods have a high density of functional groups, according to the strong oxidation peak in X‐ray photoelectron spectroscopy (XPS) spectra.…”

Chemistry of Layered Pnictogens: Phosphorus, Arsenic, Antimony, and Bismuth

“…The covalent functionalization of black phosphorus was reported using electrochemical fluorination in an ionic liquid . This method provides an effective and scalable functionalization of BP by fluorine atoms.…”

Electrochemical Exfoliation of MoS2 Crystal for Hydrogen Electrogeneration

“…[23] Intercalation/exfoliation with Li-based organic solvents is certainly more efficient with large amount of single or few-layer thick nanosheets obtained. Extremelyp owerful when appliedf or the exfoliation of graphite to obtain graphene, [27,28] is recently being considered also for the exfoliation of other layered materials such as Bi 2 Se 3 ,B i 2 Te 3 , [29] black phos-phorous [30] andM oS 2 , [31,32] showingp otentiality as universal procedure for fast and efficient top-down method. [25,26] Another procedure which demonstrated excellent resultsi n terms of quality of the exfoliated material, high yields,s imple operations and lower environmental impact is represented by the electrochemical-assisted exfoliation.…”