van Druenen, Maart; Davitt, Fionán; Collins, Timothy; Glynn, Colm; O'Dwyer, Colm; Holmes, Justin D.; Collins, Gillian

2019

January

Langmuir : the ACS journal of surfaces and colloids

Evaluating the surface chemistry of black phosphorus during ambient degradation

Published

()

Black phosphorus 2D materials Phosphorene Ambient stability Degradation Oxidation X-ray photoelectron spectroscopy Fourier transform infrared spectroscopy

35

2172

2178

Black Phosphorus (BP) is emerging as a promising candidate for electronic, optical and energy storage applications, however its poor ambient stability remains a critical challenge. Evaluation of few-layer liquid exfoliated BP during ambient exposure using x-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) allows its surface chemistry to be investigated. Oxidation of liquid exfoliated few-layer BP initially occurs through non-bridged oxide species, which convert to bridged oxide species after ambient exposure. We demonstrate the instability of these bridged oxide species which undergo hydrolysis to form volatile phosphorus oxides and evaporate from the BP surface. FTIR spectroscopy, scanning transmission electron microscopy and atomic force microscopy were used to confirm the formation of liquid oxides through a continuous oxidation cycle that results in the decomposition of BP. Furthermore, we show that the instability of few-layer BP originates from the formation of bridged oxide species.

0743-7463

https://doi.org/10.1021/acs.langmuir.8b04190

10.1021/acs.langmuir.8b04190