Facile preparation of NH2-functionalized black phosphorene for the electrocatalytic hydrogen evolution reaction

Abstract

A new facile and green solid exfoliation method using urea-assisted ball milling is reported here to prepare NH₂-functionalized few-layer black phosphorus (BP) nanosheets. The thickness of the obtained nanosheets is about 2.15–4.87 nm. The NH₂-BP nanosheets exhibit enhanced electrocatalytic hydrogen evolution reaction (HER) performance with an overpotential of 290 mV at −10 mA cm⁻², a Tafel slope of 63 mV dec⁻¹ and a turnover frequency of 3.21 s⁻¹ at an overpotential of 290 mV, which drastically surpass those of the bulk BP. This electrocatalytic activity of NH₂-BP nanosheets in alkaline electrolyte greatly outperforms that in acidic electrolyte, making it a promising metal-free HER catalyst.