Simultaneous Preparation and Functionalization of Ultrathin Few-layer Black Phosphorus Nanosheets and Their Electrocatalytic OER and HER Performance

A convenient liquid phase exfoliation method is reported here to prepare functionalized few-layer black phosphorus (BP) nanosheets by using succinic acid (SA) or L-ascorbic acid (L-AA) -assisted tip-ultrasonicated exfoliation. The thickness of the obtained nanosheets is about 2-2.5 nm, which is equivalent to 4-5 layers of BP atoms. And SA-BP-1 : 3 exhibits a best OER and HER performance in the group of SA-BP with different weight ratios, requiring an overpotential of 369.8 mV for OER and 235 mV for HER to achieve the current density of 10 mA cm(-2), respectively. Meantime, L-AA-BP-1 : 1 presents a great OER and HER performance in the group of L-AA-BP with different weight ratios, requiring an overpotential of 459.5 mV for OER and 224 mV for HER to achieve the current density of 10 mAcm(-2), respectively. And two groups of the samples significantly enhance the OER and HER performance of few-layer BP nanosheets (550 mV and 431 mV). In addition, both the consecutive cyclic voltammetry and chronoamperometric measurements reveal the outstanding electrocatalytic stability of the samples.

Automated summary

A convenient liquid phase exfoliation method was used to prepare functionalized few-layer black phosphorus nanosheets, which showed excellent OER and HER performance with different weight ratios of succinic acid or L-ascorbic acid. The samples significantly enhanced the electrocatalytic stability and performance of few-layer BP nanosheets.