Phosphorene has attracted great interest in the rapidly emerging field of two-dimensional layered nanomaterials. Recent studies show promising electrocatalytic activity of few-layered phosphorene sheets toward the oxygen evolution reaction (OER). However, controllable synthesis of mono/few-layered phosphorene nanostructures with a large number of electrocatalytically active sites and exposed surface area is important to achieve significant enhancement in OER activity. Here, a novel strategy for controlled synthesis and in situ surface functionalization of phosphorene quantum dots (PQDs) using a single-step electrochemical exfoliation process is demonstrated. Phosphorene quantum dots functionalized with nitrogen-containing groups (FPQDs) exhibit efficient and stable electrocatalytic activity for OER with an overpotential of 1.66 V @ 10 mA cm-2, a low Tafel slope of 48 mV dec-1, and excellent stability. Further, we observe enhanced electron transfer kinetics for FPQDs toward the Fe2+/Fe3+ redox probe in comparison with pristine PQDs. The results demonstrate the promising potential of phosphorene as technologically viable OER electrodes for water-splitting devices.
Bibliographical noteFunding Information:
M.M.S. acknowledges financial support from Science and Engineering Research Board (SERB), Department of Science & Technology, Govt. of India (EMR/2017/000484), and Indian Institute of Science Education and Research (IISER), Thiruvananthapuram, Kerala, India. We acknowledge the computational resources of the IDRIS computer center of France and of the ROMEO computer center at Reims Champagne−Ardenne.
© 2018 American Chemical Society.
- black phosphorus
- electrochemical exfoliation
- oxygen evolution reaction
- quantum dots