Electrochemically Exfoliated β-Co(OH)₂ Nanostructures for Enhanced Oxygen Evolution Electrocatalysis

Exploring highly efficient and low-cost electrocatalysts for the oxygen evolution reaction (OER) is very important for the development of renewable energy conversion and storage systems. Layered metal hydroxides have been studied with great interest owing to their high electrochemical activity and stability toward OER. Herein, we demonstrate an efficient approach to engineer the surface active sites in β-Co(OH)2 for enhanced electrocatalysis of OER. We employ a single-step bipolar electrochemical technique for the exfoliation of pristine β-Co(OH)2(Co(OH)2-Bulk) into thinner and smaller sheets. The as-synthesized Co(OH)2 nanostructures with improved active sites exhibit enhanced electrocatalytic activity toward OER with a very low overpotential of 390 mV at 10 mA cm–2 and a Tafel slope of 57 mV dec–1 in alkaline media. The results provide a promising lead for the development of efficient and economically viable electrode materials for oxygen evolution electrocatalysis.