Electrochemical activation strategy assisted morphology engineering Co-Fe layered double hydroxides for oxygen hydrogen evolution and supercapacitor

Regulating the intrinsic properties of the transition-metal layered double hydroxide (LDH) material is a promising strategy to improve the performance of oxygen evolution reaction (OER) and supercapacitor. Herein, a facile, low-cost and convenient electrochemical cyclic voltammetry (CV) activation strategy is reported. We demonstrate that electrochemical activation could regulate the morphology, crystal structure and electronic states of the Co-Fe layered double hydroxides (CoFe-LDH), thus significantly increasing the active site and electron transfer rate. As a result, in 1 M KOH, after 200 cycles CV activation CoFe-LDH (CoFe-LDH-200) has extremely low overpotential (360 mV at 100 mA cm(-2)) and Tafel slope (38.6 mV dec(-1)). Meanwhile, the CoFe-LDH-200 has the specific capacitance of 4662.2 mF cm?2 and good cycle sta-bility (133.8 % after 10,000 cycles). Therefore, this method opens a novel insight for developing LDH in the field of supercapacitor and electrochemical water splitting. (c) 2022 Published by Elsevier Inc.

Automated summary

Electrochemical activation can regulate the morphology, crystal structure, and electronic states of Co-Fe layered double hydroxides, resulting in increased active sites and electron transfer rate, leading to improved performance in oxygen evolution reaction and supercapacitors.