Conductive Metal-Organic-Frameworks Enhanced Highly Efficient Electrocatalytic Performance of Hollow CoNiFe-LDH Nanocages for Oxygen Evolution Reaction

Layered double hydroxides (LDH) have attracted great research interest as catalysts for electrochemical water splitting. However, further enhancing the electrocatalytic activity of LDH materials is still a huge challenge. Here, we designed a mild wet chemical route to successfully prepare conductive metal-organic frameworks (cMOFs) modified hollow CoNiFe-LDH nanocages.Firstly, ZIF-67 nanocubes were etched by Ni 2+ and Fe 3+ ions in turn to form hollow CoNiFe-LDH nanocages. Then, hollow CoNiFe-LDH nanocages reacted with 2,3,6,7,10,11hexahydroxytriphenylene (HHTP) to obtain cMOFs modified hollow CoNiFe-LDH nanocages (labeled as CoNiFe-HHTP). Electrochemical measurements showed that the as-obtained CoNiFe-HHTP exhibited excellent electrocatalytic oxygen evolution reaction (OER) performances. In 1 M KOH solution, the as-obtained CoNiFe-HHTP merely required 209 mV overpotential to deliver a current density of 10 mA cm -2 , with a low Tafel slope of 36.81 mV dec -1 . Also, the as-obtained CoNiFe-HHTP could stably run more than 240 h at a current density of 10 mA cm -2 , exhibiting superb long-term stability. The present work provides a promising strategy to promote the electrocatalytic activity of cheap transition metal LDH materials for electrochemical water decomposition.