“Structural instability” induced high-performance NiFe layered double hydroxides as oxygen evolution reaction catalysts for pH-near-neutral borate electrolyte: The role of intercalates

Abstract

The main goal of this research was to develop cost-effective oxygen evolution reaction (OER) catalysts by using environment-friendly pH-near-neutral electrolytes. NiFe layered double hydroxides (LDHs) intercalated with different dicarboxylate anions were tested among which suberate anion intercalated NiFe LDH was found to be a great OER catalyst which outperformed RuO2, especially when the current density was larger than 2 mA cm−2. The suberate anion intercalated NiFe LDH needed an overpotential of 387 mV to reach 1 mA cm−2 which is one of the lowest among all reported non-noble-metal OER catalysts on fluorine-doped tin oxide electrode and an overpotential of 420 mV to achieve 2 mA cm−2 which is much lower than that of RuO2. Moreover, this material showed great stability for at least 24 h. All the NiFe LDHs intercalated with dicarboxylate anions showed good OER performance, which could be attributed to the “structural instability” induced “in-situ anion exchange” process during OER.