NiFe Layered Double Hydroxide Nanosheets Anchored on Cobalt Nanocrystal Matrixes as Electrocatalysts for Oxygen Evolution

One crucial pattern to vigorously develop renewable energy is to exploit high-performance oxygen evolution reaction (OER) electrocatalysts. Therefore, we constructed a nanoscale heterogeneous structure catalyst, NiFe-LDH/Co-NC (LDH = layered double hydroxide; Co-NC cobalt nanocrystal), consisting of ultrasmall NiFe-LDH nanosheets and Co-NC matrixes carbonized from ZIF-67. In 1 M KOH, NiFe-LDH/Co-NC-2 requires only an overpotential of 282 mV to catalyze a current density of 10 mA cm–2 and also has a Tafel slope of 64 mV dec–1, surpassing those of the typical OER electrocatalyst RuO2. Co-NC was able to supply a porous structure and anchoring sites, including improving the electrical conductivity of NiFe-LDH. Modified NiFe-LDH has a highly dispersed nature and therefore exposes more active sites. Moreover, the accelerated electron-transfer process caused by strong interaction between NiFe-LDH and Co-NC dramatically optimized the energy barrier of the OER. This work provides significant guidelines to design a high-performance OER of NiFe-LDH catalysts.