Self-Supporting NiFe Layered Double Hydroxide “Nanoflower” Cluster Anode Electrode for an Efficient Alkaline Anion Exchange Membrane Water Electrolyzer

Abstract

The development of an efficient and durable oxygen evolution reaction (OER) electrode is needed to solve the bottleneck in the application of an anion exchange membrane water electrolyzer (AEMWE). In this work, the self-supporting NiFe layered double hydroxides (NiFe LDHs) “nanoflower” cluster OER electrode directly grown on the surface of nickel fiber felt (Ni fiber) was synthesized by a one-step impregnation at ambient pressure and temperature. The self-supporting NiFe LDHs/Ni fiber electrode showed excellent activity and stability in a three-electrode system and as the anode of AEMWE. In a three-electrode system, the NiFe LDHs/Ni fiber electrode showed excellent OER performance with an overpotential of 208 mV at a current density of 10 mA cm−2 in 1 M KOH. The NiFe LDHs/Ni fiber electrode was used as the anode of the AEMWE, showing high cell performance with a current density of 0.5 A cm−2 at 1.68 V and a stability test for 200 h in 1 M KOH at 70 °C. The electrocatalytic performance of NiFe LDHs/Ni fiber electrode is due to the special morphological structure of “nanoflower” cluster petals stretching outward to produce the “tip effect,” which is beneficial for the exposure of active sites at the edge and mass transfer under high current density. The experimental results show that the NiFe LDHs/Ni fiber electrode synthesized by the one-step impregnation method has the advantages of good activity and low cost, and it is promising for industrial application.