Synthesis of flower-like NixFe1−x layered double hydroxides with enhanced oxygen evolution catalysis

Abstract

In this work, the NixFe1-x LDHs (x = 0.25, 0.5, 0.75, 0.8) samples were prepared by hydrothermal method. The morphology of NixFe1-x LDHs can be controlled and porous NixFe1-x LDHs "nanoflowers" were obtained at x = 0.75. The XRD patterns showed that pure NixFe1-x LDHs were produced when the nickel and iron salts were at a fixed ratio. By tuning the conductivity of LDHs, the current density of NixFe1-x LDHs/ acetylene black (AB) obviously increased. The Ni0.75Fe0.25 LDHs/AB showed good OER performance with Tafel slope of 31 mV/dec and low overpotential of 262.2 mV at current density of 20 mA/cm2.