Nanoparticle-Stacked Porous Nickel–Iron Nitride Nanosheet: A Highly Efficient Bifunctional Electrocatalyst for Overall Water Splitting

Nanoparticle-stacked porous Ni3FeN nanosheets were synthesized through a simple nitridation reaction of the corresponding LDHs. The nanosheet is composed of stacked nanoparticles with more active sites exposed for electrocatalytic reactions. Thus, it exhibited excellent oxygen evolution reaction performance having an extremely low overpotential of 223 mV at 10 mA/cm2 and hydrogen evolution reaction property with a very low overpotential of 45 mV at 10 mA/cm2. This electrocatalyst as bifunctional electrodes is used to overall water splitting in alkaline media, showing a high performance with 10 mA/cm2 at a cell voltage of 1.495 V.