Nickel Molybdenum Nitride Nanorods Grown on Ni Foam as Efficient and Stable Bifunctional Electrocatalysts for Overall Water Splitting

Non-noble-metal electrocatalysts for water splitting hold great promises for developing sustainable and clean energy sources. Herein, a highly efficient bifunctional electrode consisting of Ni-doped molybdenum nitride nanorods on Ni foam is prepared through topotactic transformation of NiMoO4 nanorods that are in situ hydrothermally grown on Ni foam. The electrode not only contains rich, accessible, electrochemically active sites but also possesses extraordinary chemical stability. It exhibits excellent hydrogen evolution reaction and oxygen evolution reaction performance in 1.0 M KOH with low overpotentials of 15 and 218 mV, respectively, at a current density of 10 mA cm–2, superior to the commercial benchmark materials Pt/C and RuO2 under the same condition. A simple water electrolyzer using the obtained electrode as both the anode and cathode needs a very low cell potential of 1.49 V to reach a current density of 10 mA cm–2 and maintains stability for 110 h without degradation. The excellent performanc...