Abstract A binder‐free efficient MoNi 4 /MoO 3‐ x nanorod array electrode with 3D open structure is developed by using Ni foam as both scaffold and Ni source to form NiMoO 4 precursor, followed by subsequent annealing in a reduction atmosphere. It is discovered that the self‐templated conversion of NiMoO 4 into MoNi 4 nanocrystals and MoO 3‐ x as dual active components dramatically boosts the hydrogen evolution reaction (HER) performance. Benefiting from high intrinsic activity, high electrochemical surface area, 3D open network, and improved electron transport, the resulting MoNi 4 /MoO 3‐ x electrode exhibits a remarkable HER activity with extremely low overpotentials of 17 mV at 10 mA cm −2 and 114 mV at 500 mA cm −2 , as well as a superior durability in alkaline medium. The water–alkali electrolyzer using MoNi 4 /MoO 3‐ x as cathode achieves stable overall water splitting with a small cell voltage of 1.6 V at 30 mA cm − 2 . These findings may inspire the exploration of cost‐effective and efficient electrodes by in situ integrating multiple highly active components on 3D platform with open conductive network for practical hydrogen production.

Self‐Templated Fabrication of MoNi4/MoO3‐x Nanorod Arrays with Dual Active Components for Highly Efficient Hydrogen Evolution