Large-scale industrial application of electrochemical water splitting calls for remarkable non-noble metal electrocatalysts. Herein, we report on the synthesis of a NiMo-alloy hollow nanorod array supported on Ti mesh (NiMo HNRs/TiM) using a template-assisted electrodeposition method. The NiMo HNRs/TiM behaves as a durable efficient oxygen evolution anode with 10 mA cm⁻² at an overpotential of 310 mV in 1.0 M KOH. Coupled with its superior catalytic performance for hydrogen evolution with 10 mA cm⁻² at an overpotential of 92 mV, we made an alkaline electrolyzer using this bifunctional electrode with 10 mA cm⁻² at a cell voltage of 1.64 V.