Ni-Mo based mixed-phase polyionic compounds nanorod arrays on nickel foam as advanced bifunctional electrocatalysts for water splitting

[Display omitted] •Ni-Mo based nanorod arrays (NMNAs) were prepared by a one-step molten salt strategy.•This nanostructure favor the migration of bubbles and exposing more active sites.•NMNAs exhibit outstanding OER, HER, and overall water splitting activity.•The modulated electronic structures between Ni-Mo contribute to the high activity. The exploration of low-cost, high-efficient and robust bifunctional electrocatalysts for water splitting is urgently desired for developing clean hydrogen energy conversion technology. In this work, we present a facile and effective one-step molten salt synthesis tactics to prepare self-supported 1D Ni-Mo based mixed-phase polyionic compounds nanorod arrays (NMNAs). Due to the exposed more active sites of this nanostructure and accelerated charge transfer derived from modulated electronic structures between Ni-Mo, the as-fabricated NMNAs electrodes deliver remarkable bifunctional electrocatalytic water splitting performance, with overpotential values of 234.2 mV at 200 mA cm−2 and 191.2 mV at 100 mA cm−2 in 1 M KOH for OER and HER, respectively. Furthermore, the alkaline electrolyzer composed of NMNAs needs a low overall-water-splitting cell voltage of 1.423 V to drive a current density of 10 mA cm−2. This work will shed light on the preparation of other related self-supporting nanostructured bifunctional electrocatalysts with excellent performance.