Ternary NiMoCo alloys and fluffy carbon nanotubes grown on ZIF-67-derived polyhedral carbon frameworks as bifunctional electrocatalyst for efficient and stable overall water splitting

•Ternary NiMoCo alloys and fluffy carbon nanotubes grown on ZIF-67-derived polyhedral carbon frameworks.•Evaporated Ni(DMG)2 provides favorable reduction atmosphere for alloy formation during pyrolysis.•The synergistic effect of NiMoCo ternary alloy and fluffy carbon nanotubes contributes to high catalytic performance.•ZIF-67DC/NiMoCo/CNT catalysts display outstanding catalytic performance for HER and OER.•The cell voltage required for water splitting was found to be ∼1.64 V at 10 mA cm−2 in alkaline medium. The synthesis of efficient and stable non-precious metal electrocatalytic materials is one of the main challenges in current overall water splitting research. Herein, this paper puts forward a facile pyrolysis synthesis strategy for the construction of ZIF-67DC/NiMoCo/CNT ternary alloy catalyst with three-dimensional nanostructure and abundant fluffy carbon nanotubes. Benefiting from the synergistic effect between NiMoCo ternary alloy and carbon nanotubes, the ZIF-67DC/NiMoCo/CNT bifunctional catalyst can yield current density of 10 mA cm−2 at overpotentials of 85 mV and 306 mV over HER and OER in alkaline medium, respectively. The overall water splitting device can deliver current densities of 10 mA cm−2 for long periods of time at drive voltages as low as 1.64 V with nearly negligible decay in potential. This study provides a novel and operable method for the design of non-precious metal electrocatalysts. [Display omitted]