3D hierarchical ZnCo2S4@Ni(OH)2 nanowire arrays with excellent flexible energy storage and electrocatalytic performance

[Display omitted] •We first synthesized a 3D ZnCo2S4@Ni(OH)2 nanowire arrays on Ni foam.•The introduction of Ni(OH)2 and sulfur element greatly enhances the electrochemical performance.•The ZnCo2S4@Ni(OH)2 // AC ASCs device shows high energy density and power density.•The ZnCo2S4@Ni(OH)2 // ZnCo2S4@Ni(OH)2 water splitting device exhibits low cell voltage. It is essential for energy storage and conversion systems to construct electrodes and electrocatalysts with superior performance. In this work, ZnCo2S4@Ni(OH)2 nanowire arrays are synthesized on nickel foam by hydrothermal methods. As a supercapacitor electrode, the ZnCo2S4@Ni(OH)2 structure exhibits a specific capacitance of 1,263.0C g−1 at 1 A g−1. The as-fabricated ZnCo2S4@Ni(OH)2//active carbon device can achieve a maximum energy density of 115.4 Wh kg−1 at a power density of 5,400 W kg−1. As electrocatalysts, the ZnCo2S4@Ni(OH)2 structure delivers outstanding performance for oxygen evolution reaction (an overpotential of 256.3 mV at 50 mA cm−2), hydrogen evolution reaction (141.7 mV at 10 mA cm−2), overall water splitting (the cell voltage of 1.53 V at 50 mA cm−2), and a high stability for 13 h.