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

Abstract

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.