Abstract

Herein, a facile approach for the design of dual high-efficacy supercapacitor electrode and efficient bidirectional electrocatalysts in electrolysis using hierarchical ZnS/CoNi2S4 (ZCNS) heterostructure was developed. Comprehensive experimental analysis unveiled that ZCNS heterostructure underwent a surface reformation, during electrochemical reactions, with an in-situ construction of Ni(OH)2 and Co(OH)2 onto ZnS@CoNi2S4 interface. As a result, the ZCNS heterostructure delivered a large specific capacity of 730.0 C g?1 at 1 A g?1 exhibiting a substantial cyclic stability. Consequently, the fabricated supercapattery device inherited a maximum energy density of 56.1 W h kg?1 at a power density of 2100.1 W kg?1 with a remarkable capacity of 289.0 C g?1 at 3 A g?1. Moreover, ZCNS electrocatalyst was exposed to be an impressive hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalyst, which harvested the current rates of 10 and 50 mA cm?2 under an overpotential of 170.1 mV for HER and 327.6 mV for OER with good durability in 1 M KOH, respectively. Additionally, the fabricated ZCNS||ZCNS device required only a lower potential of 1.61 V to drive a current rate of 10 mA cm?2 for the complete electrolyzing process. © 2025 Elsevier B.V.