Nitesh, P.P.NiteshKumar, T. R. NaveenT. R. NaveenKumarSengottaiyan, C.C.SengottaiyanSeetharaman, AmreethaAmreethaSeetharamanThirumurugan, ArunArunThirumuruganKandasamy, ManikandanManikandanKandasamyKavinkumar, T.T.Kavinkumar2026-07-072026-07-072027-01-01FUEL, 427, 139939 (2027). https://doi.org/10.1016/j.fuel.2026.1399390016-23611873-7153https://hdl.handle.net/20.500.12740/24788Designing cost-effective, highly competent, and resilient transition metal-based electrodes has gained significant research interest towards energy storage and conversion. Herein, we present a rational design of a ZnO/CoNi2S4 heterojunction nanoarray electrode by incorporating ZnO nanoflakes with transition metal sulfides to construct a multifunctional hybrid array. Extensive investigations along with theoretical analysis revealed the nano- engineered interfaces promote interfacial charge redistribution, thereby accelerating rapid charge-transfer kinetics. Furthermore, the hetero-hybrid architecture affords ample of electroactive sites and strengthens the synergy created due to interfacial electronic interaction. The redistribution of interfacial electrons between ZnO and CoNi2S4 promotes robust synergistic effects from multimetallic centers, optimizing the overall electronic structure for superior catalytic activity. As a result, the ZnO/CoNi2S4 electrocatalyst delivered small overpotentials of 102.2 mV for HER and 198.7 mV for OER at 10 mA cm- 2, along with excellent long-term stability. The assembled hybrid electrolyzer requires only 1.56 V to achieve 10 mA cm- 2. In addition, this electrode also exhibits an ultrahigh specific capacity of 1319.0C g- 1 at 1 A g-1 and retained over 94% of its value after 15,000 cycles at 10 A g-1. This hybrid supercapattery combination (ZnO/CoNi2S4//activated carbon) achieved a high energy density of 62.7 W h kg-1 at 2100 W kg-1, preserving 84.8% specific capacity retention after prolonged cycling, highlighting its great potential for multifunctional energy storage applications. This study constructs an effective pathway for fabricating progressive electrodes with superior performance.Water electrolysisBifunctional electrocatalystsElectronic configuration tailoringHybrid supercapacitorHeterostructureArticulohttps://doi.org/10.1016/j.fuel.2026.139939