3D nickel molybdenum oxyselenide (Ni1-xMoxOSe) nanoarchitectures as advanced multifunctional catalyst for Zn-air batteries and water splitting

[Display omitted] •3D Ni1―xMoxOSe with numerous oxygen vacancies is successfully developed.•Ni0.5Mo0.5OSe exhibits superior multifunctional activities for ORR, OER, and HER.•Flexible QSS-ZAB reveals ultrahigh peak power density and ultra-long cycle life.•Water electrolyzer entails the ultralow cell voltage of 1.51 V to obtain 10 mA cm−2.•Water electrolyzer is successfully driven by series-connected flexible QSS-ZABs. Rational design of 3D nickel molybdenum oxyselenide (Ni1-xMoxOSe) nanoarchitectures with numerous oxygen vacancies is developed through facile and low-cost hydrothermal and followed by selenium ion modulation approach. The experimental and theoretical studies reveal that the optimal Ni0.5Mo0.5OSe possesses ultrafast charge-transfer kinetics, which would boost the catalytic activities, enhance the accessibility of electroactive sites, and increase the diffusion networks for oxygen species. Most impressively, the optimal Ni0.5Mo0.5OSe affords superior trifunctional activities, outperforming benchmark Pt/C and IrO2 catalysts. When employed as an air-cathode in flexible Zn-air batteries, it achieves a peak power density of 166.7 mW cm−2 and outstanding durability for 300 h in ambient air. Furthermore, the water electrolyzer realizes a current density of 10 mA cm−2 at a cell voltage of 1.51 V, outperforming benchmark Pt/C||IrO2 couple and reported state-of-the-art catalysts. This consequence provides a general strategy to explore highly efficient multifunctional catalysts with enhanced durability.