Leaf-like zinc-based porous framework–nickel molybdenum hydroxide materials for integrated energy storage and self-powered systems

Abstract

Multifunctional materials capable of efficiently storing energy while harvesting mechanical energy are central to the development of self-sufficient, self-powered electronic systems. Yet, most reported materials either exhibit limited multifunctionality or rely heavily on device-level integration to achieve dual functionality. In this work, a hierarchically coupled 2D–2D NiMo layered double hydroxide (LDH)/leaf-like Zn-ZIF-L heterostructure is synthesized through a simple in-situ growth approach. The leaf-like Zn-ZIF-L framework provides a porous and mechanically robust scaffold that supports the uniform growth of ultrathin NiMo-LDH nanosheets, effectively suppressing restacking and enabling continuous pathways for ion and charge transport. Owing to this architecture, the optimized NiMo-LDH + ZIF-L0.5g electrode delivers a high specific capacitance of 1326.7 F g􀀀 1, low charge-transfer resistance, and rapid ion transport governed by a mixed capacitive-diffusion process (b ≈ 0.65, with ~79% capacitive contribution). When assembled into a asymmetric supercapacitor with reduced graphene oxide, the device operates stably over a 1.3 V window, achieving an energy density of 22.3 Wh kg􀀀 1 at a power density of 1300 W kg􀀀 1 with excellent cycling durability. Beyond electrochemical storage, the same heterostructure acts as an effective tribo-positive material, generating electrical output of ~600 V, ~270 μA, and a peak power density of 19.36 W m􀀀 2 in a vertical contact-separation mode of triboelectric nanogenerator. Together, these results demonstrate that LDH-MOF 2D heterojunctions can function as intrinsically multifunctional materials, providing a unified materials-level strategy for integrated energy harvesting, storage, and next-generation self-powered systems.