Interfacial Engineering of MXene-Assisted Advanced Coaxial Nanofibers for High-Performance Energy Harvesters.
Abstract
Multiferroic magnetoelectric composites are a class of materials that exhibit the magnetoelectric effect, providing a sustainable alternative to batteries for Internet of Things and 'set-and-forget' electronics. In this study, hybrid coaxial nanofiber composites are engineered via electrospinning to achieve synergistic, multifunctional ME properties. The optimized coaxial nanofiber composite CMSP, comprising a core of PVDF-MXene-MnFe2O4 and a shell of AlN-(PVDF-TrFE), exhibits high β-phase fraction (∼96%), delivering a piezoelectric coefficient of 42.6 pC N-1 alongside a ME coefficient of 122 mV cm-1 Oe-1. Subsequent UV-assisted interfacial modulation of system (CMSPUV) further enhances dipolar alignment and interfacial coupling, yielding an improved piezoelectric response of 53.2 pC N-1 and an elevated ME coefficient of 154 mV cm-1 Oe-1. The CMSPUV-based magneto-mechano-electric (MME) generator demonstrates an open-circuit voltage of 24.5 V, a current output of 6.85 µA, and volumetric DC power density of 7.5 µW cm-3 under low-intensity magnetic excitation (6 Oe, 50 Hz), enabling direct powering of 16 LEDs signboard from ambient electromagnetic noise sources. When operated in mechanical energy-harvesting mode, the same platform delivers a high output of 113.6 V and 37.8 µA, with power density of 560 µW cm-2, sufficient to operate a humidity sensor and illuminate LEDs under gentle mechanical stimuli.