Functionalized MIL-125(Ti)-based high-performance triboelectric nanogenerators for hygiene monitoring

Abstract

Metal-organic frameworks (MOFs) have emerged as promising materials for energy harvesting through triboelectric nanogenerators (TENGs). Strategic incorporation of functional groups within the MOFs offers a method for tailoring the surface and functional properties of composite materials, thus leading to enhancement in the performance of TENGs. This study investigates the relationship between functional groups and TENG performance using MIL-125(Ti), specifically incorporating electron-donating (NH2) and electron-withdrawing (NO2) groups. MIL-125(Ti)-NH2@silicone composite film, along with aluminum, produces a maximum voltage and current of 512 V and 130 μA, and a power density of 6.75 W m−2, which is twice the power density of the pure silicone-based TENG. The enhancement of TENG output is attributed to the functionalization of MIL-125, which results in the change of dielectric constant, work function and tuning of the band gap of the composite materials. Furthermore, a novel TENG-based door sensor was demonstrated for the application of a smart alert hygiene system. This sensor efficiently tracks the number of washroom usages by detecting door movements. The real-time data generated by the system notifies the cleaning staff, ensuring the maintenance of a cleaner and more hygienic washroom environment. The study highlights the potential of functionalized MIL-125(Ti)-based TENGs for efficient energy harvesting and sustainable hygiene monitoring. © 2025 RSC.