The Polymer Society of Korea

Abstract

We report a humidity-tolerant moisture-driven energy generator based on an ion-selective bilayer structure composed of a porous MXene (Ti₃C₂Tₓ) aerogel and ionic hydrogel. The negatively charged MXene aerogel facilitates preferential cation transport from the hydrogel, forming an internal moisture gradient independent of ambient humidity. The device exhibits a high open-circuit voltage (~600 mV), short-circuit current density (~1160 μA cm⁻²), and power density (~25 μW cm⁻²) over a wide humidity range. DFT calculations confirm the role of MXene pore defects in enhancing directional ion diffusion. The device also demonstrates mechanical flexibility, enabling integration into wearable sensors for motion and expression detection. This work provides a design platform for stable and self-powered nanogenerators in diverse environments.