MXene-enhanced paper/hydrogel bilayer moisture-driven generator for long-term energy output

Moisture-driven energy generators (MEGs) represent a renewable energy technology, yet challenges such as environmental humidity dependence and transient power generation behavior hinder their practical applications. Herein, a high-performance bilayer MEG is developed by integrating MXene-impregnated paper with a polyacrylamide (PAM) hydrogel to realize environmental tolerance and sustained power generation. Electronegative MXene and paper with 3D porous structure synergistically facilitate selective transport of positive charge, while the hydrogel serves as a water reservoir to provide a moist environment and migratory ions. The MXene-impregnated paper-hydrogel MEG (MPH-MEG) delivers a maximum open-circuit voltage (V oc ) of 0.537 V and power density of 4.8 μW cm −2 at 40 % relative humidity (RH). Moreover, by replacing water in the hydrogel with sodium lactate, the MXene-impregnated paper-organic hydrogel MEG (MPO-MEG) exhibits enhanced water retention, showing a stable V oc of ∼350 mV for over 7 days, even at 40 % relative humidity (RH). Furthermore, the scalable integration of MPO-MEG units demonstrates practical application for powering commercial timers and LEDs. This work presents a novel and facile strategy for preparing high-performance and environmentally stable MEGs for sustained power generation without the need for an additional humid environment.