High‐Efficiency Moisture‐Driven Electric Generator Enabled by Hydrophilic 0D Perovskite†

Comprehensive Summary Moisture enabled electric generation (MEG) is an innovative green energy technology that converts the chemical potential energy of atmospheric water vapor into electricity. Here, we report a novel molecular‐level zero‐dimensional (0D) perovskite‐based MEG device that efficiently harvests ambient moisture to generate electric power, which makes perovskite a new kind of potential MEG. The 0D perovskite, DAP₂PbI₆, (where DAP is 1,3‐bis(ammonium)‐2‐hydroxypropane diiodide.) features a unique hydrogen‐bonding network formed between its ammonium (–NH₃ + ) and hydroxyl (–OH) groups, imparting water stability and remarkable hydrophilicity. Such robust interactions facilitate water adsorption and the subsequent release of hydrogen ions under humid conditions. These protonic species establish an ion gradient, driving a directional current via the ion‐gradient diffusion–induced voltage. We demonstrated a maximum volumetric power density of 45 mW·cm –3 —substantially exceeding previously reported values for protein‐ or carbon‐based MEG. Additionally, SEM and AFM analyses confirm DAP₂PbI₆ is stable upon moisture exposure, while temperature‐dependent impedance spectroscopy and theoretical calculations reveal that proton diffusion is the primary mechanism for the observed moisture‐driven electricity. These findings underscore the promise of hydrophilic 0D perovskite materials for high‐efficiency MEG and pave the way for next‐generation sustainable power applications.