Light–Moisture Coupling for Enhanced Energy Harvesting

Moisture electricity generators (MEGs) offer a promising route for harvesting energy from ambient humidity, yet their long‐term operation is fundamentally limited by ion‐concentration‐gradient saturation, which induces reverse potential formation and performance decay. Recently, a photon‐assisted moisture electricity generator that overcomes this bottleneck through a light–moisture coupling strategy is reported. By integrating a photosensitive layer with a proton‐transport hydrogel and a moisture‐adsorbing layer, photogenerated carriers continuously consume accumulated protons under illumination, dynamically reconstructing the ion concentration gradient during operation. This mechanism enables a transition from transient output to long‐term steady‐state power generation, achieving more than a threefold increase in power density. Beyond improving device performance, this work establishes a general framework for actively regulating ion gradients in hydrovoltaic systems and points toward sustainable, nonsacrificial strategies for next‐generation MEGs.