Water and Electricity Generation with Heterogeneous Hydrogels from Atmosphere and Sunlight

ABSTRACT To solve the thermodynamic inefficiencies caused by waste heat in solar evaporators and the constant problem of salt leakage in hydrogel‐based atmospheric water harvesters, this study puts forward a monolithic system for simultaneous water and electricity generation. We developed a mechanically interlocked interface between laser‐induced graphene (LIG) and a nanocellulose‐reinforced hydrogel. By investigating topology—dependent moisture transport, we found that a full‐coverage LIG pattern is better than edge or middle designs because it gets rid of localized bottlenecks and ensures uniform hydration. Consequently, the optimized system has an outstanding water absorption of 2.57 g g −1 at 60% relative humidity and a sustained thermoelectric power density of 2.25 W m −2 under 1 kW m −2 solar irradiation. To prove practical viability, we incorporated the system into a custom‐built solar‐tracking robotic platform and showed stable, continuous generation under changing outdoor conditions. Finally, this work gives a facile technological framework for getting energy from hygroscopic materials, bridging the gap between advanced interfacial engineering and sustainable, integrated water‐solar‐energy systems.