All-Weather-Compatible Hydrovoltaic Cells Based on Al₂O₃ TLC Plates

Electrical power can be extracted from interactions at the interface of water/materials, known as the "hydrovoltaic" phenomenon. Devices based on this emerging technology hold a lot of promise for meeting renewable energy demands, but materials reported to date largely require specific weather conditions, such as low humidity (∼10-30%), thus hindering widespread application. Herein, we report a new use of plates for thin layer chromatography (TLC) that provide a continuous support of capillary-driven water flow. When coated with α-Al₂O₃, this simple 8 cm² device can produce a continuous voltage of ∼0.33 V and a short circuit current of ∼0.85 μA over a wide range of humidity (10-90%). Low cost, stability against surface reactions, ease of fabrication, and power output under varied weather conditions make this device a realistic possibility for use in renewable power generation applications.