Streaming-Induced Hydrovoltaic Power Generation by Fluorinated Mg–Al Hydrotalcite Nanoclay

Abstract

The rapid growth of hydrovoltaic technologies by scavenging renewable energy sources for power generation provides a promising approach for self-powered devices. In the recent literature, layered double hydroxides have not been explored much, even though they can be a potential candidate for both energy storage and harvesting applications. Herein, we report the fabrication of 2D and 3D hydrovoltaic devices using bare and fluorine-incorporated Mg−Al hydrotalcite nanosized clay. Upon incorporation of fluorine in Mg−Al hydrotalcite, the induced surface charge within the hydrotalcite layer increases, resulting in an enhancement in hydrovoltaic power generation. In this work, we showcase 2D devices that can generate a continuous open circuit potential of 401 mV and a short circuit current of 4.22 μA and a 3D device that can generate a continuous open circuit potential of 603 mV and a short circuit current of 14 μA under ambient conditions. Replacing 2D lateral devices with 3D pellet mode devices could enhance the power output. Another noteworthy aspect of this work is the lower-dimensional area of 3D pellet devices. We fabricated a prototype in which water is dropped from the top side of the device, which is quite different from conventional hydrovoltaic devices. A single droplet can attain a higher output and successfully power up low-power electronic devices.