Sustainable hydrovoltaic power generation using surface functionalized MWCNT coated cotton strings

Hydrovoltaic energy harvesting systems provide an innovative technology for sustainable electricity generation by utilizing the immense untapped potential of water. Recently reported hydrovoltaic devices provideroutes for power generation using various carbon-based nanomaterials. Hydrovolt work, we present a prototype madaic materials feature surface chemistry, electrical conductivity and tunable interfacial properties. In this work, we present a prototype made of functionalized multi-walled carbon nanotube-based cotton string using a dispersion and dip-coating method. The potential difference is obtained by wetting one end of the device, causing proton accumulation in the region, and creating an electric double layer (EDL) on the surface of functionalized multi-walled carbon nanotube-based cotton string (f-MWCNTs/CS). This prototype delivers an open circuit potential of approximately 0.6 V and a short circuit current of approximately 0.4 µA with only 10 mg active material loading. The wicking property of cotton string demonstrates the ability of f-MWCNTs/CS surface to promote water-induced charge separation and ionic gradient formation. This simple, low-cost and scalable prototype device was also tested for sweat-based power generation, in the future, it can be used to power implanted devices and wearables.