(185o) Effects of Physicochemical Properties of Carbon-Based Micro/Nanomaterials on Hydrovoltaic Power Generation in Ionic Aqueous Solution

Hydrovoltaics, generating electrical power via channeling an ionic solution through a hydrophilic micro/nanoporous platform, has recently garnered attention as a promising sustainable energy harvesting technology. Since the hydrovoltaic output has been reported to be affected by electrokinetic phenomena at the solution-channel interface, resulting from surface charge, and porosity of channels, a library of carbon-based nanomaterials that can induce key properties has emerged as feasible candidates.

However, a comprehensive understanding of the relationship between the physicochemical properties of carbon materials and the electricity generation mechanism remains elusive. To move beyond the exploration of random materials, it is crucial to investigate how engineering the surface properties of carbon nanomaterials influences the energy generation mechanism in hydrovoltaic devices.

In this study, we fabricated hydrovoltaic devices using cellulose-based material and porous carbon black nanoparticles. Starting with 20 μm pores of cellulose membrane in a 1M NaCl solution, generating 0.4 V, we controlled the surface charge of microchannels by inducing functional groups to carbon black particles to assess charge density dependence. The experiments revealed that variations in pore size significantly impact voltage generation by affecting ion-channel interfacial interaction that stems from surface charge density and electric double layer within the channels. This work highlights the importance of engineering the physicochemical surface properties of carbon nanomaterials and micro/nanochannel structures in hydrovoltaic substrates for performance optimization.