Hydrovoltaic electricity generator using a hierarchical NiFe LDH-coated CuO nanowire mesh device

Abstract

Innovative advancements in sustainable water-energy nexus solutions are paramount in the current global context. This study introduces a hydrovoltaic electricity generator with advanced capillary wicking under ambient conditions. A hierarchical nanostructure of nickel–iron layered double hydroxides (NiFe LDHs) was deposited on copper oxide nanowires (CuO NWs) on Cu meshes to enhance the diffusion of ion-rich water. The LDH coating improves the overall power, voltage, and robustness of the device. A 200 µL droplet of hygroscopic solutions on a device produces electricity at 0.2 V scale, one of which could be sustained for over 140 h. We explored the working mechanisms, parametric studies, and potential scalability through serial allocation for further applications. This study allows water-driven electricity generation using hierarchical nanostructured materials, effectively harnessing renewable energy from readily available hygroscopic salts or abundant seawater resources.