Enhancing hydrovoltaic power generation with carbon spheres coated on nickel foam/polyethylene terephthalate substrate

The present study aims to assess the viability of hydrovoltaic impact as a potential method for energy generation. This methodology utilizes the capillary action of water in devices composed of nickel (Ni) foam/polyethylene terephthalate (PET) substrates coated with hydrothermally synthesized carbon spheres at various temperatures (180, 200, and 220 °C). The prepared materials and devices were analyzed using a range of analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR). The SEM images revealed the spherical morphology of the carbon particles and their presence on Ni foam, whereas the XRD patterns indicated that the carbon spheres were amorphous. Spectroscopic analysis revealed the presence of hydroxyl functional groups in all the samples. The performance of the devices was assessed by electrochemical tests, including open-circuit potential (OCP), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The device coated with carbon spheres synthesized at 180 °C demonstrated enhanced performance with an elevated OCP value of 0.077 V, increased surface charge area, lower resistance to water, and reduced charge transfer resistance. These findings indicate the successful production of hydrovoltaic energy by utilizing the capillary action of water in carbon-sphere-coated Ni foam/PET devices.