Self-powered graphene-based composites for rain energy harvesting

Harnessing waste green energy utilizing advanced energy conversion technologies is widely considered a promising avenue for enhancing the power generation capacity of renewable energy. In this study, we present the experimental realization of a tailored energy conversion device using graphene-carbon black/polyvinyl chloride (G-CB/PVC) composite films for the innovative harvesting of rainwater energy. Based on the cyclic charge–discharge behaviors of electron/cationic pseudocapacitance at the film–raindrop interface, periodic current and voltage signals were generated with maximum values exceeding 2.5 μA and 100 μV per droplet by optimizing the concentrations and species of cations, respectively. Electricity outputs were significantly enhanced by increasing the electron concentration in the composite films. It is noteworthy that rainwater energy-harvesting devices exhibit exceptional long-term stability, enduring persistent attacks posed by continuous simulated rainfall conditions.