Achieving efficient water-electricity ensemble via using easily obtainable hydrovoltaic-thermoelectric hybrid generators

The solar-driven water-electricity cogeneration system (WECS) has emerged as a promising strategy to simultaneously address the global challenges of water scarcity and sustainable energy production. Despite its dramatic potential, current WECS technologies face issues related to complex processes and limited energy output, which hinder their practical application. In this study, we present an efficient WECS utilizing a spray-constructed carbon black/polyvinylidene fluoride loaded bamboo fiber paper (CB/PVDF@BFP) hybrid integrated with double-stacked thermoelectric generators (TEGs). The CB/PVDF@BFP composite features a Janus structure with hydrophobic and hydrophilic sides, facilitating efficient water evaporation and hydrovoltaic electricity generation. Under one sun irradiation, the composite achieves an evaporation rate of ~ 1.41 kg·m⁻²·h⁻¹ with ~ 90 % photothermal efficiency and up to ~ 99.8 % decontamination efficiency for efficient water purification. Notably, our designed hybrid power generation module can reach up to ~ 1600.44 mW/m² under 1 sun, ~ 3-fold and ~ 4000-fold exceeding the previous only thermoelectric- and hydrovoltaic- based devices, respectively. This hybrid approach demonstrates enhanced energy recovery and utilization of solar energy, offering a promising solution to the water and energy crises through a single WECS.