Interfacial vapor gradient regulation via enhanced condensation for solar-driven synergistic water-electricity generation

Solar-driven synergistic freshwater and electricity production presents a promising solution to address global water-energy challenges. However, existing systems suffer from limited condensation surface area and long vapor transport paths, which easily lead to vapor accumulation at the evaporation interface and consequently a decrease in evaporation rate. This study develops an integrated thermoelectric-interface evaporation system featuring vapor gradient regulation through enhanced condensation. It lies in a hierarchical condensation architecture with arrayed structures that triple the effective surface area, creating abundant nucleation sites for accelerated vapor phase transition. This structural design effectively reduces the interface vapor saturation and maintains high evaporation flux through dynamic vapor pressure regulation. Under 1 sun irradiation, the system achieves concurrent water production (0.48 kg m −2  h −1 ) and electricity generation (168.15 mV open-circuit voltage). With optical concentration via a Fresnel lens, these performance metrics are further elevated to 0.72 kg m −2  h −1 and 280 mV. Importantly, the device operates stably with various feedwaters, and its practical value is demonstrated by continuously powering mobile communication equipment. This condensation-mediated vapor regulation strategy establishes a new paradigm for high-efficiency synergetic water-electricity generation, particularly for decentralized applications in resource-limited regions.