Low-Cost Corncob Carbon-Based Cogeneration of Freshwater and Electricity via Interfacial Photothermal-Thermoelectric Integration

Addressing the pressing issue of global freshwater scarcity through interfacial solar desalination necessitates the implementation of sophisticated thermal management methodologies. This research introduces a waste-derived hybrid photothermal-thermoelectric cogeneration apparatus characterized by three structural advancements: (1) A phase-separated dual-zone configuration that separates solar absorption from condensation regions, thereby facilitating concurrent latent heat recovery via thermoelectric generators; (2) Multifunctional surface engineering that integrates antifog optical coatings with biomimetic microgrooves; (3) Synergistic integration with solar air collectors that amplifies thermal convection, as substantiated by ANSYS Fluent multiphase simulations. The carbonized corncob, subjected to optimization through controlled carbonation at varied temperatures, exhibits remarkable broadband absorption properties and rapid capillary transport capabilities, achieving unprecedented evaporation rates of 1.91 kg/(m2·h) under a solar intensity of 1 sun. Field evaluations reveal a dual-output performance: 22.5 L/(m2·day) freshwater production, which fulfills the daily requirements for approximately 11 individuals in accordance with WHO standards, alongside a power density of 31.39 W/m2 during peak noon conditions. Computational fluid dynamics simulations indicate improved vapor-latent heat utilization through directed phase change pathways, resulting in a temperature increase of 4.5 °C and a corresponding enhancement in power generation of 27.7–34.6 μA. The findings suggest that the device is poised to enhance energy conversion efficiency and broaden the applicability of solar-powered seawater desalination systems.