Self-floating triazine COF monolith to realize concurrent production of freshwater and value-added chemicals across tri-phase interface

Solar-driven production of freshwater and clean energy provides a promising sustainable route to deal with the energy crisis, but their simultaneous conversion in an integrated process presents challenges. Here we introduce an innovative integrated photothermal-photocatalytic platform for solar vapor generation coupled with value-added solid chemical production for the first time. Specifically, three triazine covalent organic frameworks (COFs) are bonded onto a self-floating balsa evaporator to reduce the evaporation enthalpy and improve the device's photosynthetic performance. This optimized device, SVG-COF-1, simultaneously produces freshwater at a rate of 2.82 kg m 2  h −1 and sodium perborate (SPB) at 4580 μmol m 2  h −1 from seawater. The SPB is directly converted from photosynthesizing H₂O₂, thereby fixing solar energy in the form of solid value-added chemicals, allowing easy transportation and mass storage. This system effectively extracts freshwater, generates clean energy, and produces transportable high-value chemicals from seawater using natural sunlight without requiring additional energy input.