Synergistic Solar-Mechanical Energy Harvesting in Covalent Organic Framework–Piezoelectric Aerogel Hybrid Evaporator for Efficient Seawater Desalination

Interfacial solar vapor generation holds promise for sustainable desalination yet is often constrained by low photothermal efficiency and slow evaporation kinetics. Here, we introduce a hybrid evaporation system by integrating hydrophilic porphyrin covalent organic frameworks (Por-COFs) with a piezoelectric aerogel. The Por-COFs, constructed from porphyrin (donor) and thiadiazole (acceptor) units, exhibit ordered nanopores that promote the formation of water clusters, effectively reducing the energy required for evaporation. Simultaneously, the piezoelectric aerogel, featuring vertically aligned channels, harvests low-frequency wave energy to generate an electric field, which narrows the bandgap of Por-COFs and activates the adjacent water molecules. The synergistic effect of photothermal conversion of Por-COFs and piezoelectric water activation contributes to a high evaporation rate of 2.82 ± 0.3 kg m–2 h–1 under 1-sun illumination, offering promising prospects for efficient solar thermal energy conversion.