Anion‐Counterion Strategy toward Organic Cocrystal Engineering for Near‐Infrared Photothermal Conversion and Solar‐Driven Water Evaporation

Abstract

An anion‐counterion strategy is proposed to construct organic mono‐radical charge‐transfer cocrystals for near‐infrared photothermal conversion and solar‐driven water evaporation. Ionic compounds with halogen anions as the counterions serve as electron donors, providing the necessary electrons for efficient charge transfer with unchanged skeleton atoms and structures as well as the broad red‐shifted absorption (200‐2000nm) and unprecedented photothermal conversion efficiency (~90.5%@808nm) for the cocrystals. Based on these cocrystals, an excellent solar‐driven interfacial water evaporation rate up to 6.1±1.1 kg·m−2·h−1 under 1 sun is recorded due to the comprehensive evaporation effect from the cocrystal loading in polyurethane foams and chimney addition, such performance is superior to the reported results on charge‐transfer cocrystals or other materials for solar‐driven interfacial evaporation. This prototype exhibits the great potential of cocrystals prepared by the one‐step mechanochemistry method in practical large‐scale seawater desalination applications.

Highly efficient NIR-II photothermal conversion from a 2,2′-biquinoline-4,4′-dicarboxylate-based photochromic complex

“…Near-infrared (NIR) photothermal materials are capable of converting absorbed near-infrared light into thermal energy through a non-radiative transition, 1,2 garnering significant attention across various fields including photothermal therapy, 3,4 imaging, 5,6 photo-thermo-electric conversion, 7 seawater desalination, 8,9 and photothermal catalysis. 10 NIR light, spanning from 750 nm to 1700 nm, is commonly classified into NIR-I (750–1000 nm) and NIR-II (1000–1700 nm).…”