One-pot synthesis of highly porous nitrogen and oxygen codoped carbons for solar-driven atmosphere water harvesting

Abstract

There is significant interest in developing high-performance adsorbents that can harvest water from atmospheric air powered by sunlight. However, The inherent hydrophobicity of porous carbon limits water harvesting capacity. Herein, we report a new class of activated porous carbons (PAK-21) with high water adsorption capacity at moderate to high humidity by solid-phase polymerization of terephthalaldehyde and 2,6-diaminopurine in the presence of KOH under an argon atmosphere at 150 °C for 2 h, and then activated at a high temperature of 700 °C for 1 h. The water harvesting performance surpasses the most common MOFs and porous carbon adsorbents, which benefit from rich surface heterogeneity and highly porous structure. PAK-21 also exhibits fast solar-driven desorption kinetics, ascribing to rapid photothermal responsiveness, hierarchical porosity, and suitable hydrophilicity. Besides, twenty-one adsorption-desorption cycles have been performed to demonstrate its easy regeneration and long-term cyclability. This may pave a new way to modulate the surface functionality and microporous/mesoporous engineering of carbon adsorbents for high-performance solar-driven AWH.