Aqueous Processable Two‐Dimensional Triazine Polymers with Superior Photocatalytic Properties

Abstract Efficient and scalable production of high‐quality and processable two‐dimensional (2D) polymers are highly desired but have not yet been reported. Herein, we demonstrate a convenient noncovalent functionalization strategy for producing highly uniform, aqueous processable and semiconducting 2D triazine polymers. Experimental and theoretical analysis reveal that the aromatic amphiphilic 1‐pyrenebutyrate can adsorb and intercalate into the interlayer of bulk crystalline covalent triazine framework (CTF) through noncovalent π‐π stacking interaction between the pyrene moiety and the porous basal plane of 2D triazine polymer layer, which greatly facilitate the exfoliation of CTF in water in large scale. The as‐prepared highly water‐dispersible single‐layer/few‐layer 2D triazine polymer nanosheets can be easily processed into ultralight aerogels with a density of 5–15 mg cm −3 , which can be further shaped into mechanically strong films upon simple compression. This noncovalent functionalization not only improve the dispersibility and processability of 2D triazine polymer, but also optimize its band structure and promote the photogenerated carrier separation via an interesting surface molecule doping effect, thus resulting in a remarkable photocatalytic hydrogen evolution rate of 1249 μmol h −1 (24980 μmol g −1 h −1 ) and apparent quantum efficiency up to 27.2 % at 420 nm for the 2D triazine polymer, outperforming most metal‐free photocatalysts ever reported.