The synthesis of highly crystalline covalent triazine frameworks (CTFs) with ultrastrong covalent bonds (aromatic CN) from the triazine linkage presents a great challenge to synthetic chemists. Herein, the synthesis of highly crystalline CTFs via directly controlling the monomer feeding rate is reported. By tuning the feeding rate of monomers, the crystallization process can be readily governed in a controlled manner in an open system. The sample of CTF‐HUST‐HC1 with abundant exposed {001} crystal facets has the better crystallinity and thus is selected to study the effect of high crystallinity on photoelectric properties. Owing to the better separation of photogenerated electron–hole pairs and charge transfer, the obtained highly ordered CTF‐HUST‐HC1 has superior performance in the photocatalytic removal of nitric oxide (NO) than its lesser crystalline counterparts and g‐C3N4.

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Covalent triazine frameworks have recently been demonstrated as promising materials for photocatalytic water splitting and are usually used in the form of suspended powder. From a practical point of view, immobilized CTFs materials are more suitable for large-scale water splitting, owing to their convenient separation and recycling potential. However, existing synthetic approaches mainly result in insoluble and unprocessable powders, which make their future device application a formidable challenge. Herein, we report an aliphatic amine-assisted interfacial polymerization method to obtain free-standing, semicrystalline CTFs film with excellent photoelectric performance. The lateral size of the film was up to 250 cm2, and average thickness can be tuned from 30 to 500 nm. The semicrystalline structure was confirmed by high-resolution transmission electron microscope, powder X-ray diffraction, grazing-incidence wide-angle X-ray scattering, and small-angle X-ray scattering analysis. Intrigued by the good light absorption, crystalline structure, and large lateral size of the film, the film immobilized on a glass support exhibited good photocatalytic hydrogen evolution performance (5.4 mmol h−1 m−2) with the presence of co-catalysts i.e., Pt nanoparticles and was easy to recycle.

Crystalline covalent triazine frameworks (CTFs) have shown intriguing applications in photoelectric fields. So far, a number of synthetic strategies based on homogeneous nucleation have been reported. However, it still remains a great challenge to acquire crystalline CTFs with wide structural diversity. Here, we report the synthesis of crystalline CTFs via a novel heterogeneous nucleation strategy, which exhibits a wide monomer scope. The crystalline CTFs could be successfully induced and grown on the lattice planes of salt, which works as a heterogeneous nucleation agent. The CTFs of different structures were successfully obtained with high degrees of crystallinity and nanosheet morphologies. These crystalline CTFs with structural diversity showed excellent activities in photocatalytic hydrogen evolution from sea water. The highest hydrogen evolution rate from "sea water" reached 791 μmol h −1 with a quantum yield of 12.8% under 420 nm irradiation. This work successfully demonstrated a new approach to synthesize crystalline CTFs with a wide monomer scope for photoelectric applications.

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Internal gelation has been an important sol-gel route for the preparation of spherical microgel for drug delivery, cell therapy, or tissue regeneration. Despite high homogeneity and permeability, the internal gelated microgels often result in weak mechanical stability, unregular interface morphology and low cell survival rate. In this work, we have extensively improved the existing internal gelation approach and core–shell hydrogel microcapsules (200–600 μm) with a smooth surface, high mechanical stability and cell survival rate, are successfully prepared by using internal gelation. A coaxial flow-focusing capillary-assembled microfluidic device was developed for the gelation. Rapid gelling behavior of alginate in the internal gelation makes it suitable for producing well-defined and homogenous alginate hydrogel microstructures that serve as the shell of the microcapsules. 2-[4-(2-Hydroxyethyl)piperazin-1-yl]ethanesulfonic acid (HEPES) was used in the shell stream during the internal gelation. Thus, a high concentration of acid in the oil solution can be used for better crosslinking the alginate while maintaining high cell viability. We further demonstrated that the gelation conditions in our approach were mild enough for encapsulating HepG2 cells and 3T3 fibroblasts without losing their viability and functionality in a co-culture environment.

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A novel efficient method for the synthesis of thiophosphate derivatives catalyzed by methylene blue with blue light irradiation under an air atmosphere is described.