Joseph

Covalent triazine frameworks (CTFs) are normally synthesized by ionothermal methods. The harsh synthetic conditions and associated limited structural diversity do not benefit for further development and practical large-scale synthesis of CTFs. Herein we report a new strategy to construct CTFs (CTF-HUSTs) via a polycondensation approach, which allows the synthesis of CTFs under mild conditions from a wide array of building blocks. Interestingly, these CTFs display a layered structure. The CTFs synthesized were also readily scaled up to gram quantities. The CTFs are potential candidates for separations, photocatalysis and for energy storage applications. In particular, CTF-HUSTs are found to be promising photocatalysts for sacrificial photocatalytic hydrogen evolution with a maximum rate of 2647 μmol h⁻¹ g⁻¹ under visible light. We also applied a pyrolyzed form of CTF-HUST-4 as an anode material in a sodium-ion battery achieving an excellent discharge capacity of 467 mAh g⁻¹.

Layered allrounder: A novel polycondensation approach enables the construction of covalent triazine frameworks (CTFs) under mild conditions from a wide array of building blocks. The resulting CTFs present a new type of layered material with potential applications in separations, photocatalysis, and energy storage.

Following removal of coordinated CH₃CN, the resulting complexes [Ag^I(2,2′-bipyridine)][BF₄] (1) and [Ag^I(6,6′-dimethyl-2,2′-bipyridine)][OTf] (2) show ethene/ethane sorption selectivities of 390 and 340, respectively, and corresponding ethene sorption capacities of 2.38 and 2.18 mmol g⁻¹ when tested at an applied gas pressure of 90 kPa and a temperature of (20±1) °C. These ethene/ethane selectivities are 13 times higher than those reported for known solid sorbents for ethene/ethane separation. For 2, ethene sorption reached 90 % of equilibrium capacity within 15 minutes, and this equilibrium capacity was maintained over the three sorption/desorption cycles tested. The rates of ethene sorption were also measured. To our knowledge, these are the first complexes, designed for olefin/paraffin separations, which have open silver(I) sites. The high selectivities arise from these open silver(I) sites and the relatively low molecular surface areas of the complexes.

Site unseen: The coordination complexes 1 and 2, having open silver(I) sites, were prepared and investigated for ethene/ethane binding. These complexes display ethene/ethane selectivity of up to 13 times higher than comparable solid sorbents, ethene loadings of up to 2.38 mmol g⁻¹, and saturation of silver(I) sites of up to 0.96 mol_ethene/mol_silver(I). Tf=trifluoromethanesulfonyl.