A Zn-salen based covalent triazine framework as a promising candidate for CO^sub 2^ capture

A Zn-salen based covalent triazine framework (Zn@CTF) was prepared through ZnCl2 promoted one-pot procedure under ionothermal conditions using salen type precursor N,N′-Bis(5-cyano-salicylidene)-1,2-benzendiamine derived from imine condensation reaction of 3-formyl-4-hydroxybenzonitrile and 1,2-diaminebenzene. The chemical structure of the obtained polymer was characterized by solid-state 13C nuclear magnetic resonance (NMR), fourier transform infrared (FT-IR), energy dispersive spectrometer (EDS) and element analysis. Powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA) showed that the prepared polymer possessed amorphous structure and good thermal stability. The porous property of the polymer material was also characterized by N2 adsorption/desorption isotherm and the Zn@CTF material exhibited excellent porosity with a Brunauer-Emmett-Teller (BET) surface area of up to 598.2 m2 g−1. The surface microstructure property was evaculated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The CO2 adsorption performance of the Zn@CTF was further investigated and it was found that the CO2 uptake capacity was 43.9 cm3 g−1 at 273 K.