Design and Construction of an Azo-Functionalized POP for Reversibly Stimuli-Responsive CO(2) Adsorption

A porous azo-functionalized organic polymer (JJU-2) was designed and prepared via oxidative coupling polymerization promoted by FeCl(3). JJU-2 exhibited reversibly stimuli-responsive CO(2) adsorption properties as a result of the trans/cis isomerization of the polymer’s azo-functionalized skeleton. Under UV irradiation and heat treatment, this porous material displayed various porous structures and CO(2) adsorption properties. The initial Brunauer-Emmett-Teller (BET) surface area of JJU-1 is 888 m(2) g(−1). After UV irradiation, the BET surface area decreases to 864 m(2) g(−1), along with the decrease of micropores around 0.50 nm and 1.27 nm during the trans-to-cis isomerization process. In addition, CO(2) sorption isotherms demonstrate an 8%t decrease, and the calculated Qst of CO(2) has decreased from 29.0 kJ mol(−1) to 26.5 kJ mol(−1) due to the trans to cis conversion of the azobenzene side group. It is noteworthy that JJU-2′s CO(2) uptakes are nearly constant over three cycles of alternating external stimuli. Therefore, this azo-functionalized porous material was a potential carbon capture material that was responsive to stimuli.