Carbazole-decorated covalent triazine frameworks: Novel nonmetal catalysts for carbon dioxide fixation and oxygen reduction reaction

Task-specific carbazole-based covalent triazine frameworks (CTF-CSUs) have been designed and prepared. The obtained materials could serve as excellent catalysts for both CO2 chemical fixation and oxygen reduction reaction (ORR). Results shown that using CTF-CSUs as catalysts, the cycloaddition reactions between CO2 and epoxides were readily achieved with extremely high yields (99%) under mild conditions (0.1 MPa, 25 degrees C). The catalysts could be reused for five times without any obvious loss of catalytic activity. In addition, the as-made carbazole-containing CTFs catalysts delivered attractive ORR activity, superior durability and methanol tolerance relative to commercially available Pt/C reference electrocatalyst (E-TEK). Rich N contents (15.33 wt%) and large surface areas (982 m(2) g(-1)) combining abundant mesopores favor a combination of two-electron and four-electron reduction pathway under alkaline condition. All these attracting characteristics were attributed to their unique structures and strong synergistic effect between carbazole and triazine moieties. (C) 2018 Elsevier Inc. All rights reserved.