A novel covalent organic framework with multiple adsorption sites for removal of Hg2+ and sensitive detection of nitrofural

It is urgent to control serious drug pollution and heavy metal ion pollution. Covalent organic framework (COF) is becoming a promising material for the removal of heavy metal ion and adsorption of organic small molecule because of the designed functional sites, ordered pore channel, high specific surface area and abundant pi electrons. Herein, 2,4,6-triformylphloroglucinol (TFP) and benzene-1,3,5-tricarbohydrazide (BTH) was used to design a stable yet efficient beta-ketoenamine COF (COFTFP-BTH) adsorbent, which would provide multiple adsorption sites of Hg2+ by dense acylhydrazine. The maximum adsorption capacity of COFTFP-BTH toward Hg2+ achieved 909 mg g(-1), coinciding with Langmuir adsorption and pseudo-second-order adsorption kinetic model, with the h value as high as 71.43 mg g(-1) min(-1). COFTFP-BTH was also grown on NH2-carbon nanotubes (CNT) to form a novel COFTFP-BTH@NH2-CNT com-posite for sensitive detection of nitrofural (NF). The NF sensor based on COFTFP-BTH@NH2-CNT showed a low detection limit (3.2 nM) and a wide linear range (9.6 nM-100 mu M). The excellent performances were also attributed to the ordered channels of COFTFP-BTH exposing more adsorption sites of Hg2+ and NF, as well as the good stability of beta-ketoenamine COFTFP-BTH. (C) 2021 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.