Covalent organic frameworks functionalized carbon fiber paper for the capture and detection of hydroxyl radical in the atmosphere

摘要

Developing a fast,sensitive and convenient method for the detection of hydroxyl radicals(·OH) in the atmosphere could help us know the precursor levels of atmospheric species and control air pollution.In this work,the carbon fiber paper(CFP) functionalizing with a kind of covalent organic frameworks(COFs),formed from 1,3,5-triformylphloroglucinol(Tp) and benzidine(BD)(COF(TpBD)),was firstly used a new platform for ·OH trapping and detection.The COF(TpBD) modified CFP was acted as a filter to impregnate salicylic acid(SA) and a detector to detect 2,5-dihydroxybenzoic acid(2,5-DHBA) which was produced from the reaction between the impregnated SA and ’OH in the atmosphere.This method provided a linearity for 2,5-DHBA from 5.0×10^-14 mol/L 1.0×10^-9 mol/L with a detection limit of 6.9×10^-15 mol/L,which is corresponding to the amount of ·OH from 3.0×10^7 to 6.0×10^11 molecules/cm3 with the detection limit of 4.1×10^6 molecules/cm3.This COF(TpBD)-CFP platform has been successfully applied for the detection of ·OH concentration under different conditions of Yangzhou when the sampling time was shortened to 30 min.This work has provided a new method for atmospheric·OH detection with excellent sensitivity,simplicity,and high speed.