Preparation Of MOFs/COFs-based Composites And Study On The Electrical Sensing Properties Of Amine Molecules

Porous organic framework materials（MOFs and COFs）have unexceptionable application capacity in chemical sensors.Nonetheless,the applications in the field of electrical sensing are still in their preliminary stage.This paper chiefly studies the electrochemical sensing property of MOFs/COFs chemically decorative electrode materials for amine molecules.（1）Porous covalent organic frameworks（DQ-COF）with redox activity was successfully manufactured by acyl monomer and applied for the removal and detection of hydrazine.DQ-COF adsorbent has a formidable removal capacity for hydrazine,and follows the Friedrich and pseudo-second-order kinetic models,with a maximum removal capacity of 1108 mg g^-1.Meanwhile,DQ-COF loaded on a porous Ni substrate demonstrates distinguished electrochemical performance,which is efficiently responsive to hydrazine at a part per billion（ppb）level,coupled with a wide linear range（0.5～1223μM）,low detection limit（0.07μM）and high anti-interference ability.（2）A novel composite material,hybrid zeolitic imidazolate framework（HZIF）–conducting poly（3,4-ethylenedioxythiophene）（PEDOT）has been fabricated on carbon cloth electrode（CCE）by microwave-assisted crystallization,followed by drop-coating and vapor deposition procedures.The composite sensor（HZIF-Mo/PEDOT/CCE）shows a low detection limit of 0.04μM（S/N=3）for hydroxylamine,a wide linear range（0.1～696.2μM）and outstanding reproducibility（RSD=4.43%）.As noticed,the hydroxylamine catalytic process combines the advantages of the alkaline-stable HZIF-Mo containing ample catalytic sites and high surface area and the mesoporous PEDOT reining in outstanding conductivity and redox capability,thereby imparting amplified electrochemical signals.（3）A simple one-step agitating method to prepare a original ternary heterojunction（ZIF-C/g-C₃N₄/rGO）with 2D/2D/2D structure,in which the small size of ZIF-C nanosheets helps to boost the immobility and the exposure of the active site,while the addition of g-C₃N₄ and rGO conquer the problems of conductivity and charge separation of MOF materials.The ternary composite sensor has a low detection line（0.032μM）,a wide detection range（0.1～1038.6μM）and preeminent stability for hydrazine,and the reproducibility in actual samples is 4.82%.This work provides an opportunity to expand the application of 2D-based ternary heterojunction sensing.