Preparation And Characterization Of The Multifunctional N-hybrid COFs And Its Electrochemical Performances

Two or three dimensional frameworks can be constructed infinitely throughself-assembly or chemical bonding (hydrogen bonds, coordinate bonds, covalentbonds) from the simple molecular units. Synthesis of novel functional porousmaterials based on these has become a fast-developing branch in the field ofmaterial chemistry for the past decade. Covalent Organic Frameworks (COFs),linked solely by covalent bonds of light elements (C, O, N, B, etc.), exhibit anumber of performances including modifiability, variety, permanent pore structureand outstanding stability (chemical stability and thermal stability). Therefore,COFs have been paying more attention in the field of nano-structural materials,energy and environment.This paper illustrates a series of work focusing on the three leading directionsin the field of covalent organic porous framework materials: The design of thestructure of COFs, the directionally controlled synthesis of COFs, and thefunctionalization of COFs. The applications in electrochemistry of the synthesizedCOFs materials are also been explored. The main research works are as follows:(1) In the aspect of structural design and controllable synthesis of N-hybridCOFs, we choose the small organic molecule,1,3,5-Tricyanobenzene as the basisunit, which can be trimerized to triazine rings in the presence of zinc chloride asthe catalyst. Then p-TCB with frameworks composed of benzene rings and triazinerings are obtained by controllable orientation. The regulate function of the catalystin the synthesis process is also been studied. At400℃,the control of the porediameter, pore volume, specific surface area, channel structure and piledmorphology of p-TCB are realized through adjusting the amount of the catalystused. Infrared Radiation (IR), X-ray Diffraction (XRD), Scanning ElectronMicroscope (SEM), and Transmission Electron Microscopy (TEM) are used tocharacterize the materials with the supplementary of theoretical stimulation.(2) In the aspect of functionalization of the material, p-TCB doped by differentmetals (Al,Fe,Co,Ni,Bi) are synthesized with various novel properties.(3) In the aspect of the electrochemical performance of the materials, differential pulse anodic stripping voltammetry (DPASV) is used to detect Pb2+inaqueous media using the as-prepared material as detector. In the highconcentrations Pb2+solution, the lead ion concentration and current responseintensity has a linear relationship. And after optimization of the condition, the limitof detection has reached10-13M, which is the highest reported so far. Therefore,the materials have high sensitivity for detection of trace heavy metal ions.