Parametric influence on the physical characterizations of covalent organic framework-1

Four samples of covalent organic framework-1 (COF-1) assigned as S1 to S4 were prepared by varying the initial mass of 1,4-benzene diboronic acid (BDBA) used and heating condition. The samples were physically characterized using Brunauer–Emmett–Teller (BET) surface area analysis and FESEM analysis. The BET surface area value showed an increasing trend with increasing mass of BDBA used. The highest achievable BET surface area is recorded by COF-1 (S3) with a value of 107.9 m2/g. The low surface area obtained is likely due to the distribution of particles with large pore sizes. This is confirmed by the Field Emission Scanning Electron Microscopy (FESEM) images which correlate well with the surface area obtained. The presence of dendrites phase within the COF-1 structure also indicates incomplete formation of a crystalline structure, hence contributed to the low surface area achieved. It was also found that the use of ramping heating did not significantly influence the formation of COF-1 crystalline structure which promotes the surface area.