ZIF-67/氧化纳米纤维素衍生碳气凝胶的制备及其电化学性能研究OA北大核心CSTPCD

To obtain three-dimensional structured carbon aerogels with excellent electrochemical performance,cobalt oxide/carbon(CoO/C)aerogel derived from ZIF-67/TOCNF was prepared by directional freeze-drying and one-step carbonization,using TEMPO oxidized nanocellulose(TOCNF)as the matrix,adding ZIF-67.Results from scanning electron microscope(SEM)showed that the CoO/C aerogels can keep their original structure of ZIF-67/TOCNF before carbonization;CoO derived from ZIF-67 can be uniformly loaded in the carbon skeleton structure,providing more reaction sites.XRD analysis indicated that the ZIF-67/TOCNF aerogel showed that the diffraction peak of a typical ZIF-67 crystal was close to pure ZIF-67;the diffraction peak attributed to TOCNF was suppressed.Co was obtained via the thermal decomposition of ZIF-67.Co/C composite materials with better crystallinity were obtained by high-temperature carbonization.The test results through Raman spectroscopy indicated that the CoO/C composite material has a high degree of graphitization.The electrochemical test and analysis showed that the double-layer capacitance of CoO/C electrode materials was closely related to their internal three-dimensional pore structure.Compared with other carbonization temperatures(500,600,800℃),when the carbonization temperature was 700 ℃,the CoO/C-700 aerogel electrode material has the optimal electrochemical performance with a specific capacitance of up to 92 F/g(0.5 A/g)and exhibits desirable rate performance and cycle stability.