Template Synthesis And Properties Of Mesoporous Carbon

As a kind of mesoporous materials with the pore size between 2-50 nm, mesoporous molecular sieves might find a lot of applications in the fields of catalysis, adsorption, sensors and so on, because of their highly ordered pore structures and very large specific surface area. Since the first report about M41S mesoporous materials by the scientists of Mobil Research and Development Corporation, it has been widespread concern by researchers around the world.Ordered mesoporous carbons were synthesized through Evaporation Induced Self-assembly method using phenol formaldehyde (PF) resin as carbon resource and triblock copolymer F127, P123, P123/F127as template. The molecular weight of PF resin obtained form different synthesis temperatures was measured by gel permeation chromatography(GPC) and the resultant mesoporous carbon material was characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM) and N2 adsorption/desorption. The effects of different templates, synthesis temperature of PF resin, different solvents, stirring time, solvent evaporation rate, solution PH value and adding of titanium dioxide on the pore size and orderliness of mesoporous carbon were studied. The results show that, template P123/F127 is helpful to prepare carbons with well-ordered hexagonal mesostructure. Mesopore volume and specific surface area were increased by 50% and 33% respectively. when synthesis temperature of PF resin is 85℃, and the weight ratio of P123 to F127 is 1:3, ethanol as solvent, PH value of 7.0, the stirring time 1h, the resultant mesoporous carbon has a well-ordered hexagonal meso-structure, and the BET specific surface area of which is 498.5m2/g with mesopore volume of 0.173 cm3/g, mesoproe surface area of 167m2/g and average pore size of 3.41 nm.Electrochemical performance of mesoproe materials as electrodes of super capacitors were characterized by galvanostatic measurements, cyclic voltammograms and AC impedance spectrum analysis. The electrode performances show that mesoporous materials exhibit the ideal behavior of the double-layer capacitance. Electrode of mesoporous carbon, which was prepared from composite template, has lower impedance and larger capacity, and is suitable for large current density charge/discharge The specific capacitance can reach 166F/g at the current density of 300mA/g,which were increased by 17%.