Aligned carbon nanotubes(CNTs)were synthesized by nebulized spray pyrolysis of solutions of organometallics in carbon precursor solvents.Four types of straight-chained alkanes including n-pentane,n-hexane,n-heptane and n-octane were used as precursor solvents for synthesis of aligned CNTs.The results from scanning electron microscopy,transmission electron microscopy and Raman spectroscopy show that the CNTs obtained from them have different diameters and degrees of graphitization. It is found that the n-heptane is the most suitable for the growth of aligned CNTs with high quality and yield.The thermodynamic properties of precursory carbon sources such as boiling point and formation enthalpy are considered to play a decisive role in the synthesis of CNTs.It will be very helpful for the controllable preparation of aligned CNTs at relatively low cost.
A high-performance porous carbon material for supercapacitor electrodes was prepared by using a polymer blend method.Phenol-formaldehyde resin and gelatin were used as carbon precursor polymer and pore former polymer,respectively.The blends were carbonized at 800 °C in nitrogen.SEM,BET measurement and BJH method reveal that the obtained carbon possesses a mesoporous characteristic,with the average pore size between 3.0 nm and 5.0 nm.The electrochemical properties of supercapacitor using these carbons as electrode material were investigated by cyclic voltammetry and constant current charge-discharge.The results indicate that the composition of blended polymers has a strong effect on the specific capacitance.When the mass ratio of PF to gelatin is kept at 1:1,the largest surface area of 222 m2/g is obtained,and the specific capacitance reaches 161 F/g.
