以核桃壳为碳源微波加热制备介孔活性炭

The preparation of mesoporous activated carbon by microwave radiation heating walnut shell

以核桃壳为碳源,微波辐射法制备了介孔活性炭。用XRD、SEM和低温氮气吸脱附对所制备活性炭进行了物性分析;用恒流充放电、循环伏安和交流阻抗等方法分析了微波功率、辐射时间对活性炭电容性能的影响。确定活性炭的最佳制备工艺为微波功率480W,辐射时间9min。制得的活性炭平均孔径为4.44nm,介孔率为78.51%,比表面积达1530m2/g,为不规则、疏松多孔的无定形结构。当充放电电流为100mA/g时,比电容为226.4F/g,循环1 000次后比电容为192.2F/g,每次循环电容衰减仅为0.015%。

The mesoporous activated carbon was prepared by microwave radiation process using walnut shell as carbon source.The as-prepared activated carbon was well characterized by XRD,SEM and nitrogen adsorption-desorption.The influences of microwave power and radiation time on the capacitance characteristics of activated carbon for electrochemical capacitors was investigated by glavanostatic charge-discharge,cyclic voltammetry (CV)and AC impedance spectroscopy.Microwave power at 480 W and radiation time for 9 min were regarded as the optimum process.The activated carbon prepared under this process had the average pore size of 4.44 nm and the mesoporous rate of 78.51 %.The specific surface area was 1 530 m2/g and its shape was irregular,porous and amorphous structure.The specific capacitance was 226.4 F/g at the charge-discharge current of 100 mA/g. It kept 192.2 F/g after 1 000 cycles,and the capacity fade of activated carbon was only 0.015 % when cycled at 100 mA/g.