K_(2)CO_(3)活化法油茶果壳活性炭的制备及表征

Preparation and Characterization Analysis of Activated Carbon from Camellia oleifera Shell by K_(2)CO_(3)

以油茶果壳(COS)为原料,K_(2)CO_(3)为活化剂,分别在空气和氮气中活化制备COS活性炭,探讨了活化温度、活化时间和K_(2)CO_(3)溶液浸渍COS的比例(浸渍比,mL∶g)对活性炭制备的影响,利用元素分析、傅里叶红外光谱(FT-IR)、扫描电镜(SEM)等手段对活性炭进行了表征。研究结果表明:在空气中活化,浸渍比值为1.5,温度为800℃,炭化活化时间为1 h的条件下,制得的活性炭得率为12.48%,BET比表面积为1080.94 m^(2)/g,亚甲基蓝(MB)吸附值为441.62 mg/g;在氮气中活化,浸渍比值为2.5,温度为800℃,炭化活化时间为1 h时,制得的活性炭得率为18.00%,BET比表面积为942.42 m^(2)/g,MB吸附值为428.77 mg/g。元素分析结果表明氮气气氛下制备的活性炭H/C元素比低,芳香性提高;FT-IR和SEM分析表明活化促进了活性炭—CH、—COOH热解和孔隙生长;相比N_(2)气氛下的样品,空气作热解气制备的活性炭孔隙更发达,吸附性能更好。

Using K_(2)CO_(3)as the activating agent,Camellia oleifera shell(COS)was used as the raw material to prepare COS-based activated carbon through activation in both air and nitrogen atmospheres.The effects of activation temperature,activation time,and K_(2)CO_(3)impregnation ratio(mL∶g)on the preparation of activated carbon were investigated.The activated carbon was characterized using elemental analysis,Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),and other methods.The results showed that with an impregnation ratio of 1.5,temperature of 800℃,and carbonization activation time of 1 h in air atmosphere,the obtained activated carbon had the yield of 12.48%,specific surface area o f 1080.94 m^(2)/g,and methylene blue(MB)adsorption value of 441.62 mg/g.When activated in nitrogen with impregnation ratio of 2.5,temperature of 800℃,and carbonization activation time of 1 h,the obtained activated carbon had the yield of 18.00%,specific surface area of 942.42 m^(2)/g,and MB adsorption value of 428.77 mg/g.The results of elemental analysis showed that activated carbon prepared under a nitrogen atmosphere had a lower H/C elemental ratio and the aromaticity was improved.FT-IR and SEM analysis indicated that activation promoted the thermal decomposition of—CH and—COOH groups and the growth of pores in the activated carbon.Compared to the samples prepared under a nitrogen atmosphere,activated carbon produced by air as pyrolysis had more developed pores and better adsorption performance.