EG/CPDA复合材料的制备及其对苯气体的吸附

Preparation of EG/CPDA Composites and Their Adsorption of Benzene Gas

以多巴胺盐酸盐为碳源,采用原位浸渍活化工艺制备膨胀石墨/碳化聚多巴胺(EG/CPDA)复合材料,使用扫描电子显微镜、氮气吸脱附仪、傅里叶变换红外光谱仪等设备对EG/CPDA复合材料进行表征,考查CPDA微孔吸附结构的形成机理,研究醇水比、氨水浓度、KOH比例和碳化活化顺序对复合材料微观结构及对苯气体吸附性能的影响。结果表明:EG/CPDA复合材料,保留了碳化PDA的虚体孔道,架构出具有通透性微米级大孔和丰富的纳米级小孔的分级多孔碳材料;当醇水比为1∶2,氨水量0.4 g,800℃预碳化2 h,与KOH按1∶4混合,700℃活化1 h时,其比表面积和总孔容可达到1291 m^(2)/g和1.28 cm^(3)/g,对苯气体的吸附量可达1303 mg/g,并且表面富含的sp^(2) C/N有望提高苯气体对水蒸气的竞争性吸附能力。

Expanded graphite/carbonated polydopamine(EG/CPDA)composites were prepared by an in situ impregnation activation process using dopamine hydrochloride as the carbon source,and the EG/CPDA composites were characterized using scanning electron microscopy,nitrogen adsorption and desorption apparatus,Fourier transform infrared spectroscopy,etc.The formation mechanism of CPDA microporous adsorption structure was investigated,and the effects of alcohol-to-water ratio,ammonia concentration,The effects of alcohol-water ratio,ammonia concentration,KOH ratio and carbonization activation sequence on the microstructure and the adsorption performance of benzene gas were investigated.The results showed that the EG/CPDA composites retained the virtual pore channels of carbonized PDA,architected a graded porous carbon material with permeable micron-level macropores and abundant nanometer-level micropores;when the alcohol-to-water ratio was 1∶2,ammonia amount was 0.4 g,it was pre-carbonated at 800℃for 2 h,mixed with KOH at 1∶4 and activated at 700℃for 1 h,the specific surface area and total pore volume could reach 1291 m^(2)·g^(-1) and 1.28 cm^(3)·g^(-1),and the adsorption capacity of benzene gas could reach 1303 mg·g^(-1).Moreover,the sp2 C/N enriched surface was expected to improve the competitive adsorption of benzene gas to water vapor.