芳胺废渣衍生多孔碳高效吸附去除对硝基苯酚

Efficient adsorption removal of p-nitrophenol by aromatic amine waste derived porous carbon

以工业生产过程中产生的芳胺废渣为碳前驱体,以四水合乙酸镁为氧化镁模板剂前驱体,采用一锅法制备了N、O原位共掺杂的分级多孔碳(RPCs)。通过SEM和N_(2)吸附-脱附、XPS对RPCs的形貌、孔结构及掺杂的N、O物种进行了测试,评价了RPCs对对硝基苯酚(PNP)的吸附容量,并理论计算了PNP分子在吸附剂表面的吸附行为。结果表明,由m(氧化镁)∶m(R废渣)=1.00∶1制备的RPC-1.00的比表面积为1427 m^(2)/g,孔容为1.4713 cm^(3)/g。在大的比表面积、丰富的孔结构和N、O掺杂物种的共同作用下,RPC-1.00对PNP的静态吸附容量达到了562.66 mg/g,固定床动态吸附容量达到了345.01 mg/g。N、O原子的掺入增加了吸附体系的色散力和静电吸引力,能有效提高吸附能。在缺陷处同时存在4个N原子的吡啶—N4和羧基结构也能产生很强的氢键强吸引力作用,提升了吸附能力。

N,O in-situ co-doped hierarchical porous carbons(RPCs)were prepared from one-pot reaction of industrial aromatic amine waste residue(R waste residue)and magnesium acetate tetrahydrate,and characterized via SEM,N_(2) adsorption-desorption and XPS for analyses on morphology,pore structure and doped N and O species.The adsorption capacity of RPCs to p-nitrophenol(PNP)was then evaluated,and the adsorption behavior of PNP molecules on the surface of the adsorbent was theoretically analyzed.The results showed that the specific surface area and pore volume of RPC-1.00 prepared by m(MgO)∶m(R waste residue)=1.00∶1 were 1427 m^(2)/g and 1.4713 cm^(3)/g,respectively.Under the synergistic action of large specific surface area,rich pore structure and N,O doped species,the static adsorption capacity of RPC-1.00 for PNP reached 562.66 mg/g,and the dynamic adsorption capacity of fixed bed reached 345.01 mg/g.The incorporation of N and O atoms increased the dispersion force and electrostatic attraction of the adsorption system,which could effectively improve the adsorption energy.The pyridine—N4 with 4 N atoms at the defect and carboxyl structure could also produce strong hydrogen bonding forces,which improved the adsorption capacity.