基于席夫碱反应合成氮掺杂的碳活化PMS降解双酚A  

Degradation of BPA by activating PMS over N-doped carbon synthesized based on Schiff base reaction

作　　者：吴尚迪 葛夏菁 余雅琳 夏芸 江芳[1] 陈欢[1] WU Shangdi;GE Xiajing;YU Yalin;XIA Yun;JIANG Fang;CHEN Huan(School of Environmental and Biological Engineering,Nanjing University of Science and Technology,Nanjing,210014,China)

机构地区：[1]南京理工大学环境与生物工程学院,南京210014

出　　处：《环境化学》2022年第1期340-351,共12页Environmental Chemistry

基　　金：中央高校基本科研业务费专项资金(30920021113)资助.

摘　　要：基于石墨相氮化碳(g-C_(3)N_(4))的热聚合形成过程和席夫碱反应,本文将尿素和2-萘甲醛作为前驱体,经一步热聚合反应制备了氮掺杂的碳材料(NCN-x),并以其作为催化剂活化过一硫酸盐(PMS)来降解双酚A(BPA).在催化剂特性研究部分,利用SEM、XRD、FTIR以及XPS对其表面形貌、结构与元素组成进行分析.结果表明,2-萘甲醛的加入使NCN-x催化剂的表面更加粗糙,提供更多活性位点;由XRD和FTIR的图谱可知,对应于g-C_(3)N_(4)中(100)晶面的峰强随着2-萘甲醛加入比例的增加而逐渐降低,表明NCN-x中的七嗪单元逐渐被破坏;由XPS表征结果可知,NCN-3中石墨N含量是g-C_(3)N_(4)中的20倍左右,使邻近碳原子带正电,并激活了碳原子上的π电子,提高对PMS的吸附性能.通过研究催化剂的加入量、PMS添加量、反应温度和初始pH值等对BPA降解的影响,发现催化剂和PMS的添加量均与降解效率呈正相关,催化剂的活化能为36.2 kJ·mol^(-1);初始pH值对反应体系的影响不大,说明催化剂有较强的抗pH波动干扰的能力.自由基猝灭实验表明,单线态氧是主要活性物种,且水中共存的氯离子对BPA降解的影响并不明显.Based on the thermal polymerization formation process of graphitic carbon nitride(g-C_(3)N_(4))and the Schiff base reaction,urea and 2-naphthaldehyde were used as precursors to prepare N-doped carbon catalysts(NCN-x).The obtained catalysts were used to activate peroxymonosulfate(PMS)to degradate bisphenol A(BPA).The characterization methods of SEM,XRD,FTIR and XPS were used to analyze the surface morphology,structure and elements composition of catalysts.The acquired results showed that the addition of 2-naphthaldehyde maked the surface of the NCN-x catalysts rougher,providing more activation sites.The analysis of the XRD and FTIR spectra showed that the(100)facet peak intensity of g-C_(3)N_(4) gradually decreased with the increase of the ratio of 2-naphthaldehyde during the preparation process of NCN-x,indicating that the heptazine unit was gradually destroyed.The results of XPS characterization indicated that the graphite N content of NCN-3 was about 20 times of that in g-C_(3)N_(4).The graphite N made the adjacent carbon atoms positively charged andπelectrons on the carbon atoms were activated to improve the adsorption performance of PMS.Further study concerning the effect of catalyst concentration,PMS concentration,reaction temperature and initial pH on the degradation of BPA indicated that the addition amount of the catalyst and PMS was positively related to the degradation efficiency of BPA.The Ea of NCN-3 was calculated to be 36.2 kJ·mol^(-1),and the initial pH had little effect on the reaction system,indicating that NCN-3 had a strong ability to resist the interference of pH fluctuations.Free radical quenching experiments indicated that the main active species was singlet oxygen,and the coexisting Cl^(-)in water had little effect on the degradation of BPA.

关 键 词：氮掺杂碳 过一硫酸盐 双酚A 单线态氧 

分 类 号：X703[环境科学与工程—环境工程]