摘要
采用溶剂热合成法制备ZIF-8,在500~800℃的惰性气氛下煅烧得到N掺杂多孔碳,研究了高温碳化对ZIF-8结构演化的影响规律以及对亚甲基蓝光催化降解反应的强化机理.结果表明,碳化后ZIF-8颗粒发生坍塌和团聚,形成石墨相结构的Zn-C复合物,碳层作为受体能够快速转移光生电子,抑制电子-空穴对复合;同时表面产生具有氧化性的H-N-C=O和C-O官能团,能够促进光催化反应中自由基的生成.C700/ZIF-8具有最高的暂态光电流密度和最小的电荷传质阻抗,光谱吸收范围拓展至200~900nm的紫外-可将光波段,且在光催化过程中产生大量的超氧自由基和羟基自由基,对亚甲基蓝的光催化降解效率达到97%.
ZIF-8 was prepared by solvothermal synthesis,and N-doped porous carbon was obtained by calcining in an inert atmosphere at 500~800℃.The influence of high temperature carbonization on the structure evolution of ZIF-8 and the enhancement mechanism of photocatalytic degradation of methylene blue were systematically studied.The ZIF-8 particles collapsed and agglomerated after carbonization,forming Zn-C complex with graphite phase structure.The carbon layer,as a receptor,could rapidly transfer photogenerated electrons and inhibit electron hole pair recombination.At the same time,oxidized H-N-C=O and C-O functional groups were generated on the surface,which could promote the formation of free radicals in the photocatalytic reaction.C700/ZIF-8 had the highest transient photoelectric current density and the smallest electrochemical impedance,the spectral absorption range was extended to 200~900nm range.In addition,a great number of superoxide free radicals and hydroxyl free radicals were generated during the photocatalytic process,resulting in the highest methylene blue photocatalytic degradation efficiency of 97%.
作者
于馨凝
姜欣彤
许德军
张军
倪章松
王茂
王辛龙
YU Xin-ning;JIANG Xin-tong;XU De-jun;ZHANG Jun;NI Zhang-song;WANG Mao;WANG Xin-long(Chengdu Fluid Dynamics Innovation Center,Chengdu 610071,China;School of Chemical Engineering,Sichuan University,Chengdu 610044,China)
出处
《中国环境科学》
CSCD
北大核心
2023年第S1期110-117,共8页
China Environmental Science
