K^(+)诱导氰基修饰g-C_(3)N_(4)光催化剂的一步合成及性能  

One-step synthesis and properties of K^(+)-induced cyano-modified g-C_3N_(4) for photocatalystenhanced photocatalyst

作　　者：李亚莹 薛小刚[1,2,3] 徐芬 孙立贤[1,2,3] 王颖晶[1,2,3] 廖鹿敏 李彬 邹勇进 张焕芝[1,2,3] LI Yaying;XUE Xiaogang;XU Fen;SUN Lixian;WANG Yingjing;LIAO Lumin;LI Bin;ZOU Yongjin;ZHANG Huanzhi(School of Materials Science and Engineering,Guilin University of Electronic Technology,Guilin 541004,China;Guangxi Collaborative Innovation Centre of Structure and Property for New Energy and Materials,Guilin University of Electronic Technology,Guilin 541004,China;Guangxi Key Laboratory of Information Materials,Guilin University of Electronic Technology,Guilin 541004,China)

机构地区：[1]桂林电子科技大学材料科学与工程学院,广西桂林541004 [2]桂林电子科技大学广西新能源新材料结构与性能协同创新中心,广西桂林541004 [3]桂林电子科技大学广西信息材料重点实验室,广西桂林541004

出　　处：《桂林电子科技大学学报》2023年第4期295-305,共11页Journal of Guilin University of Electronic Technology

基　　金：国家重点研发项目(2018YFB1501203,2018YFB1501205);国家自然科学基金(51971068,5187011196);广西新能源材料结构与性能协同创新中心课题(2012GXNSFGA06002);广西科技计划(AD17195073);广西科技重大专项(AA17202030-1)。

摘　　要：为了提高石墨相氟化碳(g-C_(3)N_(4))的可见光利用率,采用同时加热尿素和氢氧化钾的一步热缩合法制备K^(+)掺杂g-C_(3)N_(4)(CN-K_(x))。XRD、SEM、TEM和EDX图谱分析表明,K^(+)成功地掺杂在g-C_(3)N_(4)上;FTIR和XPS结果证实K^(+)掺杂后g-C_(3)N_(4)表面有氰基生成;PL、EIS和瞬态光电流响应数据表明,掺杂后形成的氰基与K^(+)之间具有协同作用,这有利于光生电子-空穴的分离和转移,提高光催化活性。光降解实验结果表明,优化后的CN-K_(0.009)样品在80 min内能去除100%的罗丹明B (RhB),且RhB的降解速率达0.054 min^(-1),是纯氮化碳的4.2倍(降解速率为0.013 min^(-1));进一步的带隙分析表明,CN-K_(0.009)的带隙从纯氮化碳的2.67 eV缩短到2.59 eV,这是由于K^(+)辅助聚合的作用增强了可见光吸收和载流子传输。动力学研究结果表明,超氧自由基和空穴(h^(+))主导了RhB氧化过程。另外,CN-K_(0.009)同样能高效降解其他有机污染物,比如碱性品红(91.7%)、刚果红(85.7%)和四环素(74%)。To improve the visible light utilization of graphitic carbon nitride(g-C_(3)N_(4)),K^(+) doped g-C_(3)N_(4)(CN-K_x) are fabricated via one-step thermal condensation through the simultaneous heating of urea and potassium hydroxide.XRD,SEM,TEM and EDX mapping analysis demonstrate that K^(+) is successfully doped onto g-C_(3)N_(4);the FTIR and XPS analysis results confirm the formation of cyano groups on the surface of the g-C_(3)N_(4);PL spectra,EIS and the transient photocurrent response indicate the synergistic effect of the cyano groups and K^(+),which favors the separation and transfer of photogenerated electron-holes for boosting photocatalytic activity.The experiments prove that the rhodamine B(RhB) removal rate of optimized CN-K_(0.009) sample is 100% within 80 min;its degradation rate(k) is 0.054 min^(-1),4.2 times that of pristine CN(k=0.013 min^(-1)),and its RhB removal rate is 100% within 80 min;further band analysis suggests that the bandgap of CN-K_(0.009) reduces from 2.67 eV(for CN) to 2.59 eV owing to K^(+) assisted polymerization enhanced visible light harvesting and carriers′ transportation.Kinetic investigations reveal that superoxide radicals and holes(h^(+)) dominate the oxidation process of RhB.Moreover,the CN-K_(0.009) can be expanded to efficient degradation of many organic pollutants,such as basic fuchsin(91.7%),Congo red(85.7%) and tetracycline(74%).

关 键 词：石墨相氮化碳 氰基 钾离子 光催化RhB降解 电荷转移 

分 类 号：O643.361[理学—物理化学]