Mg/O共同修饰无定形氮化碳的独特电子结构增强光催化对四环素盐酸盐的降解（英文）
|
摘要
近年来,光催化技术被广泛应用于环境和能源领域.其中,g-C_3N_4因化学稳定性和热稳定性好、能带结构易调控而成为一种有前景的可见光光催化剂.然而,g-C_3N_4的电子-空穴对易复合,导致其不能充分利用太阳光,光催化效率并不理想.本文通过实验与理论结合的方法设计并制备了具有独特电子结构的Mg/O共同修饰的无定形氮化碳(记为MgO-CN),以30mg/L的四环素盐酸溶液(TC)作为目标污染物评价了其光催化性能.经X射线衍射、扫描电镜、透射电镜、N_2物理吸附、紫外-可见光谱等表征手段分析表明,MgO-CN样品(002)晶面的衍射峰强度随着MgO含量增加而减弱,CN趋向于无定形化.同时,MgO-CN样品的可见光吸收边带发生红移,呈现出更强的可见光吸收能力.此外,Mg原子和O原子共同修饰的独特电子结构可以通过C→O←Mg的电子传递路线在O原子周围产生局域电子,从而抑制电子-空穴的复合.光催化降解TC的实验结果表明,在可见光照射后,含有1.2 wt%MgO的复合样品MgO-CN-1.2具有最佳光催化活性,TC降解效率为82.0%,比g-C_3N_4的光催化效率(23.5%)高出58.5%,且光催化降解过程符合准一级动力学,MgO-CN-1.2的反应速率常数(0.01018 min~(–1))是g-C_3N_4(0.00205 min~(–1))的5倍.自由基捕获测试实验表明,g-C_3N_4和Mg O-CN-1.2样品均可以产生·O_2~–自由基和·OH自由基,但是Mg O-CN-1.2样品的·O_2~–和·OH信号更强.这是由于Mg O-CN-1.2样品可以吸收更大范围的可见光用于激发电子,同时结合理论计算证明,MgO-CN内部电子在O原子周围汇集,形成的电子定向传输通道对催化剂表面的电子-空穴复合有抑制作用,更加有利于电子的迁移而诱导O_2生成·O_2~–.由于Mg O-CN-1.2和g-C_3N_4的价带位置分别位于1.47和1.60 eV,此价带上的h~+不能与H_2O和OH~–直接反应生成·OH,而是由生成的·O_2~–再与H~+和e~–按照O_2→·O_2→H_2O_2→·OH的反应途径生成·OH.本文最后分析,MgO-CN复合物参与反应的主要活性物种为·O_2~–,·OH和h~+光催化降解污染物的反应机理.其中,·O_2~–对光催化降解TC的贡献最大,为最主要的活性物质.本文工作提供了一种新的策略来改变氮化碳的电子结构,对提高其催化性能具有积极意义.
g-C_3N_4 is a hot visible light photocatalyst.However,the fast recombination of photogenerated electron-hole pairs leads to unsatisfactory photocatalytic efficiencies.In this study,Mg/O co-decorated amorphous carbon nitride(labeled as MgO-CN)with a unique electronic structure was designed and prepared via a combined experimental and theoretical approach.The results showed that the Mg O-CN exhibited an increased light absorption ability and promoted charge separation efficiency.The Mg and O co-decoration created a unique structure that could generate localized electrons around O atoms and enhance the reactant activation capacities via the C→O←Mg route.This could dramatically promote the O_2 molecule activation on the catalyst surface to generate reactive species(·O_2~–/·OH).The optimized MgO-CN exhibited a high photocatalytic activity for the degradation of tetracycline hydrochloride in water,which was five times higher than that of pristine g-C_3N_4.The present work could provide a new strategy for modifying the electronic structure of g-C_3N_4 and enhancing its performance for environmental applications.
g-C_3N_4 is a hot visible light photocatalyst.However,the fast recombination of photogenerated electron-hole pairs leads to unsatisfactory photocatalytic efficiencies.In this study,Mg/O co-decorated amorphous carbon nitride(labeled as MgO-CN)with a unique electronic structure was designed and prepared via a combined experimental and theoretical approach.The results showed that the Mg O-CN exhibited an increased light absorption ability and promoted charge separation efficiency.The Mg and O co-decoration created a unique structure that could generate localized electrons around O atoms and enhance the reactant activation capacities via the C→O←Mg route.This could dramatically promote the O_2 molecule activation on the catalyst surface to generate reactive species(·O_2~–/·OH).The optimized MgO-CN exhibited a high photocatalytic activity for the degradation of tetracycline hydrochloride in water,which was five times higher than that of pristine g-C_3N_4.The present work could provide a new strategy for modifying the electronic structure of g-C_3N_4 and enhancing its performance for environmental applications.
引文
[1]I.Chopra,M.Roberts,Microbiol.Mol.Biol.Rew.,2001,65,232-260.
[2]S.Leong,D.Li,K.Hapgood,X.Zhang,H.Wang,Appl.Catal.B,2016,198,224-233.
[3]H.Chen,S.Liu,X.R.Xu,Z.H.Diao,K.F.Sun,Q.W.Hao,S.S.Liu,G.G.Ying,J.Hazard.Mater.,2018,343,140-148.
[4]Q.Z.Yi,Y.Zhang,Y.X.Gao,Z.Tian,M.Yang,Water Res.,2017,110,211-217.
[5]J.Li,W.Zhang,M.Ran,Y.Sun,H.Huang,F.Dong,Appl.Catal.B,2019,243,313-321.
[6]S.H.Kim,H.K.Shon,H.H.Ngo,J.Ind.Eng.Chem.,2010,16,344-349.
[7]I.de Godos,R.Mu?oz,B.Guieysse,J.Hazard.Mater.,2012,229-230,446-449.
[8]H.Kim,Y.Hong,J.E.Park,V.K.Sharma,S.I.Cho,Chemosphere,2013,91,888-894.
[9]J.Y.Li,X.A.Dong,Y.J.Sun,W.L.Cen,F.Dong,Appl.Catal.B,2018,226,269-277.
[10]X.J.Wen,C.G.Niu,L.Zhang,C.Liang,G.M.Zeng,Appl.Catal.B,2018,221,701-714.
[11]C.Xie,S.H.Yang,J.W.Shi,B.B.Li,C.Gao,C.M.Niu,J.Colloid Interf.Sci.,2016,476,1-8.
[12]Y.H.Li,K.L.Lv,W.K.Ho,F.Dong,X.F.Wu,Y.Xia,Appl.Catal.B,2017,202,611-619.
[13]J.Y.Hu,C.K.Yu,C.Y.Zhu,S.J.Hu,Y.Wang,N.Q.Fu,L.X.Zeng,M.S.Zhu,Catal.Today,2018,315,36-45.
[14]G.Zhang,W.Guan,H.Shen,X.Zhang,W.Fan,C.Lu,H.Bai,L.Xiao,W.Gu,W.Shi,Ind.Eng.Chem.Res.,2014,53,5443-5450
[15]T.Wang,W.Quan,D.Jiang,L.Chen,D.Li,Chem.Eng.J.,2016,300,280-290.
[16]A.Dehghan,M.H.Dehghani,R.Nabizadeh,N.Ramezanian,M.Alimohammadi,A.A.Najafpoor,Chem.Eng.Res.Des.,2018,129,217-230.
[17]Q.Zhang,I.Lee,J.B.Joo,F.Zaera,Y.Yin,Acc.Chem.Res.,2013,46,1816-1824.
[18]J.Y.Li,Z.Y.Zhang,W.Cui,H.Wang,W.L.Cen,G.Johnson,G.M.Jiang,S.Zhang,F.Dong,ACS Catal.,2018,8,8376-8385.
[19]X.C.Wang,K.Maeda,A.Thomas,K.Takanabe,G.Xin,J.M Carlsson,K.Domen,M.Antonietti,Nat.Mater.,2009,8,76-80.
[20]W.H.Niu,K.Marcus,L.Zhou,Z.Li,L.Shi,K.Liang,Y.Yang,ACSCatal.,2018,8,1926-1931.
[21]F.Geng,R.Ma,A.Nakamura,K.Akatsuka,Y.Ebina,Y.Yamauchi,N.Miyamoto,Y.Tateyama,T.Sasaki,Nat.Commun.,2013,4,1632/1-1632/7.
[22]J.Y.Li,W.Cui,Y.J.Sun,Y.H.Chu,W.L.Cen,F.Dong,J.Mater.Chem.A,2017,5,9358-9364.
[23]P.Suyana,P.Ganguly,B.N.Nair,A.P.Mohamed,K.G.K.Warrier,U.S.Hareesh,Environ.Sci.:Nano,2017,4,212-221.
[24]Y.Kang,Y.Yang,L.C.Yin,X.Kang,L.Wang,G.Liu,H.M.Cheng,Adv.Mater.,2016,28,6471-6477.
[25]P.Chen,H.Wang,H.Liu,Z.Ni,J.Li,Y.Zhou,F.Dong,Appl.Catal.B,2019,242,19-30.
[26]X.Dong,W.Zhang,Y.Sun,J.Li,W.Cen,Z.Cui,H.Huang,F.Dong,J.Catal.,2018,357,41-50.
[27]W.Cui,J.Y.Li,F.Dong,Y.J.Sun,G.M.Jiang,W.L.Cen,S.C.Lee,Z.B.Wu,Environ.Sci.Technol.,2017,51,10682-10690.
[28]J.Jiang,S.W.Cao,C.L.Hu,C.H.Chen,Chin.J.Catal.,2017,38,1981-1989.
[29]F.Chen,H.Yang,X.F.Wang,H.G.Yu,Chin.J.Catal.,2017,38,296-304.
[30]H.J.Han,M.Fu,Y.L.Li,W.Guan,P.Lu,X.L.Hu,Chin.J.Catal.,2018,39,831-840.
[31]Y.H.Li,K.L.Lv,W.K.Ho,Z.W.Zhao,Y.Huang,Chin.J.Catal.,2017,38,321-329.
[32]H.W.Jung,T.T.Pham,E.W.Shin,Appl Sur Sci.,2018,458,369-381
[33]Q.Q.Hao,Y.H.Song,H.Y.Ji,Z.Mo,X.J.She,J.J.Deng,T.Muhmood,X.W.Wu,S.Q.Yuan,H.Xu,H.M.Li,Appl.Surf.Sci.,2018,459,845-852.
[34]T.Xiong,W.Cen,Y.Zhang,F.Dong,ACS Catal.,2016,6,2462-2472.
[35]M.S.Zhu,S.Kim,L.Mao,M.Fujitsuka,J.Y.Zhang,X.C.Wang,T.Majima,J.Am.Chem.Soc.,2017,139,13234-13242.
[36]M.S.Zhu,C.Y.Zhai,M.J.Sun,Y.F.Hu,B.Yan,Y.K.Du,Appl.Catal.B,2017,203,108-115.
[37]C.Y.Zhai,M.J.Sun,L.X.Zeng,M.Q.Xue,J.G.Pan,Y.K.Du,M.S.Zhu,Appl.Catal.B,2019,243,283-293.
[38]Y.Z.Hong,C.S.Li,B.X.Yin,D.Li,Z.Y.Zhang,B.D.Mao,W.Q.Fan,W.Gu,W.D.Shi,Chem.Eng.J.,2018,338,137-146.
[39]G.Kresse,J.Furthmüller,Phys.Rev.B,1996,54,11169-11186.
[40]N.Huo,H.Ma,X.H.Wang,T.L.Wang,G.Wang,T.Wang,L.L.Hou,J.Gao,J.Xu,Chin.J.Catal.,2017,38,1148-1154.
[41]X.Wang,S.Blechert,M.Antonietti,ACS Catal.,2012,2,1596-1606.
[42]J.S.Chen,Z.Hu,K.L.Lv,X.F.Wu,Q.Li,Y.H.Li,X.F.Li,J.Sun,Appl.Catal.B,2018,232,330-339.
[43]Y.Zheng,L.H.Lin,B.Wang,X.C.Wang,Angew.Chem.Int.Ed.,2015,54,12868-12884.
[44]Y.Li,Y.Sun,W.Ho,Y.Zhang,H.Huang,Q.Cai,F.Dong,Sci.Bull.,2018,63,609-620.
[45]Z.Zhao,H.Dai,Y.Du,J.Deng,L.Zhang,F.Shi,Mater.Chem.Phys.,2011,128,348-356.
[46]H.Niu,Q.Yang,K.Tang,Y.Xie,J.Nanopart.Res.,2006,8,881-888.
[47]J.Fu,B.Zhu,C.Jiang,B.Cheng,W.You,J.G.Yu,Small,2017,13,1603938/1-1603938/9.
[48]M.J.Bojdys,J.O.Muller,M.Antonietti,A.Thomas,Chem.Eur.J.,2008,14,8177-8182.
[49]C.L.Schmidt,M.Jansen,J.Mater.Chem.,2010,20,4183-4192.
[50]S.Z.Hu,L.Ma,H.Y.Wang,L.Zhang,Y.F.Zhao,G.Wu,RSC Adv.,2015,5,31947-31953.
[51]J.Y.Li,X.A.Dong,Y.J.Sun,G.M.Jiang,Y.H.Chu,S.C.Lee,F.Dong,Appl.Catal.B,2018,239,187-195.
[52]J.Y.Li,P.Yan,K.L.Li,W.L.Cen,X.W.Yu,S.D.Yuan,Y.H.Chu,Z.M.Wang,Chin.J.Catal.,2018,39,1695-1703.
[53]Y.H.Li,W.K.Ho,K.L.Lv,B.C.Zhu,S.C.Lee,Appl.Surf.Sci.,2018,430,380-389.
[54]W.Cui,J.Li,Y.Sun,H.Wang,G.Jiang,S.C.Lee,F.Dong,Appl.Catal.B,2018,237,938-946.
[55]X.Dong,J.Li,Q.Xing,Y.Zhou,H.Huang,F.Dong,Appl.Catal.B,2018,232,69-76.
[2]S.Leong,D.Li,K.Hapgood,X.Zhang,H.Wang,Appl.Catal.B,2016,198,224-233.
[3]H.Chen,S.Liu,X.R.Xu,Z.H.Diao,K.F.Sun,Q.W.Hao,S.S.Liu,G.G.Ying,J.Hazard.Mater.,2018,343,140-148.
[4]Q.Z.Yi,Y.Zhang,Y.X.Gao,Z.Tian,M.Yang,Water Res.,2017,110,211-217.
[5]J.Li,W.Zhang,M.Ran,Y.Sun,H.Huang,F.Dong,Appl.Catal.B,2019,243,313-321.
[6]S.H.Kim,H.K.Shon,H.H.Ngo,J.Ind.Eng.Chem.,2010,16,344-349.
[7]I.de Godos,R.Mu?oz,B.Guieysse,J.Hazard.Mater.,2012,229-230,446-449.
[8]H.Kim,Y.Hong,J.E.Park,V.K.Sharma,S.I.Cho,Chemosphere,2013,91,888-894.
[9]J.Y.Li,X.A.Dong,Y.J.Sun,W.L.Cen,F.Dong,Appl.Catal.B,2018,226,269-277.
[10]X.J.Wen,C.G.Niu,L.Zhang,C.Liang,G.M.Zeng,Appl.Catal.B,2018,221,701-714.
[11]C.Xie,S.H.Yang,J.W.Shi,B.B.Li,C.Gao,C.M.Niu,J.Colloid Interf.Sci.,2016,476,1-8.
[12]Y.H.Li,K.L.Lv,W.K.Ho,F.Dong,X.F.Wu,Y.Xia,Appl.Catal.B,2017,202,611-619.
[13]J.Y.Hu,C.K.Yu,C.Y.Zhu,S.J.Hu,Y.Wang,N.Q.Fu,L.X.Zeng,M.S.Zhu,Catal.Today,2018,315,36-45.
[14]G.Zhang,W.Guan,H.Shen,X.Zhang,W.Fan,C.Lu,H.Bai,L.Xiao,W.Gu,W.Shi,Ind.Eng.Chem.Res.,2014,53,5443-5450
[15]T.Wang,W.Quan,D.Jiang,L.Chen,D.Li,Chem.Eng.J.,2016,300,280-290.
[16]A.Dehghan,M.H.Dehghani,R.Nabizadeh,N.Ramezanian,M.Alimohammadi,A.A.Najafpoor,Chem.Eng.Res.Des.,2018,129,217-230.
[17]Q.Zhang,I.Lee,J.B.Joo,F.Zaera,Y.Yin,Acc.Chem.Res.,2013,46,1816-1824.
[18]J.Y.Li,Z.Y.Zhang,W.Cui,H.Wang,W.L.Cen,G.Johnson,G.M.Jiang,S.Zhang,F.Dong,ACS Catal.,2018,8,8376-8385.
[19]X.C.Wang,K.Maeda,A.Thomas,K.Takanabe,G.Xin,J.M Carlsson,K.Domen,M.Antonietti,Nat.Mater.,2009,8,76-80.
[20]W.H.Niu,K.Marcus,L.Zhou,Z.Li,L.Shi,K.Liang,Y.Yang,ACSCatal.,2018,8,1926-1931.
[21]F.Geng,R.Ma,A.Nakamura,K.Akatsuka,Y.Ebina,Y.Yamauchi,N.Miyamoto,Y.Tateyama,T.Sasaki,Nat.Commun.,2013,4,1632/1-1632/7.
[22]J.Y.Li,W.Cui,Y.J.Sun,Y.H.Chu,W.L.Cen,F.Dong,J.Mater.Chem.A,2017,5,9358-9364.
[23]P.Suyana,P.Ganguly,B.N.Nair,A.P.Mohamed,K.G.K.Warrier,U.S.Hareesh,Environ.Sci.:Nano,2017,4,212-221.
[24]Y.Kang,Y.Yang,L.C.Yin,X.Kang,L.Wang,G.Liu,H.M.Cheng,Adv.Mater.,2016,28,6471-6477.
[25]P.Chen,H.Wang,H.Liu,Z.Ni,J.Li,Y.Zhou,F.Dong,Appl.Catal.B,2019,242,19-30.
[26]X.Dong,W.Zhang,Y.Sun,J.Li,W.Cen,Z.Cui,H.Huang,F.Dong,J.Catal.,2018,357,41-50.
[27]W.Cui,J.Y.Li,F.Dong,Y.J.Sun,G.M.Jiang,W.L.Cen,S.C.Lee,Z.B.Wu,Environ.Sci.Technol.,2017,51,10682-10690.
[28]J.Jiang,S.W.Cao,C.L.Hu,C.H.Chen,Chin.J.Catal.,2017,38,1981-1989.
[29]F.Chen,H.Yang,X.F.Wang,H.G.Yu,Chin.J.Catal.,2017,38,296-304.
[30]H.J.Han,M.Fu,Y.L.Li,W.Guan,P.Lu,X.L.Hu,Chin.J.Catal.,2018,39,831-840.
[31]Y.H.Li,K.L.Lv,W.K.Ho,Z.W.Zhao,Y.Huang,Chin.J.Catal.,2017,38,321-329.
[32]H.W.Jung,T.T.Pham,E.W.Shin,Appl Sur Sci.,2018,458,369-381
[33]Q.Q.Hao,Y.H.Song,H.Y.Ji,Z.Mo,X.J.She,J.J.Deng,T.Muhmood,X.W.Wu,S.Q.Yuan,H.Xu,H.M.Li,Appl.Surf.Sci.,2018,459,845-852.
[34]T.Xiong,W.Cen,Y.Zhang,F.Dong,ACS Catal.,2016,6,2462-2472.
[35]M.S.Zhu,S.Kim,L.Mao,M.Fujitsuka,J.Y.Zhang,X.C.Wang,T.Majima,J.Am.Chem.Soc.,2017,139,13234-13242.
[36]M.S.Zhu,C.Y.Zhai,M.J.Sun,Y.F.Hu,B.Yan,Y.K.Du,Appl.Catal.B,2017,203,108-115.
[37]C.Y.Zhai,M.J.Sun,L.X.Zeng,M.Q.Xue,J.G.Pan,Y.K.Du,M.S.Zhu,Appl.Catal.B,2019,243,283-293.
[38]Y.Z.Hong,C.S.Li,B.X.Yin,D.Li,Z.Y.Zhang,B.D.Mao,W.Q.Fan,W.Gu,W.D.Shi,Chem.Eng.J.,2018,338,137-146.
[39]G.Kresse,J.Furthmüller,Phys.Rev.B,1996,54,11169-11186.
[40]N.Huo,H.Ma,X.H.Wang,T.L.Wang,G.Wang,T.Wang,L.L.Hou,J.Gao,J.Xu,Chin.J.Catal.,2017,38,1148-1154.
[41]X.Wang,S.Blechert,M.Antonietti,ACS Catal.,2012,2,1596-1606.
[42]J.S.Chen,Z.Hu,K.L.Lv,X.F.Wu,Q.Li,Y.H.Li,X.F.Li,J.Sun,Appl.Catal.B,2018,232,330-339.
[43]Y.Zheng,L.H.Lin,B.Wang,X.C.Wang,Angew.Chem.Int.Ed.,2015,54,12868-12884.
[44]Y.Li,Y.Sun,W.Ho,Y.Zhang,H.Huang,Q.Cai,F.Dong,Sci.Bull.,2018,63,609-620.
[45]Z.Zhao,H.Dai,Y.Du,J.Deng,L.Zhang,F.Shi,Mater.Chem.Phys.,2011,128,348-356.
[46]H.Niu,Q.Yang,K.Tang,Y.Xie,J.Nanopart.Res.,2006,8,881-888.
[47]J.Fu,B.Zhu,C.Jiang,B.Cheng,W.You,J.G.Yu,Small,2017,13,1603938/1-1603938/9.
[48]M.J.Bojdys,J.O.Muller,M.Antonietti,A.Thomas,Chem.Eur.J.,2008,14,8177-8182.
[49]C.L.Schmidt,M.Jansen,J.Mater.Chem.,2010,20,4183-4192.
[50]S.Z.Hu,L.Ma,H.Y.Wang,L.Zhang,Y.F.Zhao,G.Wu,RSC Adv.,2015,5,31947-31953.
[51]J.Y.Li,X.A.Dong,Y.J.Sun,G.M.Jiang,Y.H.Chu,S.C.Lee,F.Dong,Appl.Catal.B,2018,239,187-195.
[52]J.Y.Li,P.Yan,K.L.Li,W.L.Cen,X.W.Yu,S.D.Yuan,Y.H.Chu,Z.M.Wang,Chin.J.Catal.,2018,39,1695-1703.
[53]Y.H.Li,W.K.Ho,K.L.Lv,B.C.Zhu,S.C.Lee,Appl.Surf.Sci.,2018,430,380-389.
[54]W.Cui,J.Li,Y.Sun,H.Wang,G.Jiang,S.C.Lee,F.Dong,Appl.Catal.B,2018,237,938-946.
[55]X.Dong,J.Li,Q.Xing,Y.Zhou,H.Huang,F.Dong,Appl.Catal.B,2018,232,69-76.