摘要
利用二氨基马来腈(DMNA)与二聚氰胺(DCDA)的高温共聚合反应,制备了石墨相氮化碳(g-C3N4),并通过X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱、透射电镜(TEM)、氮气吸脱附实验(N2-sorption)、电子顺磁共振(EPR)、紫外-可见漫反射光谱(UV-VisDRS)和荧光(PL)光谱等表征手段,系统考察了共聚合改性对g-C3N4晶体结构、化学结构、能带结构、织构、光吸收性能和光催化性能等的影响.研究结果表明:共聚合改性后氮化碳材料仍保持石墨相晶体结构,但其π电子的离域性增强,并在催化剂表面产生异质结构,进而提高了氮化碳在可见光区域的光吸收性能,并促进了光生载流子的有效分离.性能评价结果显示,DMNA改性的氮化碳在可见光下光催化产氢活性明显高于未改性的样品,当DMNA用量为0.01g时,催化剂的产氢速率最高,达到45.0μmol·h-1,为纯氮化碳样品的4.5倍.
g-C3N4 photocatalysts were synthesized by copolymerization of diaminomaleonitrile (DMNA) with dicyanodiamide (DCDA) at high temperatures.The effect of copolymerization on the crystal structure,chemical structure,band structure,texture,optical property,and photocatalytic performance of g-C3N4 was studied by such characterization techniques as X-ray diffraction (XRD) patterns,Fourier transformed infrared (FTIR),transmission electron microscopy (TEM),nitrogen-sorption (N2-sorption),electron paramagnetic resonance (EPR),ultraviolet-visble diffuse reflectance spectra (UV-Vis DSR),and photoluminescence (PL) analyses.Results demonstrated that the graphitic-like layer packing structure of g-C3N4 remained unchanged after the modification;however the copolymerization with DMNA can efficiently extend the delocalization of π-electrons and induce the formation of surface junctions,greatly enhancing the light-harvesting ability of g-C3N4 in visible light region and promoting the separation of photogenerated charge carriers,respectively.Photocatalytic performance showed that all DMNA-modified samples presented an enhanced H2 evolution activity under visible light irradiation.The optimized weight-in amount of DMNA is found to be 0.01g,by which the modified sample shows the highest hydrogen evolution rate of 45.0μmol·h-1.This value is 4.5 times as high as that of the unmodified carbon nitride sample.
引文
(1)Liu,A.Y.;Cohen,M.L.Science1989,245,841.doi:10.1126/science.245.4920.841
(2)Teter,D.M.;Hemley,R.J.Science1996,271,53.doi:10.1126/science.271.5245.53
(3)Kroke,E.;Schwarz,M.;Horath-Bordon,E.;Kroll,P.;Noll,B.;Norman,A.D.N.J.Chem.2002,26,508.doi:10.1039/b111062b
(4)Thomas,A.;Fischer,A.;Goettmann,F.;Antonietti,M.;Müller,J.O.;Schlgl,R.;Carlsson,J.M.J.Mater.Chem.2008,18,4893.doi:10.1039/b800274f
(5)Donnet,C.;Erdemir,A.Surf.Coat.Technol.2004,76,180.
(6)Goettmann,F.;Fischer,A.;Antonietti,M.;Thomas,A.Angew.Chem.Int.Edit.2006,45,4467.doi:10.1002/(ISSN)1521-3773
(7)Zhao,H.;Lei,M.;Yang,X.;Jian,J.;Chen,X.J.Am.Chem.Soc.2005,127,15722.doi:10.1021/ja055877i
(8)Wang,X.;Maeda,K.;Thomas,A.;Takanabe,K.;Xin,G.;Carlsson,J.M.;Domen,K.;Antonietti,M.Nat.Mater.2009,8,76.doi:10.1038/nmat2317
(9)Maeda,K.;Wang,X.;Nishihara,Y.;Lu,D.;Antonietti,M.;Domen,K.J.Phys.Chem.C2009,113,4940.doi:10.1021/jp809119m
(10)Zhang,J.;Sun,J.;Maeda,K.;Domen,K.;Liu,P.;Antonietti,M.;Fu,X.;Wang,X.Energy Environ.Sci.2010,4,675.
(11)Wang,X.;Maeda,K.;Chen,X.;Takanabe,K.;Domen,K.;Hou,Y.;Fu,X.;Antonietti,M.J.Am.Chem.Soc.2009,131,1680.doi:10.1021/ja809307s
(12)Chen,X.;Jun,Y.S.;Takanabe,K.;Maeda,K.;Domen,K.;Fu,X.;Antonietti,M.;Wang,X.Chem.Mater.2009,21,4093.doi:10.1021/cm902130z
(13)Di,Y.;Wang,X.;Thomas,A.;Antonietti,M.ChemCatChem2010,2,834.doi:10.1002/cctc.201000057
(14)Zhang,J.;Grzelczak,M.;Hou,Y.;Maeda,K.;Domen,K.;Fu,X.;Antonietti,M.;Wang,X.Chem.Sci.2011,3,443.
(15)Wang,X.;Chen,X.;Thomas,A.;Fu,X.;Antonietti,M.Adv.Mater.2009,21,1609.doi:10.1002/adma.v21:16
(16)Chen,X.;Zhang,J.;Fu,X.;Antonietti,M.;Wang,X.J.Am.Chem.Soc.2009,131,11658.doi:10.1021/ja903923s
(17)Liu,G.;Niu,P.;Sun,C.;Smith,S.C.;Chen,Z.;Lu,G.Q.;Cheng,H.M.J.Am.Chem.Soc.2010,132,11642.doi:10.1021/ja103798k
(18)Cui,Y.;Zhang,J.;Zhang,G.;Huang,J.;Liu,P.;Antonietti,M.;Wang,X.J.Mater.Chem.2011,21,13032.doi:10.1039/c1jm11961c
(19)Zhang,G.;Zhang,J.;Zhang,M.;Wang,X.J.Mater.Chem.2012,22,8083.doi:10.1039/c2jm00097k
(20)Zhang,J.;Zhang,M.;Zhang,G.;Wang,X.ACS Catal.2012,2,940.doi:10.1021/cs300167b
(21)Zhang,J.;Chen,X.;Takanabe,K.;Maeda,K.;Domen,K.;Epping,J.D.;Fu,X.;Antonietti,M.;Wang,X.Angew.Chem.Int.Edit.2010,49,441.doi:10.1002/anie.200903886
(22)Zhang,J.;Zhang,G.;Chen,X.;Lin,S.;Mhlmann,L.;Doga,G.;Lipner,G.;Antonietti,M.;Blechert,S.;Wang,X.Angew.Chem.Int.Edit.2012,51,3183.doi:10.1002/anie.v51.13
(23)Gupta,V.P.;Rawat,P.;Singh,R.N.;Tandon,P.Comput.Theor.Chem.2012,983,7.doi:10.1016/j.comptc.2011.12.006
(24)Kubota,Y.;Shibata,T.;Babamoto-Horiguchi,E.;Uehara,J.;Funabiki,K.;Matsumoto,S.;Ebihara,M.;Matsui,M.Tetrahedron2009,65,2506.doi:10.1016/j.tet.2009.01.053
(25)Khanmohammadi,H.;Abdollahi,A.Dyes Pigments2012,94,163.doi:10.1016/j.dyepig.2011.12.013
(26)Johnson,D.M.;Reybuck,S.E.;Lawton,R.G.;Rasmussen,P.G.Macromolecules2005,38,3615.doi:10.1021/ma047918l
(27)MacLachlan,M.J.;Park,M.K.;Thompson,L.K.Inorg.Chem.1996,35,5492.doi:10.1021/ic960237p
(28)Tabbal,M.;Christidis,T.;Isber,S.;Mérel,P.;Khakani,M.A.E.;Chaker,M.;Amassian,A.;Martinu,L.J.Appl.Phys.2005,98,044310.doi:10.1063/1.2009817
(29)Chen,X.B.;Shen,S.H.;Guo,L.;Mao,S.S.Chem.Rev.2010,110,6503.doi:10.1021/cr1001645