采用溶胶-凝胶法,以正硅酸乙酯和钛酸四正丁酯为复合溶胶前驱体,利用二乙醇胺控制正硅酸乙酯和钛酸四正丁酯的缩聚反应速率,通过原位生长法制备了N掺杂的碳纳米管/二氧化硅/二氧化钛(CNT/TiO2/SiO2)复合材料。采用扫描电镜(SEM)、光电子能谱(XPS)、粉末X射线衍射(XRD)等手段表征复合材料的表面形貌及结构,通过亚甲基蓝的光催化降解实验表征样品的光催化性能。结果表明:N掺杂的CNT/TiO2/SiO2复合材料较光催化剂商业二氧化钛(P25)具有更好的紫外光催化性能。此外,由二乙醇胺引入的N元素掺杂到TiO2晶格中,由于N和O的2p轨道杂化,使复合材料的禁带宽度收窄,产生可见光活性,从而使N掺杂CNT/TiO2/SiO2复合材料具有良好的可见光光催化性能。
Adopting sol-gel method,using ethyl orthosilicate and tetra-n-butyl titanate as precursors of composite sol,and using diethanolamine to control the polycondensation reaction of isopropyl titanate and ethyl orthosilicate,N-doped CNT/TiO2/SiO2 composites were prepared by in-situ growth method.Scanning electron microscope (SEM),photoelectron spectroscopy (XPS) and X-ray powder diffraction (XRD) were used to characterize the surface morphology and structure of the composite material,and characterized the photocatalytic performance of samples by photocatalytic degradation of methylene blue.The results shown that the N-doped CNT/TiO2/SiO2 had better UV photocatalytic performance than the photocatalyst P25.In addition,the N element introduced by diethanolamine was successfully doped into the TiO2 lattice.Due to the hybridization of the 2p orbitals of N and O,the band gap width of the material was narrowed and generated the visible light activity,thereby making N-doped CNT/TiO2/SiO2 composites had good visible light photocatalytic performance.
[1] Bailón-García E,Elmouwahidi A,Álvarez M A,et al.New carbon xerogel-TiO2 composites with high performance as visible-light photocatalysts for dye mineralization[J].Applied Catalysis B Environmental,2017,201:29-40.
[2] Pitre S P,Yoon T P,Scaiano J C.Titanium dioxide visible light photocatalysis:surface association enablesphotocatalysis with visible light irradiation[J].Chemical Communications,2017,53(31):4335-4338.
[3] Garusinghe U M,Raghuwanshi V S,Batchelor W,et al.Water resistant cellulose-titanium dioxide composites for photocatalysis[J].Scientific Reports,2018,8(1):2306-2318.
[4] Chen H,Nanayakkara C E,Grassian V H.Titanium dioxide photocatalysis in atmospheric chemistry[J].Chemical Reviews,2012,112(11):5919-5948.
[5] Zhu Z,Cai H,Sun D W.Titanium dioxide(TiO2) photocatalysis technology for nonthermal inactivation of microorganisms in foods[J].Trends in Food Science & Technology,2018,75:23-35.
[6] Mrowetz M,Balcerski W,Colussi A J,et al.Oxidative power of nitrogen-doped TiO2 photocatalysts under visible illumination[J].Physical Chemistry B,2004,108(45):17269-17273.
[7] Ramos-Delgado N A,Hinojosa-Reyes L,Guzman-Mar I L,et al.Synthesis by sol-gel of WO3/TiO2 for solar photocatalytic degradation of malathion pesticide[J].Catalysis Today,2013,209:35-40.
[8] Pelaez M,Nolan N T,Pillai S C,et al.A review on the visible light active titanium dioxide photocatalysts for environmental applications[J].Applied Catalysis B Environmental,2012,125:331-349.
[9] Grujiė BrojėAčin M,Armakoviė S,Tomiė N,et al.Surface modification of sol-gel synthesized TiO2 nanoparticles induced by La-doping[J].Materials Characterization,2014,88(2):30-41.
[10] Park S K,Yun T K,Bae J Y.Combined embedding of N/F-doping and CaCO3 surface modification in the TiO2 photoanode for dye-sensitized solar cells[J].Nanoscience & Nanotechnology,2016,16(3):2571-2575.
[11] Hung H C,Lin Y J,Ke Z Y.Interface modification of MoS2:TiO2 counter electrode/electrolyte in dyesensitized solar cells by doping with different Co contents[J].Journal of Materials Science,2016,27(5):5059-5063.
[12] Dehdouh H,Bensaha R,Zergoug M.Structural modification,photoluminescence,and magnetic property enhancement with Er3+doping,of sol-gel TiO2 thin films[J].Materials Research Express,2017,4(8):086408.
[13] Yang G D,Jiang Z,Shi H H,et al.Preparation of highly visible-light active N-doped TiO2 photocatalyst[J].Materials Chemistry,2010,20(25):5301-5309.
[14] Yu H F.Photocatalytic abilities of gel-derived P-doped TiO2[J].The Physics and Chemistry of Solids,2007,68(4):600-607.
[15] Liu G,Han C,Pelaez M,et al.Synthesis,characterization and photocatalytic evaluation of visible light activated C-doped TiO2 nanoparticles[J].Nanotechnology,2012,23(29):294003.
[16] Xia H L,Zhuang H S,Zhang X T,et al.Photocatalytic activity of lanthanum and sulfur Co-doped TiO2 photocatalyst under visible light[J].Journal of Wuhan University of Technology,2008,23(4):41-45.
[17] Zhao Wei,Ma Wanhong,Chen Chuncheng,et al.Efficient degradation of toxic organic pollutants with Ni2O3/TiO2-xBx under visible irradiation[J].The American Chemical Society,2004,126(15):4782-4783.
[18] Yu J,Yang Y L,Fan R Q,et al.Mechanism of performance enhancement via fluorine doped titanium dioxide nanoparticles in dye sensitized solar cells[J].Fluorine Chemistry,2015,176:71-77.
[19] Wu D,Long M,Cai W,et al.Low temperature hydrothermal synthesis of N-doped TiO2 photocatalyst with high visible-light activity[J].Alloys and Compounds,2010,502(2):289-294.
[20] Luo H,Takata T,Lee Y,et al.Photocatalytic activity enhancing for titanium dioxide by Co-doping with bromine and chlorine[J].Chemistry of Materials,2004,16(5):846-849.
[21] Hou Q,Zheng Y,Chen J F,et al.Visible-light-response iodine-doped titanium dioxide nanocrystals for dye-sensitized solar cells[J].Materials Chemistry,2011,21(11):3877-3883.
[22] 浮艳婷,盛永刚.CVD法制备CNT-TiO2/SiO2复合材料[J].辽宁化工,2016,45(2):131-134.
[23] Benito N,Palacio C.Growth of Ti-O-Si mixed oxides by reactive ion-beam mixing of Ti/Si interfaces[J].Journal of Physics D:Applied Physics,2014,47(1):5308.
[24] 张晓艳,崔晓莉.C-N共掺杂纳米TiO2的制备及其光催化制氢活性[J].物理化学学报,2009,25(9):1829-1834.
[25] Wang J,Zhu W,Zhang Y,et al.An efficient two-step technique for nitrogen-doped titanium dioxide synthesizing:visible-light-induced photodecomposition of methylene blue[J].Physical Chemistry C,2007,111(2):1010-1014.
[26] Weng L T,Poleunis C,Bertrand P.Sizing removal and functionalization of the carbon fiber surface studied by combined TOF SIMS and XPS[J].Adhesion Science & Technology,1995,9(7):859-871.
[27] Lin Z,Orlov A,Lambert R M,et al.New insights into the origin of visible light photocatalytic activity of nitrogen-doped and oxygen-deficient anatase TiO2[J].Physical Chemistry B,2005,109(44):20948-20952.
[28] Zhang H Z,Banfield J F.Understanding polymorphic phase transformation behavior during growth of nanocrystalline aggregates:insights from TiO2[J].Physical Chemistry B,2000,104:3481-3487.
