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Tạo ra khiếm khuyết, chuyển giao d-d và giảm khoảng cách năng lượng trong nanoparticle TiO2 doped Cu
Tóm tắt
TiO2 bị dop Cu2+ kích thích sự hình thành pha brookite cùng với anatase. Việc bổ sung Cu2+ tạo ra các khiếm khuyết cấu trúc trong TiO2. Bằng chứng trực tiếp là những đỉnh khuếch tán yếu và rộng. Các đỉnh Raman của TiO2 dop cũng rộng và bị dịch sang tần số cao hơn. TiO2 nguyên chất thể hiện sự hấp thụ trong vùng UV, vị trí của nó bị dịch về phía vùng khả kiến khi bổ sung Cu vào. Các đỉnh hấp thụ khả kiến xuất hiện do sự chuyển giao d-d của Cu2+ trong môi trường tinh thể của TiO2. Việc bổ sung Cu2+ làm biến dạng cấu trúc cục bộ của TiO2, dẫn đến mất đối xứng bát diện xung quanh Cu2+. Biến dạng Jahn-Teller tách biệt trạng thái 2Eg và 2T2g của Cu2+ thành nhiều trạng thái d. Sự tương tác của ánh sáng kích thích electron từ trạng thái cơ bản lên nhiều trạng thái kích thích, tạo ra các đỉnh hấp thụ khả kiến trong khung của TiO2. Những trạng thái d của Cu2+ và khiếm khuyết oxy tạo ra các trạng thái dải, qua đó thúc đẩy quá trình chuyển giao điện tử đến những mức này và dẫn đến việc giảm khoảng cách năng lượng của TiO2. Một xác nhận trực tiếp là sự tăng cường cường độ năng lượng Urbach với sự giảm đi về khoảng cách năng lượng của TiO2 dop.
Từ khóa
Tài liệu tham khảo
Hashimoto K, Irie H, Fujishima A: TiO 2 photocatalysis: a historical overview and future prospects. Jpn. J. Appl. Phys. 2005, 44: 8269–8285. 10.1143/JJAP.44.8269
Ni Y, Zhu Y, Ma X: A simple solution combustion route for the preparation of metal-doped TiO 2 nanoparticles and their photocatalytic degradation properties. Dalton Trans. 2011, 40: 3689–3694. 10.1039/c0dt01534b
Sahu M, Biswas P: Single-step processing of copper-doped titania nanomaterials in a flame aerosol reactor. Nanoscale Res Lett. 2011, 6: 441. 10.1186/1556-276X-6-441
Xiong LB, Li JL, Yang B, Yu Y: Ti3+ in the surface of titanium dioxide: generation, properties and photocatalytic application. J. Nanomaterials. 2012, 2012: 1–13.
Liu G, Yang HG, Wang X, Cheng L, Lu H, Wang L, Lu GQ, Cheng HM: Enhanced photoactivity of oxygen deficient anatase TiO2 with dominant 001 facets. J. Phys. Chem. C. 2009, 113: 21784–21788. 10.1021/jp907749r
Pal M, Pal U, Jimenez J, Rodriguez F: Effect of crystallization and dopant concentration on the emission behaviour of TiO 2 :Eu nanophosphors. Nanoscale Res Lett. 2012, 7: 1–12. 10.1186/1556-276X-7-1
Meng F, Hong Z, Amdt J, Li M, Zhi M, Yang F: Visible light photocatalytic activity of nitrogen-doped La 2 Ti 2 O 7 nanosheets originating from band gap narrowing. Nano Research 2012, 5: 213–221. 10.1007/s12274-012-0201-x
Cheng C, Sun Y: Carbon doped TiO 2 nanowire arrays with improved photoelectrochemical water splitting performance. Appl. Surf. Sci. 2012, 263: 273–276.
Meng F, Li J, Hong Z, Zhi M, Sakla A, Xiang C, Wu N: Photocatalytic generation of hydrogen with visible-light nitrogen-doped lanthanum titanium oxides. Catalysis Today. 2013, 199: 48–52.
Choi W, Termin A, Hoffman MR: The role of metal ion dopants in quantum sized TiO 2 : correlation between photoreactivity and charge carrier recombination dynamics. J. Phys. Chem. 1994, 98: 13669–13679. 10.1021/j100102a038
Jaimy BK, Safeena VP, Ghosh S, Hebalkar NY, Warrier KGK: Photocatalytic activity enhancement in doped titanium dioxide by crystal defects. Dalton Trans. 2012, 41: 4824–4832. 10.1039/c2dt12018f
Cao FF, Xin S, Guo YG, Wan LJ: Wet chemical synthesis of Cu/TiO 2 nanocomposites with integrated nano-current-collectors as high-rate anode materials in lithium-ion batteries. Phys. Chem. Chem. Phys. 2011, 13: 2014–2020. 10.1039/c0cp01119c
Arana J, Rodriguez JMD, Melian JAH, Rendon ET, Diaz OG: Role of Pd and Cu in gas phase alcohols photocatalytic degradation with doped TiO 2 . J. Photochem. Photobiol. A. 2005, 174: 7–14. 10.1016/j.jphotochem.2005.03.003
Manivel A, Naveenraj S, Kumar S, Selvam P, Anandan S: CuO-TiO 2 nanocatalyst for photodegradation of acid red 88 in aqueous solution. Sci. Adv. Mater. 2010, 2: 51–57. 10.1166/sam.2010.1071
Li G, Dimitrijevic NM, Chen L, Rajh T: Role of surface/interfacial Cu2+sites in the photocatalytic activity of coupled CuO-TiO 2 nanocomposites. J. Phys. Chem. C. 2008, 112: 19040–19044.
Wang RSH, Feng J, Hu X, Lock PY: Discoloration and mineralization of non-biodegradable Azo dye orange II by copper-doped TiO 2 nanocatalysts. J. Environ. Sci. Health, Part A: Toxic/Hazard. Subst. Environ. Eng 2004, 39: 2583–2595. 10.1081/ESE-200027013
Wang B, Zhao YD, Hu L, Cao JS, Gao FL, Liu Y, Wang LJ: Improved and excellent CO sensing properties of Cu-doped TiO 2 nanofibers. Chinese Science Bulletin 2010, 55: 228–232. 10.1007/s11434-009-0727-9
Nian JN, Chen SA, Tsai CC, Teng H: Structural feature and catalytic performance of Cu species distributed over TiO 2 nanotubes. J. Phys. Chem. B. 2006, 110: 25817–25824. 10.1021/jp064209w
Slamet , Nasution HW, Purnama E, Kosela S, Gunlazuardi J: Photocatalytic reduction of CO 2 on copper-doped titania catalysts prepared by improved-impregnation method. Catal. Commun. 2005, 6: 313–319. 10.1016/j.catcom.2005.01.011
Baghriche O, Rtimi S, Pulgarin C, Sanjines R, Kiwi J: Effect of the spectral properties of TiO 2 , Cu, TiO 2 /Cu sputtered films on the bacterial inactivation under low intensity actinic light. J. Photochem. Photobiol., A 2013, 251: 50–56.
So WW, Park SB, Kim KJ, Shin CH, Moon SJ: The crystalline phase stability of titania particles prepared at room temperature by the sol–gel method. J. Mater. Sci. 2001, 36: 4299–4305. 10.1023/A:1017955408308
Zhang WF, He YL, Zhang MS, Yin Z, Chen Q: Raman scattering study of anatase TiO 2 nanocrystals. J. Phys. D: Appl. Phys. 2000, 33: 912–916. 10.1088/0022-3727/33/8/305
Choudhury B, Choudhury A: Dopant induced changes in structural and optical properties of Cr doped TiO 2 nanoparticles. Mater. Chem. Phys. 2012, 132: 1112–1118. 10.1016/j.matchemphys.2011.12.083
Tian F, Zhang Y, Zhang J, Pan C: Raman spectroscopy: a new approach to measure the percentage of anatase TiO 2 exposed (001) facets. J. Phys. Chem. C. 2012, 116: 7515–7519. 10.1021/jp301256h
Duhalde S, Vignolo MF, Golmar F, Chiliotte C, Rodriguez CE, Errico LA, Cabrera AF, Renteria M, Sanchez FH, Weissmann M: Appearance of room-temperature ferromagnetism in Cu-doped TiO 2− δ films. Phys. Rev. B 2005,72(R):161313.
Parker JC, Siegel RW: Calibration of the Raman spectrum to the oxygen stoichiometry of nanophase TiO 2 . Appl. Phys. Lett. 1990, 57: 943–945. 10.1063/1.104274
Xue X, Ji W, Mao Z, Mao H, Wang Y, Wang X, Ruan W, Zhao B, Lombardi JR: Raman investigation of nanosized TiO 2 : effect of crystallite size and phonon confinement. J. Phys. Chem. C. 2012, 116: 8792–8797.
Baltazar P, Lara V, Cordoba G, Arroyo R: Kinetics of the amorphous anatase phase transformation copper doped titanium dioxide. J. Sol–gel Sci Tech 2006, 37: 129–133. 10.1007/s10971-006-6432-0
Choudhury B, Borah B, Choudhury A: Ce-Nd codoping effect on the structural and optical properties of TiO 2 nanoparticles. Mater. Sci. Eng B 2013, 178: 239–247. 10.1016/j.mseb.2012.11.017
Nagao Y, Yoshikawa A, Koumot K, Kato T, Ikuhara Y, Ohta H: Experimental characterization of the electronic structure of anatase TiO 2 : thermopower modulation. Appl. Phys. Lett. 2010, 97: 172112. 10.1063/1.3507898
Komova OV, Simakov AV, Rogov VA, Kochubei DI, Odegova GV, Kriventsov VV, Puakshitis EA, Ushakov VA, Sazonova NN, Nikoro TA: Investigation of the state of copper in supported copper-titania oxide catalysts. J. Mol. Catal. A: Chem. 2000, 161: 191–204. 10.1016/S1381-1169(00)00342-3
Liu M, Qiu X, Miyauchi M, Hashimoto K: Cu(II) oxide amorphous nanoclusters grafted Ti3+ self-doped TiO 2 : an efficient visible light photocatalyst. Chem. Mater. 2011, 23: 5582–5586.
Irie H, Miura S, Kamiya K, Hashimoto K: Efficient visible light sensitive photocatalysts: grafting of Cu (II) ion onto TiO 2 and WO 3 photocatalysts. Chem Phys Lett 2008, 457: 202–205. 10.1016/j.cplett.2008.04.006
Qiu X, Miyauchi M, Sunada K, Minoshima M, Liu M, Lu Y, Li D, Shimodaira Y, Hosogi Y, Kuroda Y, Hashimoto K: Hybrid Cu x O/TiO 2 nanocomposite as risk reduction materials in indoor environments. ACS Nano 2012, 6: 1609–1618. 10.1021/nn2045888
Ramadevudu G, Shareefuddin N, Bai S, Rao ML, Chary MN: Electron paramagnetic resonance and optical absorption studies of Cu2+ spin probe in MgO-Na 2 O-B 2 O 3 ternary glasses. J. Non-Cryst. Solids 2000, 278: 205–212. 10.1016/S0022-3093(00)00255-6
Somasekharam V, Siva Prasad P, Ramesh K, Reddy YP: Electronic spectra of VO2+ and Cu2+ ions in rubidium zinc sulphate hexahydrate. Physica Scripta. 1986, 33: 169–172. 10.1088/0031-8949/33/2/014
Kamalaker V, Upender G, Prasad M, Mouli VC: Infrared, ESR and optical absorption studies of Cu2+ ions doped in TeO 2 -ZnO-NaF glass system. Indian J. Pure Appl. Phys. 2010, 48: 709–715.
Chakradhar S, Ramesh KP, Rao JL, Ramakrishna J: Mixed alkali effect in borate glasses-electron paramagnetic resonance and optical absorption studies in Cu2+ doped xNa 2 O-(3-x) K 2 O-70B 2 O 3 glasses. J. Phys. Condens. Matter. 2003, 15: 1469. 10.1088/0953-8984/15/9/311
Lalitha K, Sadanandam G, Kumari VD, Subrahmanyam M, Sreedhar B, Hebalkar NY: Highly stabilized and finely dispersed Cu 2 O/TiO 2 : a promising visible sensitive photocatalyst for continuous production of hydrogen from glycerol: water mixtures. J. Phys. Chem. C. 2010, 114: 22181–22189. 10.1021/jp107405u
Serpone N: Is the band gap of pristine TiO 2 narrowed by anion and cation doping of titanium dioxide in second generation photocatalysts? J. Phys. Chem. B. 2006, 110: 24287–24293. 10.1021/jp065659r
Boubaker K: A physical explanation to the controversial Urbach tailing universality. Eur. Phys. J. Plus 2011, 126: 10.
Choudhury B, Borah B, Choudhury A: Extending photocatalytic activity of TiO 2 nanoparticles to visible region of illumination by doping of cerium. Photochem. Photobiol. 2012, 88: 257–264. 10.1111/j.1751-1097.2011.01064.x