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系統識別號 U0026-3007201414383900
論文名稱(中文) 濺鍍陣列式HfO2-TiO2奈米柱光觸媒
論文名稱(英文) Photocatalytic Applications of Nanocomposites of HfO2 - TiO2 Nanorod Arrays Using Sputtering
校院名稱 成功大學
系所名稱(中) 材料科學及工程學系
系所名稱(英) Department of Materials Science and Engineering
學年度 102
學期 2
出版年 103
研究生(中文) 馮皓哲
研究生(英文) Hao-Che Feng
學號 n56014384
學位類別 碩士
語文別 英文
論文頁數 66頁
口試委員 指導教授-張高碩
口試委員-丁志明
口試委員-陳貞夙
口試委員-梁元彰
中文關鍵字 二氧化鉿及二氧化鈦奈米柱  反應性濺鍍法  載子捕捉  光催化及光電化學特性 
英文關鍵字 nanocomposites of HfO2-TiO2 nanorod arrays  reactive sputtering  charge trapping  photocatalysis  photoelectrochemical cell 
學科別分類
中文摘要 這份研究指出高介電材料(二氧化鉿)的最新應用方向,利用其二氧化鉿的缺陷來捕捉載子進而達成光協同作用以利於分解有機汙染物。在實驗過程中,濺鍍陣列式二氧化鉿及二氧化鈦奈米柱來進行研究分析。
因一維材料能有效地增加載子傳遞,故製備二氧化鉿陣列式奈米柱,其彼此間距最大為500nm。而最佳二氧化鉿及二氧化鈦的協同效應為四層結構,二氧化鉿及二氧化鈦的單層厚度分別為375nm及100nm。實驗上發現,在紫外光(30瓦)的照射環境下,濃度為200ppm的樣品經90分鐘後可降解約70%的亞甲基藍水溶液(5ppm)。
為了更完善地此詮釋光協同效應,以二氧化鉿及二氧化鈦的能帶結構圖作為說明,在二氧化鈦產生的光電子會被二氧化鉿奈米柱內的氧(VO2+)缺陷捕捉,而被缺陷的電子會再躍遷到二氧化鉿的導帶。電子捕獲效應也由光致發光圖譜中發現其被捕捉的電子,會在二氧化鉿的氧缺陷(VO2+)產生再結合。除此之外,其光電化學特性也是良好的。
英文摘要 This research reports a novel application of high-k material (HfO2) to photocatalysis for the first time by enabling the defects in HfO2 to trap charge carriers to achieve synergistic photo-decomposition of organic pollutants (methylene blue).
A comprehensive investigation into the fabrication of nanocomposites of HfO2-TiO2 nanorod arrays using reactive sputtering was conducted. Well oriented and a maximum separation of approximately 500 nm of HfO2 nanorods were achieved, which enhanced charge carrier transport along the 1D nanoarchitecture. The optimal coupling between HfO2 and TiO2 for photocatalysis was identified as 4 layered HfO2/TiO2 nanorods with thicknesses of 375nm/100nm for each layer. The sample (200 ppm) was found to photodegrade 70 % of a methylene blue solution (5 ppm) in 90 minutes under 30 W UV irradiation.
The synergistic photocatalytic effect was interpreted using the energy band diagrams of the HfO2-TiO2 system and attributed to the circumstance that the photogenerated electrons in TiO2 were trapped in the gap state of VO2+ in HfO2 nanorods, and then pumped into the conduction band of HfO2. The trapping mechanism was further analyzed by performing the measurement of photoluminescence spectroscopy. Another interesting application of the system to a photoelectrochemical reaction was demonstrated as well.
論文目次 摘要.................. I
Abstract ................. II
誌謝..................III
Content .................IV
Figure Content................VI
Table Content ................VIII
Chap 1 Introduction ...............1
1.1 Motivation ..............1
1.2 Background...............1
1.2.1 Environmental pollution...........1
1.2.2 Solar Energy .............2
1.2.3 Applications of solar energy...........2
1.3 Photocatalyst...............4
1.3.1 Popular photocatalysts............4
1.3.2 Promising structures for photocatalysts .........6
1.4 TiO2 photocatalyst ..............7
1.4.1 Crystal structures and properties of TiO2 .........8
1.4.2 Disadvantages of TiO2 for photocatalysis ........8
1.5 Fabricarion of TiO2.............9
1.5.1 Comparison of fabrication methods .........10
1.5.2 Review of physical vapor deposition (PVD)........11
1.5.3 Nanorod fabrication of sputtering ..........13
1.6 TiO2-based nanocomposites............15
1.7 New Application of Hafnium oxide (HfO2): a photocatalyst .....15
1.7.1 Crystal structure and electrical properties of HfO2 ......15
1.7.2 Defects in HfO2 ............16
1.8 Nanocomposite of HfO2-TiO2 ..........17
1.8.1 Literature review ............17
1.8.2 Synergistic photocatalysis ..........17
1.9 Research objectives ............19
Chap 2 Experiment ..............20
2.1 Experimental materials.............20
2.1.1 Sputtering target .............20
2.1.2 Substrate .............20
2.1.3 Sputtering gas .............20
2.1.4 Annealing gas .............20
2.2 Experimental chemicals............21
2.3 Experimental equipment...........21
2.3.1 Magnetron reactive sputtering..........21
2.3.2 Tube furnace .............23
2.3.3 FIB (Focus ion beam)...........24
2.4 Characterizations ..............24
2.5 Photodegradation..............27
2.6 Photoelectrochemical (PEC) cell..........27
Chap 3 Results and Discussions ............29
3.1 Manufacturing of HfO2 nanorod structures........29
3.1.1 Direct process to make HfO2 nanorods ........29
3.1.2. Indirect process to make HfO2 nanorods .......34
3.2 Structure analysis of HfO2 nanorods: XRD and TEM .......38
3.3 Manufacturing of TiO2 nanorod structure .........40
3.4 Nanocomposite of HfO2 and TiO2 nanorods.........41
3.4.1 TEM analysis of nanocomposite of HfO2-TiO2 nanorods......44
3.5. Photocatalytic properties of nanocomposite of HfO2 -TiO2 nanorods.....46
3.5.1 The effect of different pH values..........46
3.5.2 Photocatalytic properties of different cycles of nanocomposite of HfO2 -TiO2 nanorods. .............47
3.5.3 Further photocatalytic analysis of the 4x nanocomposite of HfO2 -TiO2 nanorods ..............48
3.5.4 The effects of forming gas (90% N2+10% H2) and oxidation....49
3.6 Model of charge trapped effect...........50
3.7 photoelectrochemicalcurrent measurement ........51
3.8 Photoluminescenct (PL) spectroscopy .........53
Chap 4 Conclusions and Future work............55
4.1 HfO2 nanorods made by sputtering ..........55
4.2 Nanocomposites of HfO2-TiO2 nanorod arrays........55
4.3 Characterizations of nanocomposites HfO2-TiO2 nanorod arrays....55
4.4 Synergistic reaction of nanocomposites HfO2-TiO2 nanorod arrays....56
4.5 Performance of the PEC cell of nanocomposites HfO2-TiO2 nanorod arrays..56
4.6 Future work ..............56
References ................58
參考文獻 [1] G. D. Wilk, R. M. Wallace and J. M. Anthony, High-k gate dielectrics: Current status and materials properties considerations, J. Appl. Phys., 89: p. 5243-5275 (2001).
[2] P. A. Packan, Pushing the Limits, Science, 285: p. 2079-2081 (1999).
[3] J. V. Houdt, High-K Materials For Nonvolatile Memory Applications, IRPS, San Jose, April, (2005).
[4] A. I. Kingon, J.-P. Maria, S. K. Streiffer, Alternative dielectrics to silicon dioxide for memory and logic devices, Nature, 406: p. 1032-1038 (2000).
[5] WEO team, World Energy Outlook, International Energy Agency, London, (2013).
[6] K. R. Lang, The Cambridge Guide to the Solar System, Cambridge University Press, United Kingdom, (2011).
[7] A. Goetzberger, V. U. Hoffmann, Photovoltaic Solar Energy Generation, Springer, Germany, (2005).
[8] R. B. Bergmann, Crystalline Si thin-film solar cells: a review. Appl. Phys. A. 69: p. 187-194 (1999).
[9] B. Shin, O. Gunawan, Y. Zhu, N. A. Bojarczuk, S. J. Chey and S. Guha, Thin film solar cell with 8.4% power conversion efficiency using an earth-abundant Cu2ZnSnS4 absorber, Prog. Photovolt: Res. Appl, 21: p. 72-76 (2013).
[10] D. Aaron R. Barkhouse, O. Gunawan, T. Gokmen, T. K. Todorov and David B. Mitzi, Device characteristics of a 10.1% hydrazine-processed Cu2ZnSn(Se,S)4 solar cell, Prog. Photovolt: Res. Appl., 20: p. 6-11 (2012).
[11] K. Hashimoto, H. Irie and A. Fujishima, TiO2 Photocatalysis: A Historical 58
overview and Future Prospects, Jpn. J. Appl. Phys., Part 1, 44: p. 8269-8285 (2005).
[12] D. Roberta and S. Malato, Solar photocatalysis: a clean process for water detoxification, Sci. Total Environ, 291: p. 85-97 (2002).
[13] Z. Michalcik, M. Horakova, P. Spatenka, S. Klementova, M. Zlamal and N. Martin, Photocatalytic Activity of Nanostructured Titanium Dioxide Thin Films, Int. J. Photenergy, 2012: p. 8 (2012).
[14] Z. Li, L. Xing, N. Zhang, Y. Yang and Z. Zhang, Preparation and Photocatalytic Property of TiO2 Columnar Nanostructure Films, Mater. Trans., 52: p. 1939-1942 (2011).
[15] X. Bai, L. Wang, R. Zong, Y. Lv, Y. Sun and Y. Zhu, Performance Enhancement of ZnO Photocatalyst via Synergic Effect of Surface Oxygen Defect and Graphene Hybridization, Langmuir, 29: p. 3097-3105 (2013).
[16] M. Niu, F. Huang, L. Cui, P. Huang, Y. Yu and Y. Wang, Hydrothermal Synthesis, Structural Characteristics, and Enhanced Photocatalysis of SnO2/α-Fe2O3 Semiconductor Nanoheterostructures, ACSNano, 4: p. 681-688 (2010).
[17] R. Ahmed, G. Will, J. Bell and H. Wang, Size-dependent photodegradation of CdS particles deposited onto TiO2 mesoporous films by SILAR method, J. Nanopart Res., 14: p. 1140-1153 (2012).
[18] S. Rengaraj, S. H. Jee, S. Venkataraj, Y. Kim, S. Vijayalakshmi, E. Repo, A. Koistinen and M. Sillanp, CdS Microspheres Composed of Nanocrystals and
Their Photocatalytic Activity, J. Nanosci. Nanotechnol., 11: p. 1-10 (2011).
[19] J.-S. Hu, L.-L. Ren, Y.-G. Guo, H.- P. Liang, A.-M. Cao, L.-J. Wan and C.-L. Bai, Mass Production and High Photocatalytic Activity of ZnS Nanoporous 59
Nanoparticles, Angew. Chem., 117: p. 1295-1299 (2005).
[20] M. R. Hoffmann, S. T. Martin, W. Choi and D. W. Bahnemann, Environmental Applications of Semiconductor Photocatalysis, Chem. Rev., 95: p. 69-96 (1995).
[21] Ü. Özgür, Y. I. Alivov, C. Liu, A. Teke, M. A. Reshchikov, S. Doan, V. Avrutin, S.-J. Cho and H. Morkoç, A comprehensive review of ZnO materials and devices, J. Appl. Phys., 98: p.041301-11 – 041301-103 (2005).
[22] H.-F. Lin, S.-C. Liao and S.-W. Hung, The dc thermal plasma synthesis of ZnO nanoparticles for visible-light photocatalyst, J. Photochem. Photobiol., A, 174: p. 82–87 (2005).
[23] M. Hara, T. Kondo, M. Komoda, S. Ikeda, K. Shinohara, A. Tanaka, J. N. Kondo and K. Domen, Cu2O as a photocatalyst for overall water splitting under visible light irradiation, Chem. Commun., p. 357-358 (1998).
[24] T. K. Townsend, E. M. Sabio, N. D. Browning and F. E. Osterloh, Photocatalytic water oxidation with suspended alpha-Fe2O3 particles-effects of nanoscaling, Energy Environ. Sci., 4: p. 4270-4275 (2011).
[25] D. Yang, H. Liu, Z. Zheng, Y. Yuan, J.-c. Zhao, E. R. Waclawik, X. Ke and H. Zhu, An Efficient Photocatalyst Structure: TiO2(B) Nanofibers with a Shell of Anatase Nanocrystals, J. AM. CHEM. SOC., 131: p. 17885-17893 (2009).
[26] H. M. Fan, G. J. You, Y. Li, Z. Zheng, H. R. Tan, Z. X. Shen, S. H. Tang and Y. P. Feng, Shape-Controlled Synthesis of Single-Crystalline Fe2O3 Hollow Nanocrystals and Their Tunable Optical Properties, J. Phys. Chem. C, 113: p. 9928-9935 (2009).
[27] Y. Hou, X. Li, X. Zou, X. Quan and G. Chen, Photoeletrocatalytic Activity of a Cu2O-Loaded Self-Organized Highly Oriented TiO2 Nanotube Array
60
Electrode for 4-Chlorophenol Degradation, Environ. Sci. Technol., 43: p.858-863 (2009).
[28] C. J. Murphy and N. R. Jana, Controlling the Aspect Ratio of Inorganic Nanorods and Nanowires, Adv. Mater., 14: p. 80-82 (2002).
[29] Z.-A. Lin, W.-C. Lu, C.-Y. Wu and K.-S. Chang, Facile fabrication and tuning of TiO2 nanoarchitectured morphology using magnetron sputtering and its applications to photocatalysis, Accepted, Ceram. Int. (2014).
[30] W. Choi, Pure and modified TiO2 photocatalysts and their environmental applications, Catal. Surv. Asia., 10: p. 16-28 (2006).
[31] D. A. H. Hanaor, G. Triani, and C. C. Sorrell, Morphology and Photocatalytic Activity of Highly Oriented Mixed Phase Titanium Dioxide Thin Films, Surf. Coat. Technol., 205: p. 3659-3664 (2011).
[32] A. Zaleska, Doped-TiO2: A Review, RECENT PAT Eng., 2: p. 157-164 (2008).
[33] M. V. Dozzi and E. Selli, Doping TiO2 with p-block elements: Effects on photocatalytic activity, J. Photochem. Photobiol., C, 14: p. 13-28 (2013).
[34] V. Stengl, J. Henych, P. Vomacka and M. Slusna, Doping of TiO2–GO and TiO2–rGO with Noble Metals: Synthesis,Characterization and Photocatalytic Performance for Azo Dye Discoloration, Photochem. Photobiol., 89: p. 1038-1046 (2013).
[35] M. Salari, Enhancement of the capacitance in TiO2 nanotubes through controlled introduction of oxygen vacancies, J. Mater. Chem., 21: p. 5128-5133 (2011).
[36] E. M. Ceresa, An ESR study on the photoreactivity of TiO2 pigments, J. Mater. Sci., 18: p. 289-294 (1983).
61
[37] M. M. Byranvanda, A. N. Kharata, L. Fatholahib and Z. M. Beiranvandc, A Review on Synthesis of Nano-TiO2 via Different Methods, JNS, 3: p. 1-9 (2013).
[38] J. Yan and F. Zhou, TiO2 nanotubes: Structure optimization for solar
Cells, J. Mater. Chem., 21: p. 9406-9418 (2011).
[39] A. Weir, P. Westerhoff, L. Fabricius, K. Hristovski and N. Goetz, Titanium Dioxide Nanoparticles in Food and Personal Care Products, Environ. Sci. Technol., 46: p.2242-2250 (2012).
[40] J. S. Lee, K. H. You and C. B. Park, Highly Photoactive, Low Bandgap TiO2 Nanoparticles Wrapped by Graphene, Adv. Mater., 24: p. 1084-1088 (2012).
[41] J. Wang, Z. Wang, B. Huang, Y. Ma, Y. Liu, X. Qin, X. Zhang and Y. Dai, Oxygen Vacancy Induced Band-Gap Narrowing and Enhanced Visible Light Photocatalytic Activity of ZnO, Appl. Mater. Interfaces, 4: p. 4024-4030 (2012).
[42] C.-T. Dinh, T.-D. Nguyen, F. Kleitz and T.-O. Do, Shape-Controlled Synthesis of Highly Crystalline Titania Nanocrystals. ACSNano, 3: p. 3737-3743 (2009).
[43] D. Wu, M. Longa, W. Caia, C. Chenb and Y. Wub, Low temperature hydrothermal synthesis of N-doped TiO2 photocatalyst with high visible-light activity, J. Alloys Compd., 502: p. 289-294 (2010).
[44] X.-W. Bao, S.-S. Yan, F. Chen and J.-l. Zhang, Preparation of TiO2 photocatalyst by hydrothermal method from aqueous peroxotitanium acid gel, Mater. Lett., 59: p. 412-415 (2005).
[45] J.-M. Wu, H. C. Shih, W.-T. Wu, Y.-K. Tseng and I-C. Chen, Thermal evaporation growth and the luminescence property of TiO2 nanowires, J. Cryst. Growth., 281: p. 384-390 (2005).
[46] R. Shao, C. Wang, D. E. McCready, T. C. Droubay and S. A. Chambers,
62
Growth and structure of MBE grown TiO2 anatase films with rutile nano-crystallites, Surf. Sci., 601: p. 1582-1589 (2007).
[47] M. Yamagishi, S. Kuriki, P. K. Song and Y. Shigesato, Thin film TiO2 photocatalyst deposited by reactive magnetron sputtering, Thin Solid Films, 442: p. 227-231 (2003).
[48] V. V. Kislyuk and O. P. Dimitriev, Nanorods and Nanotubes for Solar Cells, J. Nanosci. Nanotechnol., 8: p. 131-148 (2008).
[49] P. Kajitvichyanukul, J. Ananpattarachai and S. Pongpom, Sol–gel preparation and properties study of TiO2 thin film for photocatalytic reduction of chromium(VI) in photocatalysis process, Sci. Technol. Adv. Mat., 6: p. 352-358 (2005).
[50] M.-J. Kim, S.-H. Park and Y.-D Huh, Photocatalytic Activities of Hydrothermally Synthesized Zn2SnO4, Bull. Korean Chem. Soc., 32: p. 1757-1760 (2011).
[51] A. Mubarak, E. Hamzah and M. R. M. Toff, Review Of Physical Vapor Deposition (PVD)Techniques For Hard Coating, Jurnal Mekanikal, 20: p. 42-51 (2005).
[52] Y. Xu and X.-T. Yan, Chemical Vapour Deposition An Integrated Engineering Design for Advanced Materials, Springer, London, (2010).
[53] Y.-P. Zhao, D.-X. Ye, G.-C. Wan and T.-M. Lu, Designing Nanostructures by Glancing Angle Deposition, Proc. of SPIE, 5219: p. 59-73 (2003).
[54] J. A. Thornton, Influence of apparatus geometry and deposition conditions on the structure and topography of thick sputtered coatings, J. Vac. Sci. Technol., 11: p. 666-670 (1974).
[55] M. D. Driessen, A. L. Goodman, T. M. Miller, G. A. Zaharias and V. H. 63
Grassian, Gas-Phase Photooxidation of Trichloroethylene on TiO2 and ZnO: Influence of
Trichloroethylene Pressure, Oxygen Pressure, and the Photocatalyst Surface on the Product Distribution, J. Phys. Chem. B, 102: p. 549-556 (1998).
[56] M. Wang, L. Sun, Z. Lin, J. Cai, K. Xie and C. Lin, p–n Heterojunction photoelectrodes composed of Cu2O-loaded TiO2 nanotube arrays with enhanced photoelectrochemical and photoelectrocatalytic activities, Energy Environ. Sci., 6: p. 1211-1220 (2013).
[57] H. Zhao, W. Fu, H. Yang, Y. Xu, W. Zhao, Y. Zhang, H. Chen, Q. Jing, X. Qi, J. Cao, X. Zhou and Y. Li, Synthesis and characterization of TiO2/Fe2O3 core–shell nanocomposition film and their photoelectrochemical property, Appl. Surf. Sci., 257: p. 8778-8783 (2011).
[58] J. Robertson, High dielectric constant oxides, Eur. Phys. J. Appl. Phys., 28: p. 265-291 (2004).
[59] A. Callegari, E. Cartier, M. Gribelyuk, H. F. Okorn-Schmidt and T. Zabel, Physical and electrical characterization of Hafnium oxide and Hafnium silicate sputtered films, J. Appl. Phys., 90: p. 6466-6475 (2001).
[60] A. S. Foster, F. Lopez Gejo, A. L. Shluger and R. M. Nieminen, Vacancy and interstitial defects in hafnia, Phys. Rev. B, 65: p. 174117-1 – 174117-13 (2002).
[61] J. H. Choi, Y. Mao and J.P. Chang, Development of hafnium based high-k materials—A review, Mater. Sci. Eng., R, 72: p. 97-136 (2011).
[62] S. Dutta, Sivaramakrishnan R., S. Gopalan and B. Shankar, Electrical Characterization and Reliability Analysis of HfO2-TiO2-Al MOSCAPs, WASET, 3: p. 92-94 (2009).
64
[63] Y. Zang and R. Farnood, Photocatalytic decomposition of methyl tert-butyl ether in aqueous slurry of titanium dioxide, Appl. Catal. B Environ., 57: p. 275-282 (2005).
[64] I. K. Konstantinou and T. A. Albanis, TiO2-assisted photocatalytic degradation of azo dyes in aqueous solution: kinetic and mechanistic investigations A review, Appl. Catal. B Environ., 49: p. 1-14 (2004).
[65] J. Zhao and H. Hidaka, Photodegradation of Surfactants. 11.Ϛ-Potential Measurements in the Photocatalytic Oxidation of Surfactants in Aqueous TiO2 Dispersions, Langmuir, 9: p. 1646-1650 (1993).
[66] M. Salehi, H. Hashemipour and M. Mirzaee, Experimental Study of Influencing Factors and Kinetics in Catalytic Removal of Methylene Blue with TiO2 Nanopowder, Am. J. Environ. Eng., 2: p. 1-7 (2012).
[67] I.-W. Huang, C.-S. Hont and B. Bush, Photocatalytic Degradation Of PCBs In TiO2 Aqueous Suspensions, chemosphere, 32: p. 1869-1881 (1996).
[68] F. Zhang, J. Zhaoa, T. Shen, H. Hidaka, E. Pelizzetti and N. Serpone, TiO2-assisted photodegradation of dye pollutants II. Adsorption and degradation kinetics of eosin in TiO2 dispersions under visible light irradiation, Appl. Catal. B Environ., 15: p. 147-156 (1998).
[69] T. N. Obee and S. T. Hay, Effects of Moisture and Temperature on the Photooxidation of Ethylene on Titania, Environ. Sci. Technol. 31: p. 2034-2038 (1997).
[70] D. Chen and A. K. Ray, Photodegradation Kinetics Of 4-Nitrophenol In TiO2 Suspension, Wat. Res., 32: p. 3223-3234 (1998).
[71] L. Meng, T. Ren and C. Li, The control of the diameter of the nanorods prepared by dc reactive magnetron sputtering and the applications for DSSC,
65
Applied Surface Science, 256: p. 3676–3682 (2010).
[72] X. Zhang, J. Qin, Y. Xue, P. Yu, B. Zhang, L. Wang and R. Liu, Effect of aspect ratio and surface defects on the photocatalytic activity of ZnO nanorods, Sci. Rep., 4: p. 1-8 (2014).
[73] S.-Z. Kang, Z. Xu, Y. Song and J. Mu, Photocatalytic Activity of High Aspect Ratio TiO2 Nanorods, J. Dispersion Sci. Technol., 27: p. 857-859 (2006).
[74] S. M. Bhola and B. Mishra, Effect of pH on the Electrochemical Properties of Oxides formed over β – Ti-15Mo and Mixed Ti-6Al-4V Alloys, Int. J. Electrochem. Sci., 8: p. 7075-7087 (2013).
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