本實驗採用簡易、低成本且迅速的過電位定電壓沉積法(Over potential chronoamperometry deposition)施加負於能斯特電位之電壓，沉積氧化鋅於氧化銦錫(Indium Tin Oxide, ITO)玻璃基材表面，並將其作為光觸媒應用於紫外光催化羅丹明6G(Rhodamine 6G)染料，接續透過光還原法(Photoreduction)還原金屬銀於氧化鋅表面進行修飾用以改質氧化鋅，探討可見光下催化作用。
使用三電極系統將石英槽置於矽油浴鍋中進行電沉積，本研究探討硝酸鋅前驅液濃度、製備pH值、製備電壓、製備溫度對電沉積氧化鋅薄膜之影響，修飾銀則探討光還原時間之影響。分別使用電化學儀(Electrochemical analyzer)以循環伏安法測定沉積電位以及電沉積、掃描式電子顯微鏡(SEM)進行表面形貌分析、X射線繞射儀分析儀(XRD)進行晶體結構確認與分析、能量分散式光譜分析儀(EDS)分析元素組成。採用8 W 254 nm紫外光燈管將氧化鋅薄膜應用於紫外光催化降解羅丹明6G染料、修飾銀之氧化鋅薄膜則置採用6 W可見光燈泡進行可見光催化降解羅丹明6G染料，並以光纖可見光光譜儀(VIS-Spectrometer)檢測吸收值並換算降解率。
實驗結果可得知150 mM之硝酸鋅溶液不調整pH值，電沉積過程中施加-1.4 V電壓在80°C環境下沉積10分鐘之氧化鋅薄膜，表面形貌為碎片狀團簇、晶體結構為氧化鋅纖鋅礦，具有最佳紫外光催化羅丹明6G效能。利用光還原法15分鐘修飾銀為最適條件，修飾銀之氧化鋅薄膜經由表面形貌、晶體結構、元素組成分析進行分析，並於可見光範圍光催化降解R6G。

In this work, zinc oxide thin film was electrodeposited on ITO glass (Indium tin oxide glass) substrate in the presence of zinc nitrate hexahydrate by chronoamperometry. To optimize deposition parameters, we explored the concentration of zinc nitrate hexahydrate, the pH values, deposition potentials, and deposition temperatures. The zinc oxide thin film was characterized by scanning electron microscopy (SEM), X-ray diffractometer (XRD), energy-dispersive X-ray spectroscopy (EDS), and fiber visible spectrometer. Zinc oxide thin film was used for photocatalysis Rhodamine 6G (R6G) via irradiating by 8 W 254 nm ultraviolet lamp. We measured the absorption of R6G solution, and transfer to concentration via using Beer-Lambert Law for photocatalytic efficiency. In order to catalyze R6G under visible light, we also applied method which was photoreduction to deposition silver on zinc oxide thin film for modifying the material. This experiment was low cost, environmentally friendly, and also easy to make for catalyzing R6G.

[1] Z. Hasan and S. H. Jhung, ": Removal of hazardous organics from water using metal-organic frameworks (MOFs) plausible mechanisms for selective adsorptions," Journal of Hazardous Materials, vol. 283, pp. 329-339, 2015.
[2] J.-W. Lee, S.-P. Choi, R. Thiruvenkatachari, W.-G. Shim, and H. Moon, "Evaluation of the performance of adsorption and coagulation processes for the maximum removal of reactive dyes," Dyes and Pigments, vol. 69, pp. 196-203, 2006.
[3] V. Katheresan, J. Kansedo, and S. Y. Lau, "Efficiency of various recent wastewater dye removal methods: a review," Journal of Environmental Chemical Engineering, vol. 6 pp. 4676-4697, 2018.
[4] A. Fujishima, and K. Honda, "Electrochemical photolysis of water at a semiconductor electrode," Nature, vol. 238, pp. 37-38, 1972.
[5] R. W. Matthews, "Kinetics of photocatalytic oxidation of organic solutes over titanium dioxide," Journal of Catalysis, vol. 111, pp. 264-272, 1988.
[6] J. J. Rueda-Marquez, I. Levchuk, P. Fernández Ibañez, and M. Sillanpää, "A critical review on application of photocatalysis for toxicity reduction of real wastewaters," Journal of Cleaner Production, vol. 258, p. 120694, 2020.
[7] M. Honarmand, M. Golmohammadi, and A. Naeimi, "Green synthesis of SnO2-bentonite nanocomposites for the efficient photodegradation of methylene blue and eriochrome black-T," Materials Chemistry and Physics, vol. 241, p. 122416, 2020.
[8] M. Grätzel, "Photoelectrochemical cells," Nature, vol. 414, pp. 338-344, 2001.
[9] A. Y. Skoblov, M. V. Vichuzhanin, V. M. Farzan, O. A. Veselova, T. A. Konovalova, A. T. Podkolzin, G. A. Shipulin, and T. S. Zatsepin, "Solid- and solution-phase synthesis and application of R6G dual-labeled oligonucleotide probes," Bioorganic & Medicinal Chemistry, vol. 23, pp. 6749-6756, 2015.
[10] M. V. Rigo, J. Seo, W.-J. Kim, and S. Jung, "Plasmon coupling of R6G-linked gold nanoparticle assemblies for surface-enhanced raman spectroscopy," Vibrational Spectroscopy, vol. 57, pp. 315-318, 2011.
[11] L. Jensen and G. C. Schatz, "Resonance raman scattering of rhodamine 6G as calculated using time-dependent density functional theory," The Journal of Physical Chemistry A, vol. 110, pp. 5973-5977, 2006.
[12] R. F. Kubin and A. N. Fletcher, "Fluorescence quantum yields of some rhodamine dyes," Journal of Luminescence, vol. 27, pp. 455-462, 1982.
[13] L. Yang, J. Hu, L. He, J. Tang, Y. Zhou, J. Li, and K. Ding, "One-pot synthesis of multifunctional magnetic N-doped graphene composite for SERS detection, adsorption separation and photocatalytic degradation of Rhodamine 6G," Chemical Engineering Journal, vol. 327, pp. 694-704, 2017.
[14] W. Xiaohong, J. Zhaohua, L. Huiling, L. Xuandong, and H. Xinguo, "TiO2 ceramic films prepared by micro-plasma oxidation method for photodegradation of rhodamine B," Materials Chemistry and Physics, vol. 80, pp. 39-43, 2003.
[15] D. Lutic, C. Coromelci-Pastravanu, I. Cretescu, I. Poulios, and C.-D. Stan, "Photocatalytic treatment of rhodamine 6G in wastewater using photoactive ZnO," International Journal of Photoenergy, vol. 2012, p. 475131, 2012.
[16] T. J. Coutts, D. L. Young, and X. Li, "Characterization of transparent conducting oxides," MRS Bulletin, Cambridage University Press, Cambridage, United Kingdom, vol. 25, pp. 58-65, 2000.
[17] M. A. Aouaj, R. Diaz, A. Belayachi, F. Rueda, and M. Abd-Lefdil, "Comparative study of ITO and FTO thin films grown by spray pyrolysis," Materials Research Bulletin, vol. 44, pp. 1458-1461, 2009.
[18] H. A. Abdulgader, V. Kochkodan, and N. Hilal, "Hybrid ion exchange – pressure driven membrane processes in water treatment: a review," Separation and Purification Technology, vol. 116, pp. 253-264, 2013.
[19] H. Abu Hasan, M. H. Muhammad, and N. I. Ismail, "A review of biological drinking water treatment technologies for contaminants removal from polluted water resources," Journal of Water Process Engineering, vol. 33, p. 101035, 2020.
[20] S. Majumder, P. Basnet, J. Mukherjee, and S. Chatterjee, "Bio-capped facile synthesis of silver zinc oxide for photocatalytic degradation of rhodamine 6G under visible-light irradiation," AIP Conference Proceedings, vol. 2265, p. 030093, 2020.
[21] C. Klingshirn, "ZnO: Material, Physics and Applications," ChemPhysChem, vol. 8, pp. 782-803, 2007.
[22] 曾心如, "以水熱法在異質基板上成長氧化鋅之研究," 國立交通大學, 碩士論文 新竹市, 2013.
[23] B. Meyer and D. Marx, "Density-functional study of the structure and stability of ZnO surfaces," Physical Review B, vol. 67, p. 035403, 2003.
[24] N. Selvakumar and H. C. Barshilia, "Review of physical vapor deposited (PVD) spectrally selective coatings for mid- and high-temperature solar thermal applications," Solar Energy Materials and Solar Cells, vol. 98, pp. 1-23, 2012.
[25] T. Noyhouzer and D. Mandler, "Determination of low levels of cadmium ions by the under potential deposition on a self-assembled monolayer on gold electrode," Analytica Chimica Acta, vol. 684, pp. 1-7, 2011.
[26] P. T. Kissinger and W. R. Heineman, "Cyclic voltammetry," Journal of Chemical Education, vol. 60, p. 702, 1983.
[27] M. S. Chandrasekar and M. Pushpavanam, "Pulse and pulse reverse plating—Conceptual, advantages and applications," Electrochimica Acta, vol. 53, pp. 3313-3322, 2008.
[28] E. Matei, M. Enculescu, N. Preda, and I. Enculescu, "ZnO morphological, structural and optical properties control by electrodeposition potential sweep rate," Materials Chemistry and Physics, vol. 134, pp. 988-993, 2012.
[29] F. Xu, Y. Lu, L. Xia, Y. Xie, M. Dai, and Y. Liu, "Seed layer-free electrodeposition of well-aligned ZnO submicron rod arrays via a simple aqueous electrolyte," Materials Research Bulletin, vol. 44, pp. 1700-1708, 2009.
[30] A. H. Ismail, A. H. Abdullah, and Y. Sulaiman, "Physical and electrochemical properties of ZnO films fabricated from highly cathodic electrodeposition potentials," Superlattices and Microstructures, vol. 103, pp. 171-179, 2017.
[31] N. Roy and S. Chakraborty, "ZnO as photocatalyst: an approach to waste water treatment," Materials Today: Proceedings, vol. 46, pp. 6399-6403, 2020.
[32] L. Kaliraj, J. C. Ahn, E. J. Rupa, S. Abid, J. Lu, and D. C. Yang, "Synthesis of panos extract mediated ZnO nano-flowers as photocatalyst for industrial dye degradation by UV illumination," Journal of Photochemistry and Photobiology B: Biology, vol. 199, p. 111588, 2019.
[33] S. Rajoriya, S. Bargole, and V. K. Saharan, "Degradation of a cationic dye (rhodamine 6G) using hydrodynamic cavitation coupled with other oxidative agents: reaction mechanism and pathway," Ultrasonics Sonochemistry, vol. 34, pp. 183-194, 2017.
[34] Y. Cao, X. Zhang, W. Yang, H. Du, Y. Bai, T. Li, and J. Yao., "A bicomponent TiO2/SnO2 particulate film for photocatalysis," Chemistry of Materials, vol. 12, pp. 3445-3448, 2000.
[35] S. Ekambaram, Y. Iikubo, and A. Kudo, "Combustion synthesis and photocatalytic properties of transition metal-incorporated ZnO," Journal of Alloys and Compounds, vol. 433, pp. 237-240, 2007.
[36] J. Xu, Y. Chang, Y. Zhang, S. Ma, Y. Qu, and C. Xu, "Effect of silver ions on the structure of ZnO and photocatalytic performance of Ag/ZnO composites," Applied Surface Science, vol. 255, pp. 1996-1999, 2008.
[37] J. J. Wu and C. H. Tseng, "Photocatalytic properties of nc-Au/ZnO nanorod composites," Applied Catalysis B: Environmental, vol. 66, pp. 51-57, 2006.
[38] H. Han, N. D. Theodore, and T. L. Alford, "Improved conductivity and mechanism of carrier transport in zinc oxide with embedded silver layer," Journal of Applied Physics, vol. 103, p. 013708, 2008.
[39] A. Sytchkova, M. L. Grilli, A. Rinaldi, S. Vedraine, P. Torchio, A. Piegari, and F. Flory, "Radio frequency sputtered Al:ZnO-Ag transparent conductor: a plasmonic nanostructure with enhanced optical and electrical properties," Journal of Applied Physics, vol. 114, p. 094509, 2013.
[40] K. Sivaramakrishnan, and T. L. Alford, "Metallic conductivity and the role of copper in ZnO/Cu/ZnO thin films for flexible electronics," Applied Physics Letters, vol. 94, p. 052104, 2009.
[41] H. Yang, S. Shin, J. Park, G. Ham, J. Oh, and H. Jeon, "Effect of Au interlayer thickness on the structural, electrical, and optical properties of GZO/Au/GZO multilayers," Current Applied Physics, vol. 14, pp. 1331-1334, 2014.
[42] W. Yang, Z. Wu, Z. Liu, and L. Kong, "Deposition of Ni, Ag, and Pt-based Al-doped ZnO double films for the transparent conductive electrodes by RF magnetron sputtering," Applied Surface Science, vol. 256, pp. 7591-7595, 2010.
[43] C. Lee, R. P. Dwivedi, W. Lee, C. Hong, W. I. Lee, and H. W. Kim, "IZO/Al/GZO multilayer films to replace ITO films," Journal of Materials Science: Materials in Electronics, vol. 19, pp. 981-985, 2008.
[44] C. Ren, B. Yang, M. Wu, J. Xu, Z. Fu, Y. Lv, T. Guo, Y. Zhao, and C.Zhu, "Synthesis of Ag/ZnO nanorods array with enhanced photocatalytic performance," Journal of Hazardous Materials, vol. 182, pp. 123-129, 2010.
[45] K. Kawano, M. Komatsu, Y. Yajima, H. Haneda, H. Maki, and T. Yamamoto, "Photoreduction of Ag ion on ZnO single crystal," Applied Surface Science, vol. 189, pp. 265-270, 2002.
[46] H. Liu, Y. Hu, Z. Zhang, X. Liu, H. Jia, and B. Xu, "Synthesis of spherical Ag/ZnO heterostructural composites with excellent photocatalytic activity under visible light and UV irradiation," Applied Surface Science, vol. 355, pp. 644-652, 2015.
[47] S. A. Ansari, M. M. Khan, M. O. Ansari, J. Lee, and M. H. Cho, "Biogenic synthesis, photocatalytic, and photoelectrochemical performance of Ag–ZnO nanocomposite," The Journal of Physical Chemistry C, vol. 117, pp. 27023-27030, 2013.
[48] C. Yang, and Q. Li, "ZnO inverse opals with deposited Ag nanoparticles: fabrication, characterization and photocatalytic activity under visible light irradiation," Journal of Photochemistry and Photobiology A: Chemistry, vol. 371, pp. 118-127, 2019.
[49] Y. Liu, S. Wei, and W. Gao, "Ag/ZnO heterostructures and their photocatalytic activity under visible light: effect of reducing medium," Journal of Hazardous Materials, vol. 287, pp. 59-68, 2015.
[50] S. Allahveran, and A. Mehrizad, "Polyaniline/ZnS nanocomposite as a novel photocatalyst for removal of rhodamine 6G from aqueous media: optimization of influential parameters by response surface methodology and kinetic modeling," Journal of Molecular Liquids, vol. 225, pp. 339-346, 2017.
[51] B. J. Inkson, "2 - Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for materials characterization," Materials Characterization Using Nondestructive Evaluation (NDE) Methods, Woodhead Publishing, Sawston, United Kingdom, pp. 17-43, 2016
[52] C. O. Colpan, Y. Nalbant, and M. Ercelik, "4.28 Fundamentals of fuel cell technologies," Comprehensive Energy Systems, I. Dincer, Ed. Oxford: Elsevier, Amsterdam, Netherlands, pp. 1107-1130, 2018
[53] M. Birkholz, P. F. Fewster, and C. Genzel, "Thin film analysis by X-ray scattering." Journal od applied crystallography, vol. 39, pp. 925-926, 2006.
[54] J. Yang, Y. Wang, J. Kong, H. Jia, and Z. Wang, "Synthesis of ZnO nanosheets via electrodeposition method and their optical properties, growth mechanism," Optical Materials, vol. 46, pp. 179-185, 2015.
[55] A. G. Ardakani and P. Rafieipour, "Using ZnO nanosheets grown by electrodeposition in random lasers as scattering centers: the effects of sheet size and presence of mode competition," Journal of the Optical Society of America B: Optical Physics, vol. 35, pp. 1708-1716, 2018.
[56] B. Bayarri, M. N. Abellán, J. Giménez, and S. Esplugas, "Study of the wavelength effect in the photolysis and heterogeneous photocatalysis," Catalysis Today, vol. 129, pp. 231-239, 2007.
[57] C.-C. Lin and L.-J. Hsu, "Removal of polyvinyl alcohol from aqueous solutions using P-25 TiO2 and ZnO photocataysts: a comparative study," Powder Technology, vol. 246, pp. 351-355, 2013.
[58] M. Guo, C. Yang, M. Zhang, Y. Zhang, T. Ma, X. Wang, and X. Wang, "Effects of preparing conditions on the electrodeposition of well-aligned ZnO nanorod arrays," Electrochimica Acta, vol. 53, pp. 4633-4641, 2008.
[59] A. Goux, T. Pauporté, J. Chivot, and D. Lincot, "Temperature effects on ZnO electrodeposition," Electrochimica Acta, vol. 50, pp. 2239-2248, 2005..
[60] H. Chun, W. Yizhong, and T. Hongxiao, "Destruction of phenol aqueous solution by photocatalysis or direct photolysis," Chemosphere, vol. 41, pp. 1205-1209, 2000.
[61] B. Neppolian, H. C. Choi, S. Sakthivel, B. Arabindoo, and V. Murugesan, "Solar/UV-induced photocatalytic degradation of three commercial textile dyes," Journal of Hazardous Materials, vol. 89, pp. 303-317, 2002.
[62] R. A. Damodar, K. Jagannathan, and T. Swaminathan, "Decolourization of reactive dyes by thin film immobilized surface photoreactor using solar irradiation," Solar Energy, vol. 81, pp. 1-7, 2007.
[63] F. Hashemzadeh, R. Rahimi, and A. Gaffarinejad, "Photocatalytic degradation of methylene blue and rhodamine B dyes by niobium oxide nanoparticles synthesized via hydrothermal method," International Journal of Applied Chemical Sciences Research, vol. 1, pp.95-102, 2013.
[64] C. Zhang, J. Zhang, Y. Su, M. Xu, Z. Yang, and Y. Zhang, "ZnO nanowire/reduced graphene oxide nanocomposites for significantly enhanced photocatalytic degradation of rhodamine 6G," Physica E: Low-dimensional Systems and Nanostructures, vol. 56, pp. 251-255, 2014.
[65] S.-L. Lin, K.-C. Hsu, C.-H. Hsu, and D.-H. Chen, "Hydrogen treatment-improved uniform deposition of Ag nanoparticles on ZnO nanorod arrays and their visible-light photocatalytic and surface-enhanced raman scattering properties," Nanoscale Research Letters, vol. 8, p. 325, 2013.
[66] R. M. Kakhki, R. Tayebee, and F. Ahsani, "New and highly efficient Ag doped ZnO visible nano photocatalyst for removing of methylene blue," Journal of Materials Science: Materials in Electronics, vol. 28, pp. 5941-5952, 2017.
[67] M. H. Wang, H. L. Cai, Z. L. Guo, Q. A. Qiao, S. H. Ren, D. D. Zhu, Z. X. Xue, "Synthesis of hexagonal-like ZnO/Ag composite with excellent photocatalytic activity," Micro & Nano Letters, vol. 14, pp. 656-660, 2019.