- Email: [email protected]
TiO2 nanoparticles electrode-based on electrochemiluminescence (ECL) cell application
Fabrication of Carbon Nanotubes/TiO2 Nanoparticles Electrode-Based on Electrochemiluminescence (ECL) Cell Application Pakpoom Chansri, Youl-Moon Sung PII: DOI: Reference:
S0257-8972(16)30590-4 doi: 10.1016/j.surfcoat.2016.07.011 SCT 21341
To appear in:
Surface & Coatings Technology
Received date: Revised date: Accepted date:
24 December 2015 1 July 2016 4 July 2016
Please cite this article as: Pakpoom Chansri, Youl-Moon Sung, Fabrication of Carbon Nanotubes/TiO2 Nanoparticles Electrode-Based on Electrochemiluminescence (ECL) Cell Application, Surface & Coatings Technology (2016), doi: 10.1016/j.surfcoat.2016.07.011
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Fabrication of Carbon Nanotubes/TiO2 Nanoparticles Electrode-Based on Electrochemiluminescence (ECL) Cell Application
Department of Electrical Engineering, Kyungsung University, Busan, 608-736, Korea
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a
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Pakpoom Chansria and Youl-Moon Sunga,*
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* Corresponding author: Email: [email protected]; Tel.: +82 (0)516334777; Fax: +82
NU
(0)516245980; Plasma and Photoelectric Fusion Laboratory, Department of Electrical
MA
Engineering, College of Engineering, Kyungsung University, Busan, 608-736, Korea
Abstract
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In this paper, we fabricate an electrochemical luminescence (ECL) cell with carbon nanotubes/TiO2 nanoparticles (CNT-TNP) layer and coated on F-doped SnO2 (FTO) glass can be
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increased the surface area interface with the Ru(II) complex [Ru(bpy)3Cl2]. The investigated ECL cells were composed of FTO glass/ Ru(II)/ CNT-TNP electrode/ FTO glass, which compared TNP and bare FTO electrode. The luminance property of the ECL cell with CNT-TNP electrode was 59 cd/m2 more than bare FTO electrode up to 61%. Also, the threshold voltage of the light emission from ECL cell was 2.25 V for CNT-TNP electrode, which was lower than that 2.5 V for TNP, and 3.0 V for bare FTO electrode. The high efficiency of the ECL cell with CNTTNP measured at 4 V was 0.13615 lm/W and 0.13137 lm/W, while bare FTO electrode measured at 4.75 V was 0.10213 lm/W. The peak light intensity at wavelength was 622 nm which corresponds to a red-orange colour. The use of the CNT-TNP electrode layer coated on FTO glass significantly improves the light intensity performance.
ACCEPTED MANUSCRIPT Keywords: Carbon nanotubes/TiO2 nanoparticles; TiO2 nanoparticles; Ru(II) complex;
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electrochemical luminescence (ECL) cell.
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Abstract code: AP5
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1. Introduction
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Among various light-emitting technologies, electrochemi-luminescence (ECL) has been developed high luminescence efficiency, simplified optical configuration, and cost-effectiveness
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for manufacturing [1,2]. The ECL cell is an emission phenomenon’s electrochemical by injecting electrons into between electron and light emitting material. The ECL cell devices are a simple
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structure which consists of the two conductive electrodes and the light-emitting layer, which injected in the between two electrodes. The conductive electrodes use transparent conductive
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oxide (TCO) glass and the light-emitting layer use Ru(II) complex, it was widely used due to the strong light intensity and use low applied voltage [3,4]. Furthermore, in the addition of the oxide material electrodes deposited on TCO glass which can improve the light emission performance of the ECL cell device. Takase et al, [5] used TiO2 nanoparticle (TNP) grown on TCO glass was confirmed the high emission efficiency of the ECL cell with TNP (rutile and anatase). Moon et al, [6] presented nanostructure TiO2/Ti film deposited on TCO glass was found high luminance efficiency of the ECL cell with TiO2/Ti film. However, the TNP-coated TCO glass has still leakage and long-term stability problems [7]. The application of the most carbon nanotube (CNT) electrodes was widely used for electrogenerated chemiluminescence sensor due to it is a semiconductor and high electrical conductivity [8-11]. The CNT is formed from carbon atoms arranged in the sheet, which has a
ACCEPTED MANUSCRIPT high fluidity. CNT is similar to the structure of graphite. The CNT is coherence into a lattice with hexagonal holes, which is a pipe or a tube [12]. CNT is very small tubes about nanometer
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scale, which has a diameter of tubes in the range of 0.4 to 4.0 nm and band gaps 0.5 eV. It can
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be synthesized by two types; a single wall carbon nanotube (SWCNT) and a multi-wall carbon
SC
nanotube (MWCNT) [13]. Thus, we are focusing on ECL cell device with CNT-TNP composite in the type of SWCNT which may be increased the oxidation and reduction reaction of Ru(II)
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complex and recombination between Ru(I) and Ru(III), thus the overall conversion efficiency can increase.
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In this work, we report an ECL cells synthesized using CNT-TNP nanocomposite electrode. The CNT-TNP electrode coated on TCO glass can be increased the surface area interface with
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the Ru(II) complex. The structure of ECL cell with CNT-TNP consists of TCO glass/ CNT-TNP electrode/ Ru(II) complex/ TCO glass. The CNT-TNP synthesis has been mixed CNT and TNP
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in 10:90 of ratio. The applied CNT-TNP electrode can improve luminance efficiency and long lifetime of the ECL cell.
2. Experiment Methods
Fig. 1 shows schematic of the ECL cell with the CNT-TNP electrode layer which distance between the two TCO glass layers of the cell was 60 m. FTO glass was used TCO glass because of its excellent conductive that prevents further problems. The production method is described below. The electrode layer was coated with CNT-TNP 30 m thickness by using thermos-plastic sealing films, on one side of the FTO glass in the ECL cell. The Ru(II) complex was injected into the surface between the CNT-TNP electrode layer and the FTO glass.
ACCEPTED MANUSCRIPT The synthesis of CNT can be discussed in previous reports [14]. The CNTs solution was fabricated CNTs (muti-wall nanotube: MWNT; Hanwha Naonotech) powder and sodium
PT
dodecylbenzene sulfonate (SDBS; CHEMMAX) by mixing in the ratio 20 mg : 20 mg, and the
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deionized water of 20 ml for surfactant, stirred 10 minutes. The dispersion of CNTs was prepared by bath sonicator (Branson, 2510) for 5 min and bar sonicator (Sonics & material,
SC
VCX500) for 20 min [15,16].
NU
The TNP was prepared as a form of a paste using the anatase TiO2 powder. First, add 2.5 g of TiO2 into a mixture of 10 mL of α-Terpineol (KENTO Chemical) and 50 mL of ethanol 99.9 %.
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And mix them thoroughly with an ultrasonic cleaner. Then, add ethyl cellulose of 1.5 g little by little by using a binder and applying 40 C heats for 1 h, one can disperse ethyl cellulose in the
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solution. So, one makes all reagents diluted in the solution. After an evaporator is used, the TNP solution and CNT solution mixed in ratio 90:10 wt% for tested. The CNT-TNP solution coated
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on FTO glass at size 11 cm2 by doctor blade method and heat treatment at 450C in 30 min. The ECL cell was fabricated Ru(bpy)3Cl2 (SIGMA-Aldrich) and NH4PF6 (WAKO) and propylene carbonate (PC; SIGMA-Aldrich). Ru(bpy)3(FP6)2 to synthesized via mixing Ru(bpy)3Cl2 and NH4PF6 (0.5 g : 0.5 g) in aqueous solution, stirring process to the solution for 1 h, and was dried under vacuum for 24 h. The Ru(bpy)3(FP6)2 powder and PC solution ratio was achieved at 0.04 g : 0.448 g. The fabricated ECL cell in this experiment was attached to the sealing machine (area of 11 cm2), and Ru(bpy)3 (FP6)2 was injected between FTO glasses, to finish the process.
ACCEPTED MANUSCRIPT 3. Results and discussion We prepared the ECL cell with the CNT-TNP electrode layer. The structural properties of
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CNT-TNP electrode were measured field emission scanning electron microscope (FE-SEM;
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Hitachi S-3000H). Figure 2 shows Top view and cross-sectional view SEM image of the CNTTNP films on the FTO glass. Figure 2(a) shows the CNT-TNP with cross-sectional view SEM
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image. In order to obtain a thickness of the CNT-TNP films was controlled to 30 µm following
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optimum conditions. The TNPs were a mix on the CNTs. The high magnification image of the CNT-TNP films showed the aggregation and adhesion of the TNP into CNT, as it seen in Fig.
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2(a) inset. Figure 2(b) shows top view surface of the CNT-TNP, was very rough and rounded on the surface.
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The luminance properties of ECL cell with CNT-TNT electrode layer measured by the spectral brightness analyzer (Konica Minota, CS-200A). The ECL cell represents electrode
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material, thus sample CNT-TNP electrodes have the following configurations: FTO Glass/ Ru(II)/ CNT-TNP (10µm)/ FTO Glass, FTO Glass/ Ru(II)/ TNPs (10µm)/ FTO Glass and FTO Glass/ Ru(II)/ FTO Glass, respectively. The light emission spectra of the ECL cells with TNP, CNT-TNP, and bare FTO are shown in Fig. 3. The peak intensity was 622 nm of the wavelengths which was not influenced to all electrodes by the operation condition of ECL devices at 4 V AC, 60 Hz. All electrodes of the ECL cells were showed responds dark orange emission of the ECL cell and confirmed not to influence ECL device’s luminous color. The luminance of the ECL cell with CNT-TNP, TNPs, and bare FTO are shown in Fig 4. When the applied AC voltage on the cell is 0 to 5.0 V peak and 60 Hz. The threshold voltage of the initial light emission was 2.25 V for CNT-TNP less than 2.5 V for TNP and 3.0 V for bare FTO electrodes. The intensity of the ECL cell was 59 cd/m2 for CNT-TNP, 50.8 cd/m2 for TNP,
ACCEPTED MANUSCRIPT and 23 cd/m2 for bare FTO electrodes. The best of the threshold voltage of the initial light emission and intensity were CNT-TNP films, due to the mean free path of the positive charge
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and a negative charge radicals in the CNT-TNP electrode causing the electrons fast transfer to
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Ru(bpy)32+ increase. Thus, the efficient current injection from CNT-TNP (the low threshold voltage) and the large contact area on the surface of the TNP.
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For, the electrical properties of the ECL cells with CNT-TNP film were measured by the
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sheet resistance meter (Dasol Eng, FPP-H8), a digital function generator (Agilent 33250A) and digital storage oscilloscope (Tektronix DPO 3034). The sheet resistance (Ω/sq) of the TNP and
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CNT-TNP films was measured on the surface area of TNP, CNT-TNP, and bare FTO (11 cm2 of the area). The sheet resistance of the TNPs was 7.79 Ω/sq, 7.63 Ω/sq for CNT-TNP, and 8.89
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Ω/sq for bare FTO. The sheet resistance of CNT-TNP was less than that TNP and bare FTO due
electron.
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to CNT-TNP was high porosity in the three dimensions interfaces with a large amount of
The current and voltage (I-V curve) of the ECL cells used by CNT-TNP, TNP, and bare FTO electrode are shown in Fig. 5. The output current of the ECL cell with CNT-TNP electrode was 65.24 mA, 58.13 mA for TNP and 40.21 mA for bare FTO electrodes, at 4.0 V. The best of the current was CNT-TNP due to the sheet resistance of the CNT-TNP less than TNP electrode. The power efficiency of the ECL cell can be known performances light intensity per electrical power (lm/W) [17-19]. Figure 6 is shown ECL efficiencies of the ECL cell with CNTTNP, TNP, and bare FTO electrode. The ECL efficiency of the ECL cell with CNT-TNP was 0.13615 lm/W more than 0.13137 lm/W for TNP at 4.0 V and 0.10213 lm/W for bare FTO electrode at 4.75 V. The highest ECL efficiency of the ECL cell with CNT-TNP electrode can be explained by increase the amount of the electrons on large surface of the CNT-TNP electrode
ACCEPTED MANUSCRIPT layer. The ECL efficiency of the used CNT-TNP, TNP, and bare FTO electrode were decreased because of the voltage increases, causing the high-density electrons flow through the region in
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large numbers on the surface of the electrodes and Ru(II). The optimum applied a voltage of
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ECL cells was 4.0 V.
3. Conclusion
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The effect of the electrical and optical characteristics of the ECL cell is using CNT-TNP electrode. The CNT-TNP electrode was compared a TNP and bare electrode. All characteristics
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of the ECL cells with each electrode can show the following: 1. At the voltage 4.0 V 60 Hz, the luminance properties of the ECL cell with CNT-TNP
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electrode was 59 cd/m2 which more than 50.8 cd/m2 for TNP and 23 cd/m2 for bare FTO electrode. The highest peak intensity of the ECL cell was CNT-TNP at wavelength 622 nm and
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show response dark-orange color.
2. At 4.0 V, the electrical properties (I-V curve) of the ECL cell with CNT-TNP, TNP and bare FTO electrode was 65.24 mA, 58.13mA and 40.21 mA, respectively. The ECL cell with CNT-TNP electrode was higher than all electrodes. 3. The ECL efficiency of the ECL cell with CNT-TNP was 0.13615 lm/W more than that TNP and bare FTO electrode. Considering, the optimum all properties of the each electrode are CNT-TNP electrode. Applying the CNT-TNP film electrode layer on the ECL cell increased the interface area of the electrode, it may increase transfer oxidation/reduction reaction of the Ru(II) complex, which results in significant increase of ECL cell efficiency.
ACCEPTED MANUSCRIPT Acknowledgements This research (Grants No.C0193902) was supported by Business for Academic-industrial
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Cooperative establishments funded by Korea Small and Medium Business Administration in
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2015.
ACCEPTED MANUSCRIPT References [1] M. M. Richter, Electrochemiluminescence (ECL), Chem. Rev. 104 (2004) 3003-3036.
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[2] A. J. Bard and L. R. Faulkner: Electrochemical Methods Fundamentals and Applications
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(Wiley, New York, 2001) P.15.
[3] H.Rudmann, S. Shinada and M. F. Rubner, Solid-state light-emitting devices based on the
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tris-chelated ruthenium(II) complex. 4. High-efficiency light-emitting devices based on
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derivatives of the tris(2,2 '-bipyridyl) ruthenium(II) complex, J. Am. Chem. Soc. 124 (2002) 4918 – 4921.
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[4] T. Kado, M. Takenouchi, S. Okamoto, W. Takashima, K. Kaketo, and A. Hayase, Enhanced Electrochemi luminescence by Use of Nanoporous TiO2 Electrodes: Electrochemiluminescence
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Devices Operated with Alternating Current, Jpn. J Appl. phys. 44 (2005) 8161-8164. [5] M. Takase, S. Sugimoto, K. Nakamura, and N. Kobayashi, Effect of TiO2 Nanoparticle on
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Electrochemi luminescent Properties in Ru(bpy)3-based Emissive Display, Display. Imaging. 1 (2013) 97-104.
[6] B. H. Moon, D. J Kwak, Y. M Sung, “Optical and Electrochemical Characteristics of Nanostructural TiO2/Ti/ Glass Electrode,” Inter. J. Theo. Appl. Nanotech., vol.1, issue 1, pp.8669, 2012.
[7] H.M. Kwon, C.H. Han, Y.M. Sung, Fabrication of High Efficiency Electrochemiluminescence Cell with Nanocrystalline TiO2 Electrode, Trans KIEE 59 (2010) 363–368. [8] H. N. Choi, J. Y. Lee, Y. K. Lyu, W. Y. Lee, Tris(2,2-bipyridyl)ruthenium(II) electrogenerated chemiluminescence sensor based on carbon nantube dispersed in sol–gelderived titania–Nafion composite films, Analytica Chimica Acta 565 (2006) 48–55.
ACCEPTED MANUSCRIPT [9] L. Shen, J. Li, L. Li, G. Zou, X. Zhang, W. Jin, Ultrasensitive electrochemiluminescence method for determination of DNA using Ru(bpy)32+-coated magnetic submicrobeads wrapped
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with carbon nanotubes, Electrochem. Commun. 13 (2011) 1499-1501.
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[10] A. Venkatanarayanan, K. Crowley, E. Lestini, T. E. Keyes, J. F. Rusling, R. J. Forster, High sensitivity carbon nanotube based electrochemiluminescence sensor array, Biosensors.
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Bioelectron. 31 (2012) 233-239.
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[11] A. T. Lawal, Synthesis and utilization of carbon nanotubes for fabrication of electrochemical biosensors, Mater. Res. Bull. 73 (2016) 308-350.
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[12] Y. K. Kwon and D. Toma´nek, “Electronic and structural properties of multiwall carbon nanotubes,” Phys. Rev. B 58 (1998) R16001(R).
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[13] Y. Xu, J. Liu, C. Gao, E. Wang, Applications of carbon quantum dots in electrochemiluminescence: A mini review Electrochem. Commun. 48 (2014) 151-154.
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[14] E. Kymakis, M. M. Stylianakis, G. D. Spyropoulos, E. Stratakis, E. Koudoumas, and C. Fotakis, “Spin coated carbon nanotubes as the hole trans port layer inorganic photovoltaics,” Solar Energy Materials & Solar Cells, vol. 96, pp.298–301, 2012. [15]
Ray H. Baughman, Anvar A. Zakhidov, Walt A. de Heer, “Carbon nanotubes-the route
toward applications,” Science, vol.297, pp.787–792, 2002. [16] Yu Jin Kang, Haegeun Chung, Chi-Hwan Han, Woong Kim, “All-solid-state flexible supercapacitors based on papers coated with carbon nanotubes and ionic-liquid-based gel electrolytes,” Nanotechnology, vol. 23, no. 6, pp. 065401, 2012. [17] H. D. Park, Y. M. Sung, M. W. Park, J. E. Song, “Comparison
of electrochemical
luminescence Charecteristics of titanium dioxide films prepared by sputtering and sol-gel combustion methods,” Jpn. J Appl. phys. 52 (2013) 50EC04 1-4.
ACCEPTED MANUSCRIPT [18] P. Chansri, Y. M. Sumg, “Synthesis and characterization of TiO2 on ZnO-nanorod layer for high-efficiency electrochemiluminescence cell application”, Jpn. J Appl. phys. 55 (2016) 02BB1
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1-5.
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[19] P. Chansri, Y. M. Sumg, “Investigations of electrochemical luminescence characteristics of ZnO/TiO2 nanotubes electrode and silica-based gel type solvents”, Surface & Coatings
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Technology 294 (2016) 220–224.
ACCEPTED MANUSCRIPT Figure Captions Fig. 1 Schematic of ECL cell with CNT-TNP electrode.
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Fig. 2 SEM image of CNT-TNP film (a) cross-sectional view (b) top view.
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Fig. 3 Spectral brightness intensity of ECL cell with CNT-TNP, TNP and bare FTO.
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Fig. 4 Light intensity of ECL cell with CNT-TNP, TNP and bare FTO. Fig. 5 I-V curve of ECL cell with CNT-TNP, TNP and bare FTO.
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Fig. 6 ECL intensity of ECL cell with CNT-TNP, TNP and bare FTO.
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ACCEPTED MANUSCRIPT
60µm
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FTO glass Ru(bpy3)2+
Sealing
CNT-TNP 30µm
FTO glass
Fig. 1 Schematic of ECL cell with CNT-TNP electrode.
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ACCEPTED MANUSCRIPT
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(b) Fig. 2 SEM image of CNT-TNP film (a) cross-sectional view (b) top view.
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ECL Intensity [arb. unit]
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Fig. 3 Spectral brightness intensity of ECL cell with CNT-TNP, TNP and bare FTO.
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CNT-TNP TNP Bare FTO
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2 Intensity [cd/m ]
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Applied Voltage [V]
Fig. 4 Light intensity of ECL cell with CNT-TNP, TNP and bare FTO.
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Fig. 5 I-V curve of ECL cell with CNT-TNP, TNP and bare FTO.
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ECL Efficiency [lm/W]
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Fig. 6 ECL intensity of ECL cell with CNT-TNP, TNP and bare FTO.
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Highlights
The minimum threshold voltage at light emission start was 2.25 V for CNT-TNP electr ode.
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A simple preparation process for advanced ECL cell using carbon nanotube/TiO2 nanopartic le (CNT-TNP). The CNT-TNP was fabricated by mixture ratio TNP = 90 wt% : CNT = 10wt%
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The electrical and optical properties of the ECL cell with CNT-TNP electrode were 59 cd /m2 for light intensity, 65.24 mA for output current, and 0.13615 lm/W for ECL effici ency At 4 V 60 Hz (1×1 cm2 of area size).
S0257-8972(16)30590-4 doi: 10.1016/j.surfcoat.2016.07.011 SCT 21341
To appear in:
Surface & Coatings Technology
Received date: Revised date: Accepted date:
24 December 2015 1 July 2016 4 July 2016
Please cite this article as: Pakpoom Chansri, Youl-Moon Sung, Fabrication of Carbon Nanotubes/TiO2 Nanoparticles Electrode-Based on Electrochemiluminescence (ECL) Cell Application, Surface & Coatings Technology (2016), doi: 10.1016/j.surfcoat.2016.07.011
This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Fabrication of Carbon Nanotubes/TiO2 Nanoparticles Electrode-Based on Electrochemiluminescence (ECL) Cell Application
Department of Electrical Engineering, Kyungsung University, Busan, 608-736, Korea
RI
a
PT
Pakpoom Chansria and Youl-Moon Sunga,*
SC
* Corresponding author: Email: [email protected]; Tel.: +82 (0)516334777; Fax: +82
NU
(0)516245980; Plasma and Photoelectric Fusion Laboratory, Department of Electrical
MA
Engineering, College of Engineering, Kyungsung University, Busan, 608-736, Korea
Abstract
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D
In this paper, we fabricate an electrochemical luminescence (ECL) cell with carbon nanotubes/TiO2 nanoparticles (CNT-TNP) layer and coated on F-doped SnO2 (FTO) glass can be
AC CE P
increased the surface area interface with the Ru(II) complex [Ru(bpy)3Cl2]. The investigated ECL cells were composed of FTO glass/ Ru(II)/ CNT-TNP electrode/ FTO glass, which compared TNP and bare FTO electrode. The luminance property of the ECL cell with CNT-TNP electrode was 59 cd/m2 more than bare FTO electrode up to 61%. Also, the threshold voltage of the light emission from ECL cell was 2.25 V for CNT-TNP electrode, which was lower than that 2.5 V for TNP, and 3.0 V for bare FTO electrode. The high efficiency of the ECL cell with CNTTNP measured at 4 V was 0.13615 lm/W and 0.13137 lm/W, while bare FTO electrode measured at 4.75 V was 0.10213 lm/W. The peak light intensity at wavelength was 622 nm which corresponds to a red-orange colour. The use of the CNT-TNP electrode layer coated on FTO glass significantly improves the light intensity performance.
ACCEPTED MANUSCRIPT Keywords: Carbon nanotubes/TiO2 nanoparticles; TiO2 nanoparticles; Ru(II) complex;
PT
electrochemical luminescence (ECL) cell.
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Abstract code: AP5
SC
1. Introduction
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Among various light-emitting technologies, electrochemi-luminescence (ECL) has been developed high luminescence efficiency, simplified optical configuration, and cost-effectiveness
MA
for manufacturing [1,2]. The ECL cell is an emission phenomenon’s electrochemical by injecting electrons into between electron and light emitting material. The ECL cell devices are a simple
TE
D
structure which consists of the two conductive electrodes and the light-emitting layer, which injected in the between two electrodes. The conductive electrodes use transparent conductive
AC CE P
oxide (TCO) glass and the light-emitting layer use Ru(II) complex, it was widely used due to the strong light intensity and use low applied voltage [3,4]. Furthermore, in the addition of the oxide material electrodes deposited on TCO glass which can improve the light emission performance of the ECL cell device. Takase et al, [5] used TiO2 nanoparticle (TNP) grown on TCO glass was confirmed the high emission efficiency of the ECL cell with TNP (rutile and anatase). Moon et al, [6] presented nanostructure TiO2/Ti film deposited on TCO glass was found high luminance efficiency of the ECL cell with TiO2/Ti film. However, the TNP-coated TCO glass has still leakage and long-term stability problems [7]. The application of the most carbon nanotube (CNT) electrodes was widely used for electrogenerated chemiluminescence sensor due to it is a semiconductor and high electrical conductivity [8-11]. The CNT is formed from carbon atoms arranged in the sheet, which has a
ACCEPTED MANUSCRIPT high fluidity. CNT is similar to the structure of graphite. The CNT is coherence into a lattice with hexagonal holes, which is a pipe or a tube [12]. CNT is very small tubes about nanometer
PT
scale, which has a diameter of tubes in the range of 0.4 to 4.0 nm and band gaps 0.5 eV. It can
RI
be synthesized by two types; a single wall carbon nanotube (SWCNT) and a multi-wall carbon
SC
nanotube (MWCNT) [13]. Thus, we are focusing on ECL cell device with CNT-TNP composite in the type of SWCNT which may be increased the oxidation and reduction reaction of Ru(II)
NU
complex and recombination between Ru(I) and Ru(III), thus the overall conversion efficiency can increase.
MA
In this work, we report an ECL cells synthesized using CNT-TNP nanocomposite electrode. The CNT-TNP electrode coated on TCO glass can be increased the surface area interface with
TE
D
the Ru(II) complex. The structure of ECL cell with CNT-TNP consists of TCO glass/ CNT-TNP electrode/ Ru(II) complex/ TCO glass. The CNT-TNP synthesis has been mixed CNT and TNP
AC CE P
in 10:90 of ratio. The applied CNT-TNP electrode can improve luminance efficiency and long lifetime of the ECL cell.
2. Experiment Methods
Fig. 1 shows schematic of the ECL cell with the CNT-TNP electrode layer which distance between the two TCO glass layers of the cell was 60 m. FTO glass was used TCO glass because of its excellent conductive that prevents further problems. The production method is described below. The electrode layer was coated with CNT-TNP 30 m thickness by using thermos-plastic sealing films, on one side of the FTO glass in the ECL cell. The Ru(II) complex was injected into the surface between the CNT-TNP electrode layer and the FTO glass.
ACCEPTED MANUSCRIPT The synthesis of CNT can be discussed in previous reports [14]. The CNTs solution was fabricated CNTs (muti-wall nanotube: MWNT; Hanwha Naonotech) powder and sodium
PT
dodecylbenzene sulfonate (SDBS; CHEMMAX) by mixing in the ratio 20 mg : 20 mg, and the
RI
deionized water of 20 ml for surfactant, stirred 10 minutes. The dispersion of CNTs was prepared by bath sonicator (Branson, 2510) for 5 min and bar sonicator (Sonics & material,
SC
VCX500) for 20 min [15,16].
NU
The TNP was prepared as a form of a paste using the anatase TiO2 powder. First, add 2.5 g of TiO2 into a mixture of 10 mL of α-Terpineol (KENTO Chemical) and 50 mL of ethanol 99.9 %.
MA
And mix them thoroughly with an ultrasonic cleaner. Then, add ethyl cellulose of 1.5 g little by little by using a binder and applying 40 C heats for 1 h, one can disperse ethyl cellulose in the
TE
D
solution. So, one makes all reagents diluted in the solution. After an evaporator is used, the TNP solution and CNT solution mixed in ratio 90:10 wt% for tested. The CNT-TNP solution coated
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on FTO glass at size 11 cm2 by doctor blade method and heat treatment at 450C in 30 min. The ECL cell was fabricated Ru(bpy)3Cl2 (SIGMA-Aldrich) and NH4PF6 (WAKO) and propylene carbonate (PC; SIGMA-Aldrich). Ru(bpy)3(FP6)2 to synthesized via mixing Ru(bpy)3Cl2 and NH4PF6 (0.5 g : 0.5 g) in aqueous solution, stirring process to the solution for 1 h, and was dried under vacuum for 24 h. The Ru(bpy)3(FP6)2 powder and PC solution ratio was achieved at 0.04 g : 0.448 g. The fabricated ECL cell in this experiment was attached to the sealing machine (area of 11 cm2), and Ru(bpy)3 (FP6)2 was injected between FTO glasses, to finish the process.
ACCEPTED MANUSCRIPT 3. Results and discussion We prepared the ECL cell with the CNT-TNP electrode layer. The structural properties of
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CNT-TNP electrode were measured field emission scanning electron microscope (FE-SEM;
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Hitachi S-3000H). Figure 2 shows Top view and cross-sectional view SEM image of the CNTTNP films on the FTO glass. Figure 2(a) shows the CNT-TNP with cross-sectional view SEM
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image. In order to obtain a thickness of the CNT-TNP films was controlled to 30 µm following
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optimum conditions. The TNPs were a mix on the CNTs. The high magnification image of the CNT-TNP films showed the aggregation and adhesion of the TNP into CNT, as it seen in Fig.
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2(a) inset. Figure 2(b) shows top view surface of the CNT-TNP, was very rough and rounded on the surface.
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The luminance properties of ECL cell with CNT-TNT electrode layer measured by the spectral brightness analyzer (Konica Minota, CS-200A). The ECL cell represents electrode
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material, thus sample CNT-TNP electrodes have the following configurations: FTO Glass/ Ru(II)/ CNT-TNP (10µm)/ FTO Glass, FTO Glass/ Ru(II)/ TNPs (10µm)/ FTO Glass and FTO Glass/ Ru(II)/ FTO Glass, respectively. The light emission spectra of the ECL cells with TNP, CNT-TNP, and bare FTO are shown in Fig. 3. The peak intensity was 622 nm of the wavelengths which was not influenced to all electrodes by the operation condition of ECL devices at 4 V AC, 60 Hz. All electrodes of the ECL cells were showed responds dark orange emission of the ECL cell and confirmed not to influence ECL device’s luminous color. The luminance of the ECL cell with CNT-TNP, TNPs, and bare FTO are shown in Fig 4. When the applied AC voltage on the cell is 0 to 5.0 V peak and 60 Hz. The threshold voltage of the initial light emission was 2.25 V for CNT-TNP less than 2.5 V for TNP and 3.0 V for bare FTO electrodes. The intensity of the ECL cell was 59 cd/m2 for CNT-TNP, 50.8 cd/m2 for TNP,
ACCEPTED MANUSCRIPT and 23 cd/m2 for bare FTO electrodes. The best of the threshold voltage of the initial light emission and intensity were CNT-TNP films, due to the mean free path of the positive charge
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and a negative charge radicals in the CNT-TNP electrode causing the electrons fast transfer to
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Ru(bpy)32+ increase. Thus, the efficient current injection from CNT-TNP (the low threshold voltage) and the large contact area on the surface of the TNP.
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For, the electrical properties of the ECL cells with CNT-TNP film were measured by the
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sheet resistance meter (Dasol Eng, FPP-H8), a digital function generator (Agilent 33250A) and digital storage oscilloscope (Tektronix DPO 3034). The sheet resistance (Ω/sq) of the TNP and
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CNT-TNP films was measured on the surface area of TNP, CNT-TNP, and bare FTO (11 cm2 of the area). The sheet resistance of the TNPs was 7.79 Ω/sq, 7.63 Ω/sq for CNT-TNP, and 8.89
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Ω/sq for bare FTO. The sheet resistance of CNT-TNP was less than that TNP and bare FTO due
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to CNT-TNP was high porosity in the three dimensions interfaces with a large amount of
The current and voltage (I-V curve) of the ECL cells used by CNT-TNP, TNP, and bare FTO electrode are shown in Fig. 5. The output current of the ECL cell with CNT-TNP electrode was 65.24 mA, 58.13 mA for TNP and 40.21 mA for bare FTO electrodes, at 4.0 V. The best of the current was CNT-TNP due to the sheet resistance of the CNT-TNP less than TNP electrode. The power efficiency of the ECL cell can be known performances light intensity per electrical power (lm/W) [17-19]. Figure 6 is shown ECL efficiencies of the ECL cell with CNTTNP, TNP, and bare FTO electrode. The ECL efficiency of the ECL cell with CNT-TNP was 0.13615 lm/W more than 0.13137 lm/W for TNP at 4.0 V and 0.10213 lm/W for bare FTO electrode at 4.75 V. The highest ECL efficiency of the ECL cell with CNT-TNP electrode can be explained by increase the amount of the electrons on large surface of the CNT-TNP electrode
ACCEPTED MANUSCRIPT layer. The ECL efficiency of the used CNT-TNP, TNP, and bare FTO electrode were decreased because of the voltage increases, causing the high-density electrons flow through the region in
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large numbers on the surface of the electrodes and Ru(II). The optimum applied a voltage of
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ECL cells was 4.0 V.
3. Conclusion
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The effect of the electrical and optical characteristics of the ECL cell is using CNT-TNP electrode. The CNT-TNP electrode was compared a TNP and bare electrode. All characteristics
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of the ECL cells with each electrode can show the following: 1. At the voltage 4.0 V 60 Hz, the luminance properties of the ECL cell with CNT-TNP
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electrode was 59 cd/m2 which more than 50.8 cd/m2 for TNP and 23 cd/m2 for bare FTO electrode. The highest peak intensity of the ECL cell was CNT-TNP at wavelength 622 nm and
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show response dark-orange color.
2. At 4.0 V, the electrical properties (I-V curve) of the ECL cell with CNT-TNP, TNP and bare FTO electrode was 65.24 mA, 58.13mA and 40.21 mA, respectively. The ECL cell with CNT-TNP electrode was higher than all electrodes. 3. The ECL efficiency of the ECL cell with CNT-TNP was 0.13615 lm/W more than that TNP and bare FTO electrode. Considering, the optimum all properties of the each electrode are CNT-TNP electrode. Applying the CNT-TNP film electrode layer on the ECL cell increased the interface area of the electrode, it may increase transfer oxidation/reduction reaction of the Ru(II) complex, which results in significant increase of ECL cell efficiency.
ACCEPTED MANUSCRIPT Acknowledgements This research (Grants No.C0193902) was supported by Business for Academic-industrial
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Cooperative establishments funded by Korea Small and Medium Business Administration in
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2015.
ACCEPTED MANUSCRIPT References [1] M. M. Richter, Electrochemiluminescence (ECL), Chem. Rev. 104 (2004) 3003-3036.
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[2] A. J. Bard and L. R. Faulkner: Electrochemical Methods Fundamentals and Applications
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(Wiley, New York, 2001) P.15.
[3] H.Rudmann, S. Shinada and M. F. Rubner, Solid-state light-emitting devices based on the
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tris-chelated ruthenium(II) complex. 4. High-efficiency light-emitting devices based on
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derivatives of the tris(2,2 '-bipyridyl) ruthenium(II) complex, J. Am. Chem. Soc. 124 (2002) 4918 – 4921.
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[4] T. Kado, M. Takenouchi, S. Okamoto, W. Takashima, K. Kaketo, and A. Hayase, Enhanced Electrochemi luminescence by Use of Nanoporous TiO2 Electrodes: Electrochemiluminescence
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Devices Operated with Alternating Current, Jpn. J Appl. phys. 44 (2005) 8161-8164. [5] M. Takase, S. Sugimoto, K. Nakamura, and N. Kobayashi, Effect of TiO2 Nanoparticle on
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[6] B. H. Moon, D. J Kwak, Y. M Sung, “Optical and Electrochemical Characteristics of Nanostructural TiO2/Ti/ Glass Electrode,” Inter. J. Theo. Appl. Nanotech., vol.1, issue 1, pp.8669, 2012.
[7] H.M. Kwon, C.H. Han, Y.M. Sung, Fabrication of High Efficiency Electrochemiluminescence Cell with Nanocrystalline TiO2 Electrode, Trans KIEE 59 (2010) 363–368. [8] H. N. Choi, J. Y. Lee, Y. K. Lyu, W. Y. Lee, Tris(2,2-bipyridyl)ruthenium(II) electrogenerated chemiluminescence sensor based on carbon nantube dispersed in sol–gelderived titania–Nafion composite films, Analytica Chimica Acta 565 (2006) 48–55.
ACCEPTED MANUSCRIPT [9] L. Shen, J. Li, L. Li, G. Zou, X. Zhang, W. Jin, Ultrasensitive electrochemiluminescence method for determination of DNA using Ru(bpy)32+-coated magnetic submicrobeads wrapped
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[11] A. T. Lawal, Synthesis and utilization of carbon nanotubes for fabrication of electrochemical biosensors, Mater. Res. Bull. 73 (2016) 308-350.
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[14] E. Kymakis, M. M. Stylianakis, G. D. Spyropoulos, E. Stratakis, E. Koudoumas, and C. Fotakis, “Spin coated carbon nanotubes as the hole trans port layer inorganic photovoltaics,” Solar Energy Materials & Solar Cells, vol. 96, pp.298–301, 2012. [15]
Ray H. Baughman, Anvar A. Zakhidov, Walt A. de Heer, “Carbon nanotubes-the route
toward applications,” Science, vol.297, pp.787–792, 2002. [16] Yu Jin Kang, Haegeun Chung, Chi-Hwan Han, Woong Kim, “All-solid-state flexible supercapacitors based on papers coated with carbon nanotubes and ionic-liquid-based gel electrolytes,” Nanotechnology, vol. 23, no. 6, pp. 065401, 2012. [17] H. D. Park, Y. M. Sung, M. W. Park, J. E. Song, “Comparison
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ACCEPTED MANUSCRIPT [18] P. Chansri, Y. M. Sumg, “Synthesis and characterization of TiO2 on ZnO-nanorod layer for high-efficiency electrochemiluminescence cell application”, Jpn. J Appl. phys. 55 (2016) 02BB1
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[19] P. Chansri, Y. M. Sumg, “Investigations of electrochemical luminescence characteristics of ZnO/TiO2 nanotubes electrode and silica-based gel type solvents”, Surface & Coatings
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ACCEPTED MANUSCRIPT Figure Captions Fig. 1 Schematic of ECL cell with CNT-TNP electrode.
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Fig. 2 SEM image of CNT-TNP film (a) cross-sectional view (b) top view.
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Fig. 3 Spectral brightness intensity of ECL cell with CNT-TNP, TNP and bare FTO.
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Fig. 4 Light intensity of ECL cell with CNT-TNP, TNP and bare FTO. Fig. 5 I-V curve of ECL cell with CNT-TNP, TNP and bare FTO.
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Fig. 6 ECL intensity of ECL cell with CNT-TNP, TNP and bare FTO.
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Fig. 1 Schematic of ECL cell with CNT-TNP electrode.
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Highlights
The minimum threshold voltage at light emission start was 2.25 V for CNT-TNP electr ode.
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A simple preparation process for advanced ECL cell using carbon nanotube/TiO2 nanopartic le (CNT-TNP). The CNT-TNP was fabricated by mixture ratio TNP = 90 wt% : CNT = 10wt%
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The electrical and optical properties of the ECL cell with CNT-TNP electrode were 59 cd /m2 for light intensity, 65.24 mA for output current, and 0.13615 lm/W for ECL effici ency At 4 V 60 Hz (1×1 cm2 of area size).