Synthesis and Electrochemical Properties of Transparent Nanostructured BaTiO₃ Film Electrodes

Hongjun Wang^*, Xinhua Cao, Fangke Liu, Shupei Guo, Xinxin Ren, Shuming Yang

College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang, China.

DOI: 10.4236/ojic.2015.52005                

Abstract

Transparent nanostructured BaTiO3 film electrodes were synthesized on conductive substrates from BaTiO₃ nanocrystals forming at low temperature. Electrochemical and spectroelectrochemical methods were employed to investigate its properties of band energetics and the trap state at different pH values. The flat band edges greatly depended on the pH value of electrolyte, and the flat band edges were -0.70, -0.92 and -1.20 V vs saturated Ag/AgCl at the pH value of 3.0, 6.8 and 13.0, respectively. The results showed that trap state densities also highly depended on pH. The total trap state densities were 3.73 × 10¹⁵, 4.02 × 10¹⁵ and 6.48 × 10¹⁶ cm^-2 at pH value of 3.0, 6.8 and 13.0 respectively with maximum located at -0.36 V, -0.50 V and -0.80 V. The results obtained from CVs were in good agreement with that obtained from the measurements of time resolved currents. The size of the peak potentials in the cyclic voltammograms experiments was increased dramatically with the pH value increasing, indicating that traps were surface-related.

Keywords

Nanostructured BaTiO₃ Film, Electrochemistry, Spectroelectrochemistry, Band Energetics, Trap State

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	O’Regan, B. and Gratzel, M. (1991) A Low-Cost, High-Efficiency Solar Cell Based on Dye-Sensitized Colloidal TiO2 Films. Nature, 353, 3737-3740. http://dx.doi.org/10.1038/353737a0
[2]	Murayama, M. and Mori, T. (2008) Novel Tandem Cell Structure of Dye-Sensitized Solar Cell for Improvement in Photocurrent. Thin Solid Films, 516, 2716-2722. http://dx.doi.org/10.1016/j.tsf.2007.04.076
[3]	Liu, J., Yang, H.T., Zhou, X.W. and Lin, Y. (2011) Photovoltaic Performance Improvement of Dye-Sensitized Solar Cells Based on Tantalum-Doped TiO2 Thin Films. Electrochimica Acta, 56, 396-400. http://dx.doi.org/10.1016/j.electacta.2010.08.063
[4]	Hauch, A. and Georg, A. (2001) Diffusion in the Electrolyte and Charge-Transfer Reaction at the Platinum Electrode in Dye-Sensitized Solar Cells. Electrochimica Acta, 46, 3457-3466. http://dx.doi.org/10.1016/S0013-4686(01)00540-0
[5]	Gratzel, M. (2005) Solar Energy Conversion by Dye-Sensitized Photovoltaic Cells. Inorganic Chemistry, 44, 6841- 6851. http://dx.doi.org/10.1021/ic0508371
[6]	van de Lagemaat, J., Park, N.G., Frank, A.J., Boschloo, G.K. and Goossens, A.J. (2000) Influence of Electrical Potential Distribution, Charge Transport, and Recombination on the Photopotential and Photocurrent Conversion Efficiency of Dye-Sensitized Nanocrystalline TiO2 Solar Cells:A Study by Electrical Impedance and Optical Modulation Techniques. The Journal of Physical Chemistry B, 104, 2044-2052. http://dx.doi.org/10.1021/jp993172v
[7]	Cinnsealach, R., Boschloo, G., Rao, S.N. and Fitzmaurice, D. (1999) Coloured Electrochromic Windows Based on Nanostructured TiO2 Films Modified by Adsorbed Redox Chromophores. Solar Energy Materials and Solar Cells, 57, 107-125. http://dx.doi.org/10.1016/S0927-0248(98)00156-1
[8]	Razykov, T.M., Ferekides, C.S., Morel, D., Stefanakos, E., Ullal, H.S. and Upadhyaya, H.M. (2011) Solar Photovoltaic Electricity: Current Status and Future Prospects. Solar Energy, 85, 1580-1608. http://dx.doi.org/10.1016/j.solener.2010.12.002
[9]	Beermann, N., Boschloo, G., Holmberg, A. and Hagfeldt, A.J. (2002) Trapping of Electrons in Nanostructured TiO2 Studied by Photocurrent Transients. Journal of Photochemistry and Photobiology A: Chemistry, 152, 213-218. http://dx.doi.org/10.1016/S1010-6030(02)00236-8
[10]	Enright, B. and Fitzmaurice, D. (1996) Spectroscopic Determination of Electron and Hole Effective Masses in a Nanocrystalline Semiconductor Film. The Journal of Physical Chemistry, 100, 1027-1035. http://dx.doi.org/10.1021/jp951142w
[11]	Fu, Z.W., Huang, F., Zhang, Y., Chu Y. and Qin, Q.Z. (2003) The Electrochemical Reaction of Zinc Oxide Thin Films with Lithium. Journal of Electrochemical Society, 150, A714-A720. http://dx.doi.org/10.1149/1.1570410
[12]	Yang, S.M., Kou, H.Z., Wang, H.J., Cheng K. and Wang, J.C. (2010) Preparation and Band Energetics of Transparent Nanostructured SrTiO3 Film Electrodes. The Journal of Physical Chemistry C, 114, 815-819. http://dx.doi.org/10.1021/jp910204q
[13]	O’Regan, B., Moser, J., Anderson M. and Gratzel, M. (1990) Vectorial Electron Injection into Transparent Semiconductor Membranes and Electric Field Effects on the Dynamics of Light-Induced Charge Separation. The Journal of Physical Chemistry, 94, 8720-8726. http://dx.doi.org/10.1021/j100387a017
[14]	Wang, H., Hagfeldt, A., Lindquist, S.E., Boschloo, G. and Lindstrom, H. (2001) Electrochemical Investigation of Traps in a Nanostructured TiO2 Film. The Journal of Physical Chemistry B, 105, 2529-2533. http://dx.doi.org/10.1021/jp0036083
[15]	Ma, B., Bai J.C., and Dong , L.F. (2013) Electrochemical Impedance Analysis of Methanol Oxidation on Carbon Nanotube-Supported Pt and Pt-Ru Nanoparticles. Journal of Solid State Electrochemistry, 17, 2783-2788. http://dx.doi.org/10.1007/s10008-013-2177-1
[16]	Juodkazis, K., Juodkazyte, J., Sebeka, B., Savickaja, I. and Juodkazis, S. (2013) Photoelectrochemistry of Silicon in HF Solution. Journal of Solid State Electrochemistry, 17, 2269-2276. http://dx.doi.org/10.1007/s10008-013-2064-9
[17]	Juodkazis, K., Juodkazyte, J., Kalinauskas, P., Gertus, T., Jelmakas, E., Misawa, H. and Juodkazis, S. (2010) Influence of Laser Microfabrication on Silicon Electrochemical Behavior in HF Solution. Journal of Solid State Electrochemistry, 14, 797-802. http://dx.doi.org/10.1007/s10008-009-0852-z
[18]	Badawy, W.A. (2008) Effect of Porous Silicon Layer on the Performance of Si/Oxide Photovoltaic and Photoelectrochemical Cells. Journal of Alloys and Compounds, 464, 347-351. http://dx.doi.org/10.1016/j.jallcom.2007.09.122
[19]	da Silva, L.F., Maia, L.J.Q., Bernardi, M.I.B., Andres J.A. and Mastelaro, V.R. (2011) An Improved Method for Preparation of SrTiO3 Nanoparticles. Materials Chemistry and Physics, 125, 168-173. http://dx.doi.org/10.1016/j.matchemphys.2010.09.001
[20]	Yang, S.M., Kou, H.Z., Wang, H.J. and Xue, H.B. (2010) Tunability of the Band Energetics of Nanostructured SrTiO3 Electrodes for Dye-Sensitized Solar Cells. The Journal of Physical Chemistry C, 114, 4245-4249. http://dx.doi.org/10.1021/jp9117979
[21]	Xu, J.B., Zhai, J.W., Yao, X., Xue, J.Q. and Huang, Z.M. (2007) Dielectric and Optical Properties of BaTiO3 Thin Films Prepared by Low-Temperature Process. Journal of Sol-Gel Science and Technology, 42, 209-212. http://link.springer.com/article/10.1007/s10971-007-0740-x
[22]	Shen, Z.G., Zhang, W.W., Hen J.F. and Jimmy, Y. (2006) Low Temperature One Step Synthesis of Barium Titanate: Particle Formation Mechanism and Large-Scale Synthesis. Chinese Journal of Chemical Engineering, 14, 642-648. http://dx.doi.org/10.1016/S1004-9541(06)60128-6
[23]	Barbe, C.J., Arendse, F., Comte, P., Jirousek, M., Lenzmann, F., Shklover, V. and Gratzel, M. (1997) Nanocrystalline Titanium Oxide Electrodes for Photovoltaic Applications. Journal of the American Ceramic Society, 80, 3157-3171. http://onlinelibrary.wiley.com/doi/10.1111/j.1151-2916.1997.tb03245.x/citedby
[24]	Sikora, E., Sikora, J. and Macdonald, D.D. (1996) A New Method for Estimating the Diffusivities of Vacancies in Passive Films. Electrochimica Acta, 41, 783-789. http://dx.doi.org/10.1016/0013-4686(95)00312-6
[25]	Kavan, L., Kratochvilova, K., and Gratzel, M. (1995) Study of Nanocrystalline TiO2 (Anatase) Electrode in the Accumulation Regime. Journal of Electroanalytical Chemistry, 394, 93-102. http://dx.doi.org/10.1016/0022-0728(95)03976-N
[26]	Kavan, L., Gratzel, M., Rathousky, J. and Zukal, A. (1996) Nanocrystalline TiO2 (Anatase) Electrodes: Surface Morphology, Adsorption, and Electrochemical Properties. Journal of Electrochemical Society, 143, 394-400. http://dx.doi.org/10.1149/1.1836455