Growing need for cleaner environment and energy production has brought about a hunt for perspective materials. One of such perspective materials is titanium dioxide (TiO2, titania) due to its chemical stability and photocatalytic properties. Titania can be synthesized through many methods but anodization process is one of the prevailing methods to produce high active surface nanostructured titania. Various anodization electrolytes produce different polymorphs of TiO2. Uniform phase distribution on the surface is crucial for higher photocatalytic activity. In this research, the influence of two electrolytes on polymorph phase distribution of TiO2 was investigated. Phase distribution correlation with optical band gap, charge density and photocurrent values were tested. Successful Raman investigation of anodized titania revealed uniform, single and multi-phase, as well as nonuniform phase distributions produced respectively in PO43‒ and SO42‒ ions containing electrolytes. Uniform single phase titania shows highest photocurrent (PCR) and charge density values compared to phase composition and nonuniform phase distributions. We have shown Raman microprobe analysis as indispensable method for wholesome sample characteristics.
1. Dai, Y. and Gao, H. O. Energy consumption in China’s logistics industry: A decomposition analysis using the LMDI approach. Transp. Res. Part D Transp. Environ., 2016, 46, 69–80.
https://doi.org/10.1016/j.trd.2016.03.003
2. International Energy Agency. Key world energy statistics. 2016.
3. Xu, B. and Lin, B. Assessing CO2 emissions in China’s iron and steel industry: a dynamic vector autoregression model. Appl. Energy, 2016, 161, 375–386.
https://doi.org/10.1016/j.apenergy.2015.10.039
4. Lin, B. and Xie, C. Reduction potential of CO2 emissions in China’s transport industry. Renew. Sustain. Energy Rev. 2014, 33, 689–700.
https://doi.org/10.1016/j.rser.2014.02.017
5. Geng, C., Chen, J., Yang, X., Ren, L., Yin, B., Liu, X., et al. Emission factors of polycyclic aromatic hydrocarbons from domestic coal combustion in China. J. Environ. Sci., 2014, 26(1), 160–166.
https://doi.org/10.1016/S1001-0742(13)60393-9
6. Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions: a European Strategy for Low-Emission Mobility. European Commission, Brussels, 2016, SWD (2016) 244.
7. Chatterjee, D. and Dasgupta, S. Visible light induced photocatalytic degradation of organic pollutants. J. Photochem. Photobiol. C Photochem. Rev., 2005, 6(2–3), 186–205.
8. Kmentova, H., Kment, S., Wang, L., Pausova, S., Vaclavu, T., Kuzel, R., et al. Photoelectrochemical and structural properties of TiO2 nanotubes and nanorods grown on FTO substrate: Comparative study between electrochemical anodization and hydrothermal method used for the nanostructures fabrication. Catal. Today, 2016, 287, 130–136.
https://doi.org/10.1016/j.cattod.2016.10.022
9. Akple, M. S., Low, J., Qin, Z., Wageh, S., Al-Ghamdi, A. A., Yu, J., et al. Nitrogen-doped TiO2 microsheets with enhanced visible light photocatalytic activity for CO2 reduction. Chinese J. Catal., 2015, 36(12), 2127–2134.
https://doi.org/10.1016/S1872-2067(15)60989-5
10. Civiš, S., Ferus, M., Knížek, A., Kubelík, P., Kavan, L., and Zukalová, M. Photocatalytic transformation of CO2 to CH4 and CO on acidic surface of TiO2 anatase. Opt. Mater., 2015, 56, 80–83.
https://doi.org/10.1016/j.optmat.2015.11.015
11. Fujishima, A. and Honda, K. Electrochemical photolysis of water at a semiconductor electrode. Nature, 1972, 238(5358), 37–38.
https://doi.org/10.1038/238037a0
12. Hanaor. D. A. H. and Sorrell, C. C. Review of the anatase to rutile phase transformation. J. Mater. Sci., 2011, 46(4), 855–874.
https://doi.org/10.1007/s10853-010-5113-0
13. Zaman, A. C., Üstündağ, C. B., Kaya, F., and Kaya, C. Synthesis and electrophoretic deposition of hydrothermally synthesized multilayer TiO2 nanotubes on conductive filters. Mater. Lett., 2012, 66(1), 179–181.
https://doi.org/10.1016/j.matlet.2011.08.020
14. Daviðsdóttir, S., Canulescu, S., Dirscherl, K., Schou, J., and Ambat, R. Investigation of photocatalytic activity of titanium dioxide deposited on metallic substrates by DC magnetron sputtering. Surf. Coatings Technol., 2013, 216, 35–45.
https://doi.org/10.1016/j.surfcoat.2012.11.015
15. Oja, I., Mere, A., Krunks, M., Solterbeck, C.-H., and Es-Souni, M. Properties of TiO2 Films Prepared by the Spray Pyrolysis Method. Solid State Phenom., 2004, 99, 259–264.
https://doi.org/10.4028/www.scientific.net/SSP.99-100.259
16. Varghese, O. K., Gong, D., Paulose, M., Grimes, C. A., and Dickey, E. C. Crystallization and high-temperature structural stability of titanium oxide nanotube arrays. J. Mater. Chem., 1998, 8, 1731–1734.
17. Hasan, M. M., Haseeb, A. S. M. A., Saidur, R., and Masjuki, H. H. Effects of annealing treatment on optical properties of anatase TiO2 thin films. Int. J. Mech. Aerosp. Ind. Mechatr. Manuf. Eng., 2008, 2, 410–414.
18. Mor, G. K., Varghese, O. K., Paulose, M., Shankar, K., and Grimes, C. A. A review on highly ordered, vertically oriented TiO2 nanotube arrays: fabrication, material properties, and solar energy applications. Sol. Energy Mater. Sol. Cells., 2006, 90(14), 2011–2075.
https://doi.org/10.1016/j.solmat.2006.04.007
19. Yuangpho, N., Le, S. T. T., Treerujiraphapong, T., Khanitchaidecha, W., and Nakaruk, A. Enhanced photocatalytic performance of TiO2 particles via effect of anatase–rutile ratio. Phys. E. Low Dimens. Syst. Nanostruct., 2015, 67, 18–22.
https://doi.org/10.1016/j.physe.2014.11.006
20. Grimes, C. A. and Mor, G. K. 2009. TiO2 nanotube arrays. MA: Springer US, Boston.
https://doi.org/10.1007/978-1-4419-0068-5
21. Regonini, D., Bowen, C. R., Jaroenworaluck, A., and Stevens, R. A review of growth mechanism, structure and crystallinity of anodized TiO2 nanotubes. Mater. Sci. Eng. R. Reports, 2013, 74(12), 377–406.
https://doi.org/10.1016/j.mser.2013.10.001
22. Roy, P., Berger, S., Schmuki, P., and Schmuki, P. TiO2 nanotubes: synthesis and applications. Angew. Chem. Int. Ed., 2011, 50, 2904–2939.
https://doi.org/10.1002/anie.201001374
23. Kubelka, P. New Contributions to the optics of intensely light-scattering materials. Part I. J. Opt. Soc. Am., 1948, 38(5), 448.
https://doi.org/10.1364/JOSA.38.000448
24. Kubelka, P. New contributions to the optics of intensely light-scattering materials. Part II: nonhomogeneous layers. J. Opt. Soc. Am., 1954, 44(4), 330.
https://doi.org/10.1364/JOSA.44.000330
25. Cronemeyer, D. C. and Gilleo, M. A. The optical absorption and photoconductivity of rutile. Phys. Rev., 1951, 82(6), 975–976.
https://doi.org/10.1103/PhysRev.82.975
26. Scanlon, D. O., Dunnill, C. W., Buckeridge, J., Shevlin, S. A., Logsdail, A. J., Woodley, S. M., et al. Band alignment of rutile and anatase TiO2. Nat. Mater., 2013, 12(9), 798–801.
https://doi.org/10.1038/nmat3697
27. Beranek, R. (Photo)electrochemical methods for the determination of the band edge positions of TiO2-based nanomaterials. Adv. Phys. Chem., 2011, 80–83.
https://doi.org/10.1155/2011/786759
28. Sellers, M. C. K. and Seebauer, E. G. Measurement method for carrier concentration in TiO2 via the Mott-Schottky approach. Thin Sol. Films., 2011, 519(7), 2103–2110.
https://doi.org/10.1016/j.tsf.2010.10.071
