Efficient Photoelectrochemical Splitting of Water to H2 and O2 at Nanocrystalline Carbon Modified (CM)-n-TiO2 Thin Films

Article Preview

Abstract:

The carbon modified n-type titanium oxide (CM-n-TiO2) thin films were synthesized by flame oxidation of Ti metal sheets both flat and grooved and also by using combination of spray pyrolysis and flame oxidation of flat surface. Also undoped reference n-TiO2samples were also synthesized in an electric oven for comparison. Photoresponse of CM-n-TiO2 and n-TiO2 were evaluated by measuring the rates of water splitting to hydrogen and oxygen, in terms of observed photocurrent densities. Under the white light illumination of intensity of 100 mW cm-2 from the xenon lamp the photocurrent densities were found to be 1.60, 9.17, 11.44 and 14.68 mA cm-2 for optimized oven made n-TiO2 (sample1), flame made on flat surface (sample 2), on grooved surface (sample 3) and spray pyrolysis-flame made CM-n-TiO2 (sample 4) thin films at 0.477 V, 0.240 V, 0.242 V and 0.215 V biases respectively. The corresponding maximum photoconversion efficiencies for these thin films were found to be 1.2 %, 9.08 %, 11.31 % and 14.04 % for samples 1-4 respectively. Under monochromatic light illumination from the xenon lamp the maximum photoconversion efficiencies for samples 1-4 were found to be 0.94 %, 8.86 %, 11.16 % and 13.79 % respectively. However, under actual natural global AM 1.5 sunlight illumination of 1 sun, the maximum photoconversion efficiencies reduced to 0.67 %, 5.63 %, 7.62 % and 12.26 % for samples 1, 2, 4 and 3 respectively. These values compared well with those found under monochromatic light illumination from the xenon lamp. The increasing efficiencies were found consistent with lowering of band gaps from 2.9 eV for sample 1 to 2.65 eV and generation of mid-gap band at 1.6 eV for both samples 2 and 3 and 1.4 eV above the valence band for sample 4. Carbon contents were found to be 0.0, 17.60, 19.38 and 23.23 atom % for samples 1, 2, 3 and 4 respectively.

You might also be interested in these eBooks

Info:

Periodical:

Solid State Phenomena (Volume 162)

Pages:

179-201

Citation:

Online since:

June 2010

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2010 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] S.U.M. Khan, M. Al-Shahry, W.B. Ingler Jr., Science 297 (2002) 2243.

Google Scholar

[2] S. Licht, B. Wang, S. Mukerji, T. Soga, M. Umeno, H. Tributsch, J. Phys. Chem. B 104 (2000) 8920.

Google Scholar

[3] Khaselev, J.R. Turner, Science 280 (1998) 425.

Google Scholar

[4] S.U.M. Khan, J. Akikusa, J. Phys. Chem. B 103 (1999) 7184.

Google Scholar

[5] S.U.M. Khan, J. Akikusa, J. Electrochem. Soc. 145 (1998) 89.

Google Scholar

[6] J. Akikusa, S.U.M. Khan, Int. J. Hyd. Ener. 22 (1997) 875.

Google Scholar

[7] S.A. Majumder, S.U.M. Khan. Int. J. Hyd. Ener. 19 (1994) 881.

Google Scholar

[8] Srivastava, R.K. Karn, M. Misra. Int. J. Hyd. Ener. 25 (2000) 495.

Google Scholar

[9] T. Bak, J. Nowotny, M. Rekas, C.C. Sorrel. Int. J. Hyd. Ener. 27 (2002) 19.

Google Scholar

[10] Akikusa, S.U.M. Khan. Int. J. Hyd. Ener. 27 (2002) 863.

Google Scholar

[11] J.G. Yu, H.G. Yu, B. Cheng, X.J. Zhao, J.C. Yu, W.K. Ho. J. Phys. Chem. B 107 (2003) 13871.

Google Scholar

[12] N. Serpone, E. Pelizzetti. Photocatalysis: Fundamentals and Applications; Wiley: New York, (1989).

Google Scholar

[13] J. Nowotny, T. Back, M.K. Nowotny, R.L. Sheppard, Intl. J. Hydrogen Energy, 32 (2007) 2609.

Google Scholar

[14] S.K. Mohaputra, V.K. Mahajan, M. Mishra, Nanotechnology, 18 (2007) 445705.

Google Scholar

[15] C. C. Fa, L. Y. Lang, H.S. Weng, Nanotechnology, 19 (2008) 125704.

Google Scholar

[16] C. Xu, S.U.M. Khan. Electrochem. Solid -State Lett. 10 (2007) B56.

Google Scholar

[17] C. Xu, K Richard, L.G. McMahan, S.U.M. Khan. Electrochem. Commun. 8 (2006) 1650.

Google Scholar

[18] S.K. Mohaputra, M. Mishra, V.K. Mahajan, J. Phys. Chem C, 111 (2007) 8677.

Google Scholar

[19] K. Noworyta, J. Augustynski, Electrochem. Solid-State Lett. 7 (2004) E31.

Google Scholar

[20] Y. A. Shaban, S. U. M. Khan, Int. J. Hydrogen Energy 33, (2008) 1118.

Google Scholar

[21] Y. A. Shaban, S. U. M. Khan, Chemical Physics 339 (2007) 73.

Google Scholar

[22] Y. A. Shaban, S. U. M. Khan, J. Solid State Electrochemistry, accepted, (2008).

Google Scholar

[23] Y. Li, D. S. Hwang, N. H. Lee, S. J. Kim, Chem. Phys. Lett., 404 (2005) 25.

Google Scholar

[24] Choi, A. Termin, M.R. Hoffman, J. Phys. Chem. 98 (1994) 13669.

Google Scholar

[25] M. Anpo, Catal. Surv. Jpn. 1 (1997) 169.

Google Scholar

[26] Choi, T. Umebayashi, M. Yoshikawa, J. Mater. Sci. 39 (2004) 1837.

Google Scholar

[27] E. Barborini, A.M. Conti, I. Kholmanov, P. Piseri, A. Podesta, P. Milani, C. Cepek, O. Sakho, R. Macovez, M. Sancrotti, Adv. Mater. 17 (2005) 1842.

DOI: 10.1002/adma.200401169

Google Scholar

[28] D. Noguchi, Y. Kawanata, and T. Nagatomo, J. Electrochem. Soc. 152 (2005) D124.

Google Scholar

[29] C. Xu, R. Killmeyer, M.L. Gray, and S.U.M. Khan, Applied Catalysis B: Environmental 64 (2006) 312.

Google Scholar

[30] H. Irie, Y. Watanabe, K. Hashimoto, Chemistry Letters 32 (2003) 72.

Google Scholar

[31] S. Sakthivel, H. Kisch, Angew. Chem. Int. Ed. 42 (2003) 4908.

Google Scholar

[32] R. Asahi, T. Morikawa, T. Ohwaki, K. Aoki, Y. Taga, Science 293 (2001) 269.

Google Scholar

[33] Y.C. Hong, C.U. Bang, D.H. Shin, H.S. Uhm, Chem. Phys. Lett. 413 (2005) 454.

Google Scholar

[34] T. Umebayashi, T. Yamaki, H. Itoh, and K. Asai, Applied Physics Letters 81 (2002) 454.

Google Scholar

[35] J. Tang, Y. Wu, W. McFarland, G.D. Stucky, Chem. Commun. (2004) 1670.

Google Scholar

[36] H. Choi, E. Stathatos, D.D. Dionysiou, Applied Catalysis, B: Environmental 63 (2006) 60.

Google Scholar

[37] G. K. Mor, K. Shankar, M. Paulose, O.K. Varghese, C.A. Grimes, Nano Letters 5 (2005) 191.

Google Scholar

[38] J. H. Park, S. Kim, and A.J. Bard, Nano Letters 6 (2006) 24.

Google Scholar

[39] K. Shankar, M. Paulose, G.K. Mor, O.K. Varghese, C.A. Grimes, J. Phys. D: Appl. Phys. 38 (2005) 3543.

Google Scholar

[40] C. Xu, Y.A. Shaban, W.B. Ingler Jr., S.U.M. Khan, ECS Transactions 3 (2006) 65.

Google Scholar

[41] C. Xu, Y.A. Shaban, W.B. Ingler Jr., S.U.M. Khan, Sol. Energy Mat. Sol. Cells 91 (2007) 938.

Google Scholar

[42] R. Hahn, A. Ghicov, J. Salonen, V-P. Lehto and P. Schmuki, Nanotechnology 18 (2007) 105604.

DOI: 10.1088/0957-4484/18/10/105604

Google Scholar

[43] Y. Nakano, T. Morikawa, T. Ohwaki, Y. Taga, Appl. Phys. Lett. 87 (2005) 052111.

Google Scholar

[44] W. Ren, Z. Ai, F. Jia , L. Zhang, X. Fan, Z. Zou, Applied Catalysis B: Environmental 69 (2007) 138-144.

Google Scholar

[45] X. Nie, K. Sohlberg, Materials Research Society Symposium Proceedings on Materials and Technology for Hydrogen Economy. 801 (2004) 205.

Google Scholar

[46] H. Wang and J.P. Lewis, J. Phys.: Condens. Matter 17 (2005) L209.

Google Scholar

[47] H. Wang and J.P. Lewis, J. Phys.: Condens. Matter 18 (2006) 421.

Google Scholar

[48] C. Di. Valentin, G. Pacchioni, A. Selloni, Chem. Mater. 17 (2005) 6656.

Google Scholar

[49] C. Hägglund, M. Grätzel, T. Kansemo, Science 301 (2003) 1673b.

Google Scholar

[50] B. Murphy, P.R. F. Barnes, L.K. Randeniya, I.C. Plumb, I. E. Grey, M.D. Horne, J.A. Glasscock, Int. J. Hydrogen Energy 31 (2006) (1999).

DOI: 10.1016/j.ijhydene.2006.01.014

Google Scholar

[51] Information on http: /www. nrel. gov.

Google Scholar

[52] R. D. Schaller, V. I. Klimov,. Phys. Rev. Lett. 92 (2004) 186601.

Google Scholar

[53] R. J. Ellingson, M. C. Beard, J. C. Johnson, J. C.; Yu, P.; Micic, O. I.

Google Scholar

[54] J. Nozik,., A. Shabaev, Al. L. Efros, . �ano Lett. 5 (2005) 865.

Google Scholar

[55] R. D. Schaller, M. Sykora, J. M. Pietryga, V. I. Klimov, �ano Lett. 6 ( 2006) 424.

Google Scholar

[56] J. E. Murphy, M. C. Beard, A. G. Norman, S. P. Ahrenkiev, J. C. Johnson, P. Yu, O. I. Micic, R. J. Ellingson, A. J. Nozik, J. Am. Chem. Soc. 128 (2006) 3241.

Google Scholar

[57] Shabaev, Al. L. Efros, A. J. Nozik, �ano Lett. 6 (2006) 2856.

Google Scholar

[58] J. Nozik, Physica E. 14 (2002) 115.

Google Scholar

[59] P. Gleckman, J. O'Gallagher, R. Winston, �ature, 339 (1989) 198.

Google Scholar