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Enhanced water oxidation efficiency of hematite thin films by oxygen-deficient atmosphere

Published online by Cambridge University Press:  09 December 2015

André L.M. Freitas ,
Waldemir M. Carvalho Jr.  and
Flavio L. Souza
André L.M. Freitas
Affiliation:
Laboratory of Alternative Energy and Nanomaterial (LEAN), Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do ABC (UFABC), Santo André, São Paulo 09210-580, Brazil
Waldemir M. Carvalho Jr.
Affiliation:
Laboratory of Alternative Energy and Nanomaterial (LEAN), Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do ABC (UFABC), Santo André, São Paulo 09210-580, Brazil
Flavio L. Souza*
Affiliation:
Laboratory of Alternative Energy and Nanomaterial (LEAN), Centro de Ciências Naturais e Humanas (CCNH), Universidade Federal do ABC (UFABC), Santo André, São Paulo 09210-580, Brazil
*
a)Address all correspondence to this author. e-mail: [email protected] or [email protected]
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Abstract

This work describes the effects of different atmospheres used during the thermal treatment of hematite films synthesized on transparent conductive substrates of fluorine-doped tin oxide by a newly reported wet chemical route assisted by microwave. The as-synthesized films were subjected to additional thermal treatment at 750 °C for 30 min in different gas flux (air, O2, and N2) to obtain a desirable phase and surface activation. A series of techniques were used to elucidate effects of each atmosphere used during the thermal treatment. The morphology of the films, as analyzed by top-view and cross-sectional scanning electron microscopy images, showed no significant changes and was composed of rods homogeneously distributed over the substrate, which covered the immersed area with a thickness between 98 and 100 nm. The photoelectrochemical response of the N2-hematite films was found to be 80 and 50% more efficient at 1.23 VRHE (reversible hydrogen electrode) than those of films produced in air and an O2 atmosphere. The photocurrent enhancement achieved by treatment in an oxygen-deficient atmosphere was attributed to the improvement of hematite catalytic activity, which produced a hematite–electrolyte interface favorable for water oxidation. Since an increase in the donor density by one order of magnitude was found for the N2-hematite films, a reduction of charge transfer resistance was expected in these films. However, the Nyquist plot analysis showed that the O2-hematite film had a lower charge transfer resistance. As a result, it is impossible to relate the photocurrent enhancement observed in N2-hematite film to electronic changes or vacancy formation, as previously reported in the literature. Indeed, by performing photoelectrochemical measurements in the presence of hole scavengers, it became clear that the major improvement caused by the oxygen-deficient atmosphere was in the catalytic activity efficiency of the hematite films for water oxidation. It was found that the oxygen-deficient atmosphere could improve the overall photoelectrochemical performance of the hematite by acting as a hole scavengers. This finding contrasts with a previous report, in which the use of an oxygen-deficient atmosphere during the phase transformation from akaganeite to hematite was found to enhance the photocurrent density by inducing an increased donor density caused by the formation of vacancies [Y. Ling et al., Angew. Chem., Int. Ed.51, 4074 (2012)].

Keywords

hematite thin filmmicrowave-assisted hydrothermal processthermal treatment conditionssurface activityphotoelectrochemical response
Type
Invited Feature Paper
Information
Journal of Materials Research , Volume 30 , Issue 23 , 14 December 2015 , pp. 3595 - 3604
Copyright
Copyright © Materials Research Society 2015 

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References

REFERENCES

Walter, M.G., Warren, E.L., McKone, J.R., Boettcher, S.W., Mi, Q., Santori, E.A., and Lewis, N.S.: Solar water splitting cells. Chem. Rev. 110(11), 6446 (2010).Google Scholar
Cook, T.R., Dogutan, D.K., Reece, S.Y., Surendranath, Y., Teets, T.S., and Nocera, D.G.: Solar energy supply and storage for the legacy and nonlegacy worlds. Chem. Rev. 110(11), 6474 (2010).Google Scholar
Katz, M.J., Riha, S.C., Jeong, N.C., Martinson, A.B.F., Farha, O.K., and Hupp, J.T.: Toward solar fuels: Water splitting with sunlight and “rust”? Coord. Chem. Rev. 256(21–22), 2521 (2012).Google Scholar
Maeda, K.: Photocatalytic water splitting using semiconductor particles: History and recent developments. J. Photochem. Photobiol., C 12(4), 237 (2011).Google Scholar
Kronawitter, C.X., Vayssieres, L., Shen, S., Guo, L., Wheeler, D.A., Zhang, J.Z., Antoun, B.R., and Mao, S.S.: A perspective on solar-driven water splitting with all-oxide hetero-nanostructures. Energy Environ. Sci. 4, 3889 (2011).CrossRefGoogle Scholar
Valdés, Á., Brillet, J., Grätzel, M., Gudmundsdóttir, H., Hansen, H.A., Jónsson, H., Klüpfel, P., Kroes, G-J., Le Formal, F., Man, I.C., Martins, R.S., Nørskov, J.K., Rossmeisl, J., Sivula, K., Vojvodic, A., and Zäch, M.: Solar hydrogen production with semiconductor metal oxides: New directions in experiment and theory. Phys. Chem. Chem. Phys. 14, 49 (2012).Google Scholar
Navarro, R.M., Alvarez-Galvan, M.C., Villoria de la Mano, J.A., Al-Zahrani, S.M., and Fierro, J.L.G.: A framework for visible-light water splitting. Energy Environ. Sci. 3(12), 1865 (2010).Google Scholar
van de Krol, R., Liang, Y., and Schoonman, J.: Solar hydrogen production with nanostructured metal oxides. J. Mater. Chem. 18(20), 2311 (2008).CrossRefGoogle Scholar
Alexander, B.D., Kulesza, P.J., Rutkowska, I., Solarska, R., and Augustynski, J.: Metal oxide photoanodes for solar hydrogen production. J. Mater. Chem. 18(20), 2298 (2008).CrossRefGoogle Scholar
Shankar, K., Basham, J.I., Allam, N.K., Varghese, O.K., Mor, G.K., Feng, X., Paulose, M., Seabold, J.A., Choi, K-S., and Grimes, C.A.: Recent advances in the Use of TiO2 nanotube and nanowire arrays for oxidative photoelectrochemistry. J. Phys. Chem. C 113(16), 6327 (2009).CrossRefGoogle Scholar
Sivula, K., Le Formal, F., and Grätzel, M.: Solar water splitting: Progress using hematite (α-Fe2O3) photoelectrodes. ChemSusChem 4(4), 432 (2011).CrossRefGoogle Scholar
Tachibana, Y., Vayssieres, L., and Durrant, J.R.: Artificial photosynthesis for solar water-splitting. Nat. Photonics 6(8), 511 (2012).Google Scholar
Hardee, K.L. and Bard, A.J.: Semiconductor electrodes. V. The application of chemically vapor deposited iron oxide films to photosensitized electrolysis. J. Electrochem. Soc. 123, 1024 (1976).CrossRefGoogle Scholar
Hardee, K.L. and Bard, A.J.: Semiconductor electrodes. X. Photoelectrochemical behavior of several polycrystalline metal oxide electrodes in aqueous solutions. J. Electrochem. Soc. 124(2), 215 (1977).CrossRefGoogle Scholar
Bjoerksten, U., Moser, J., and Graetzel, M.: Photoelectrochemical studies on nanocrystalline hematite films. Chem. Mater. 6(6), 858 (1994).Google Scholar
Souza, F.L., Lopes, K.P., Longo, E., and Leite, E.R.: The influence of the film thickness of nanostructured α-Fe2O3 on water photooxidation. Phys. Chem. Chem. Phys. 11, 1215 (2009).CrossRefGoogle ScholarPubMed
Souza, F.L., Lopes, K.P., Nascente, P.A.P., and Leite, E.R.: Nanostructured hematite thin films produced by spin-coating deposition solution: Application in water splitting. Sol. Energy Mater. Sol. Cells 93(3), 362 (2009).CrossRefGoogle Scholar
Gonçalves, R.H., Lima, B.H.R., and Leite, E.R.: Magnetite colloidal nanocrystals: A facile pathway to prepare mesoporous hematite thin films for photoelectrochemical water splitting. J. Am. Chem. Soc. 133(15), 6012 (2011).CrossRefGoogle ScholarPubMed
Sivula, K., Zboril, R., Le Formal, F., Robert, R., Weidenkaff, A., Tucek, J., Frydrych, J., and Grätzel, M.: Photoelectrochemical water splitting with mesoporous hematite prepared by a solution-based colloidal approach. J. Am. Chem. Soc. 132(21), 7436 (2010).Google Scholar
Brillet, J., Grätzel, M., and Sivula, K.: Decoupling feature size and functionality in solution-processed, porous hematite electrodes for solar water splitting. Nano Lett. 10(10), 4155 (2010).Google Scholar
Kay, A., Cesar, I., and Grätzel, M.: New benchmark for water photooxidation by nanostructured α-Fe2O3 films. J. Am. Chem. Soc. 128(49), 15714 (2006).CrossRefGoogle ScholarPubMed
Cesar, I., Kay, A., Gonzalez Martinez, J.A., and Grätzel, M.: Translucent thin film Fe2O3 photoanodes for efficient water splitting by sunlight: Nanostructure-directing effect of Si-doping. J. Am. Chem. Soc. 128(14), 4582 (2006).Google Scholar
Hisatomi, T., Brillet, J., Cornuz, M., Le Formal, F., Tetreault, N., Sivula, K., and Grätzel, M.: A Ga2O3 underlayer as an isomorphic template for ultrathin hematite films toward efficient photoelectrochemical water splitting. Faraday Discuss. 155, 223 (2012).Google Scholar
Hisatomi, T., Dotan, H., Stefik, M., Sivula, K., Rothschild, A., Grätzel, M., and Mathews, N.: Enhancement in the performance of ultrathin hematite photoanode for water splitting by an oxide underlayer. Adv. Mater. 24(20), 2699 (2012).Google Scholar
Vayssieres, L., Beermann, N., Lindquist, S.E., and Hagfeldt, A.: Controlled aqueous chemical growth of oriented three-dimensional crystalline nanorod arrays: Application to iron(III) oxides. Chem. Mater. 13(2), 233 (2001).Google Scholar
Beermann, N., Vayssieres, L., Lindquist, S-E., and Hagfeldt, A.: Photoelectrochemical studies of oriented nanorod thin films of hematite. J. Electrochem. Soc. 147(7), 2456 (2000).Google Scholar
Vayssieres, L., Sathe, C., Butorin, S.M., Shuh, D.K., Nordgren, J., and Guo, J.: One-dimensional quantum-confinement effect in α-Fe2O3 ultrafine nanorod arrays. Adv. Mater. 17(19), 2320 (2005).Google Scholar
Morrish, R., Rahman, M., MacElroy, J.M.D., and Wolden, C.A.: Activation of hematite nanorod arrays for photoelectrochemical water splitting. ChemSusChem 4(4), 474 (2011).Google Scholar
Bora, D.K., Braun, A., Erni, R., Fortunato, G., Graule, T., and Constable, E.C.: Hydrothermal treatment of a hematite film leads to highly oriented faceted nanostructures with enhanced photocurrents. Chem. Mater. 23(8), 2051 (2011).Google Scholar
de Carvalho, V.A.N., Luz, R.A.S., Lima, B.H., Crespilho, F.N., Leite, E.R., and Souza, F.L.: Highly oriented hematite nanorods arrays for photoelectrochemical water splitting. J. Power Sources 205, 525 (2012).Google Scholar
Ferraz, L.C., Carvalho, W.M. Jr., Criado, D., and Souza, F.L.: Vertically oriented iron oxide films produced by hydrothermal process: Effect of thermal treatment on the physical chemical properties. ACS Appl. Mater. Interfaces 4(10), 5515 (2012).Google Scholar
Cornuz, M., Grätzel, M., and Kevin, S.: Preferential orientation in hematite films for solar hydrogen production via water splitting. Chem. Vap. Deposition 16(10–12), 291 (2010).CrossRefGoogle Scholar
Goncalves, R.H. and Leite, E.R.: The colloidal nanocrystal deposition process: An advanced method to prepare high performance hematite photoanodes for water splitting. Energy Environ. Sci. 7(7), 2250 (2014).CrossRefGoogle Scholar
Warren, S.C., Voïtchovsky, K., Dotan, H., Leroy, C.M., Cornuz, M., Stellacci, F., Hébert, C., Rothschild, A., and Grätzel, M.: Identifying champion nanostructures for solar water-splitting. Nat. Mater. 12, 842 (2013).Google Scholar
Kronawitter, C.X., Bakke, J.R., Wheeler, D.A., Wang, W-C., Chang, C., Antoun, B.R., Zhang, J.Z., Guo, J., Bent, S.F., Mao, S.S., and Vayssieres, L.: Electron enrichment in 3d transition metal oxide hetero-nanostructures. Nano Lett. 11(9), 3855 (2011).Google Scholar
Xi, L., Tran, P.D., Chiam, S.Y., Bassi, P.S., Mak, W.F., Mulmudi, H.K., Batabyal, S.K., Barber, J., Loo, J.S.C., and Wong, L.H.: Co3O4-Decorated hematite nanorods As an effective photoanode for solar water oxidation. J. Phys. Chem. C 116(26), 13884 (2012).Google Scholar
Shen, S., Kronawitter, C.X., Wheeler, D.A., Guo, P., Lindley, S.A., Jiang, J., Zhang, J.Z., Guo, L., and Mao, S.S.: Physical and photoelectrochemical characterization of Ti-doped hematite photoanodes prepared by solution growth. J. Mater. Chem. A 1(46), 14498 (2013).Google Scholar
Mao, A., Kim, J.K., Shin, K., Wang, D.H., Yoo, P.J., Han, G.Y., and Park, J.H.: Hematite modified tungsten trioxide nanoparticle photoanode for solar water oxidation. J. Power Sources 210, 32 (2012).Google Scholar
Steier, L., Herraiz-Cardona, I., Gimenez, S., Fabregat-Santiago, F., Bisquert, J., Tilley, S.D., and Grätzel, M.: Understanding the role of underlayers and overlayers in thin film hematite photoanodes. Adv. Funct. Mater. 24(48), 7681 (2014).CrossRefGoogle Scholar
Carvalho, W.M. Jr. and Souza, F.L.: Recent advances on solar water splitting using hematite nanorod film produced by purpose-built material methods. J. Mater. Res. 29(01), 16 (2014).Google Scholar
Goncalves, R.H. and Leite, E.R.: Nanostructural characterization of mesoporous hematite thin film photoanode used for water splitting. J. Mater. Res. 29(01), 47 (2014).Google Scholar
Cesar, I., Sivula, K., Kay, A., Zboril, R., and Grätzel, M.: Influence of feature size, film thickness, and silicon doping on the performance of nanostructured hematite photoanodes for solar water splitting. J. Phys. Chem. C 113(2), 772 (2008).Google Scholar
Gan, J., Lu, X., and Tong, Y.: Towards highly efficient photoanodes: Boosting sunlight-driven semiconductor nanomaterials for water oxidation. Nanoscale 6(13), 7142 (2014).CrossRefGoogle ScholarPubMed
Ling, Y., Wang, G., Reddy, J., Wang, C., Zhang, J.Z., and Li, Y.: The influence of oxygen content on the thermal activation of hematite nanowires. Angew. Chem., Int. Ed. 51(17), 4074 (2012).Google Scholar
Forster, M., Potter, R.J., Ling, Y., Yang, Y., Klug, D.R., Li, Y., and Cowan, A.J.: Oxygen deficient α-Fe2O3 photoelectrodes: A balance between enhanced electrical properties and trap-mediated losses. Chem. Sci. 6(7), 4009 (2015).Google Scholar
Xavier, A.M., Ferreira, F.F., and Souza, F.L.: Morphological and structural evolution from akaganeite to hematite of nanorods monitored by ex situ synchrotron X-ray powder diffraction. RSC Adv. 4(34), 17753 (2014).CrossRefGoogle Scholar
Cunha, D.M. and Souza, F.L.: Facile synthetic route for producing one-dimensional zinc oxide nanoflowers and characterization of their optical properties. J. Alloys Compd. 577, 158 (2013).CrossRefGoogle Scholar
Ami, T. and Suzuki, M.: MOCVD growth of (100)-oriented CeO2 thin films on hydrogen-terminated Si(100) substrates. Mater. Sci. Eng., B 54(1–2), 84 (1998).Google Scholar
Shen, S., Kronawitter, C.X., Jiang, J., Mao, S.S., and Guo, L.: Surface tuning for promoted charge transfer in hematite nanorod arrays as water-splitting photoanodes. Nano Res. 5(5), 327 (2012).CrossRefGoogle Scholar
Rasband, W.: ImageJ (Bethesda, MD: National Institutes of Health, 2015).Google Scholar
Anpo, M. and Takeuchi, M.: The design and development of highly reactive titanium oxide photocatalysts operating under visible light irradiation. J. Catal. 216(1–2), 505 (2003).CrossRefGoogle Scholar
Pan, X., Yang, M-Q., Fu, X., Zhang, N., and Xu, Y-J.: Defective TiO2 with oxygen vacancies: Synthesis, properties and photocatalytic applications. Nanoscale 5(9), 3601 (2013).Google Scholar
van de Krol, R. and Gratzel, M.: Photoelectrochemical Hydrogen Production (New York: Springer Science, 2012).CrossRefGoogle Scholar
Lopes, T., Andrade, L., Le Formal, F., Gratzel, M., Sivula, K., and Mendes, A.: Hematite photoelectrodes for water splitting: Evaluation of the role of film thickness by impedance spectroscopy. Phys. Chem. Chem. Phys. 16(31), 16515 (2014).Google Scholar
Sivula, K.: Metal oxide photoelectrodes for solar fuel production, surface traps, and catalysis. J. Phys. Chem. Lett. 4(10), 1624−1633 (2013).Google Scholar
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