Abstract
Photocatalysts based on mixtures of rutile and anatase forms of titania usually show a better catalytic performance than each individual component. In order to understand this behavior, several experimental and theoretical approaches have been proposed in the past, looking for an adequate reference frame for aligning energy bands, and arriving sometimes to opposite results. In this work, the theoretical results obtained for the band alignment applying a modified common anion rule for different possibilities of mixed-phase (anatase–rutile) interaction are presented. According to our results, mixed-phase systems involve the transfer of electrons from rutile to anatase and holes from anatase to rutile. This analysis would be applicable to real samples of mixed phase of titania with large particle size. However, for heterogeneous size particulate systems, it is not only necessary to consider the alignment of bands of the bulk system, but also those of the corresponding surfaces. In keeping with the analysis performed, the best mixed systems are those composed by large particles of both polymorphs or by small particles of anatase dissolved in rutile. Our results could explain the disagreement found in the literature regarding the experimental works.
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Liu, G., Wang, L., Yang, H., Cheng, H., Qing, G.: Titania-based photocatalysts-crystal growth, doping and heterostructuring. J. Mater. Chem. 20, 831–843 (2010)
Stafford, U., Gray, K., Kamat, P., Varma, A.: An in situ diffuse reflectance FTIR investigation of photocatalytic degradation of 4-chlorophenol on a TiO2 powder surface. Chem. Phys. Lett. 205, 55–61 (1993)
Ohno, T., Tokieda, K., Matsumura, M.: Morphology of a TiO2 photocatalyst (Degussa, P-25) consisting of anatase and rutile crystalline phases. J. Catal. 203, 82–86 (2001)
Ohno, T., Tokieda, K., Higashida, S., Matsumara, M.: Synergism between rutile and anatase TiO2 particles in photocatalytic oxidation of naphthalene. Appl. Catal. A Gen. 244, 383–391 (2003)
Leung, D., Fu, X., Wang, C., Ni, M., Leung, M., Wang, X., Fu, X.: Hydrogen production over titania-based photocatalysts. Chem. Sus. Chem. 3, 681–694 (2010)
Yu, E.T., Mc Caldin, J.O., Mc Gill, T.C.: Band offsets in semiconductor heterojunctions. Solid State Phys. 46, 1–146 (1992)
Milnes, A.G., Feucht, D.L.: Heterojunctions and Metal-Semiconductor Junctions. Academic Press, New York (1972)
Mc Caldin, J.O., Mc Gill, T.C., Mead, C.A.: Correlation for III-V and II-VI semiconductors of the Au Schottky barrier energy with anion electronegativity. Phys. Rev. Lett. 36, 56 (1976)
Harrison, W.A., Tersoff, J.: Tight-binding theory of heterojunction band lineups and interface dipoles. J. Vac. Sci. Technol. B 4, 1068–1973 (1986)
Klein, A.: Energy band alignment at interfaces of semiconducting oxides: a review of experimental determination using photoelectron spectroscopy and comparison with theoretical predictions by the electron affinity rule, charge neutrality levels, and the common anion rule. Thin Solid Films 520, 3721–3728 (2012)
Wei, S.H., Zunger, A.: Calculated natural band offsets of all II–VI and III–V semiconductors: chemical trends and the role of cation d orbitals. Appl. Phys. Lett. 72, 2011–2013 (1998)
Späth, B., Fritsche, J., Säuberlich, F., Klein, A., Jaegermann, W.: Studies of sputtered ZnTe films as interlayer for the CdTe thin film solar cell. Thin Solid Films 480–481, 204 (2005)
Tersoff, J., Harrison, W.A.: Transition-metal impurities in semiconductors—their connection with band lineups and Schottky barriers. Phys. Rev. Lett. 58, 2367–2370 (1987)
Pfeifer, V., Erhart, P., Li, S., Rachut, K., Morasch, J., Bröntz, J., Reckers, P., Mayer, T., Rühle, S., Zaban, A., Seró, I., Bisquert, J., Jaegermenn, W., Klein, A.: Energy band alignment between anatase and rutile TiO2. J. Phys. Chem. Lett. 4, 4182–4187 (2013)
Ju, M.-G., Sun, G., Wang, J., Meng, Q., Liang, W.: Origin of high photocatalytic properties in the mixed-phase TiO2: a first-principles theoretical study. Appl. Mater. Interf. 6, 12885–12892 (2014)
Deák, P., Aradi, B., Frauenheim, T.: Band lineup and charge carrier separation in mixed rutile-anatase systems. J. Phys. Chem. C 115, 3443–3446 (2011)
Scanlon, D., Dunnill, Ch., Buckeridge, J., Shevlin, S., Logsdail, A., Woodley, S., Catlow, C., Powell, M., Palgrave, R., Parkin, I., Watson, G., Keal, T., Sherwood, P., Walsh, A., Sokol, A.: Band alignment of rutile and anatase TiO2. Nat. Mater. 12, 798–801 (2013)
Hurum, D.C., Gray, K.A., Rajh, T., Thurnauer, M.C.: Recombination pathways in the degussa P25 formulation of TiO2: surface versus lattice mechanisms. J. Phys. Chem. B 109, 977–980 (2005)
Shen, S., Wang, X., Chen, T., Feng, Z., Li, C.: Transfer of photoinduced electrons in anatase-rutile TiO2 determined by time-resolved mid-infrared spectroscopy. J. Phys. Chem. C 118, 12661–12668 (2014)
Kang, J., Wu, F., Li, S., Xia, J., Li, J.: Calculating band alignment between materials with different structures: the case of anatase and rutile titanium dioxide. J. Phys. Chem. C 116, 20765–20768 (2012)
Bickley, R., Gonzalez, Carreno J., Lees, S., Palmisano, L., Tilley, R.: A structural investigation of titanium dioxide photocatalysts. Solid State Chem. 92, 178–190 (1991)
Kresse, G.: Furthmüller: efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. J Phys. Rev. B 54, 11169–11186 (1996)
Dudarev, S., Botton, G., Savrasov, S., Humphreys, C., Sutton, A.: Electron-energy-loss spectra and the structural stability of nickel oxide: an LSDA+U study. Phys. Rev. B 57, 1505–1509 (1998)
Muscat, J., Swamy, V., Harrison, N.M.: First-principles calculations of the phase stability of TiO2. Phys. Rev. B 65, 224112–224115 (2002)
Morgade, C.I.N., Vignatti, ChI, Avila, M.S., Cabeza, G.F.: Theoretical and experimental analysis of the oxidation of CO on Pt catalysts supported on modified TiO2(101). J. Mol. Catal. A Chem. 407, 102–112 (2015)
Morgade, C.I.N., Cabeza, G.F.: Synergetic interplay between metal (Pt) and nonmetal (C) species in codoped TiO2: a DFT+U study. Comput. Mater. Sci. 111, 513–524 (2016)
Blochl, P.: Projector augmented-wave method. Phys. Rev. B 50, 17953–17979 (1994)
Perdew, J.P., Wang, Y.: Accurate and simple density functional for the electronic exchange energy: generalized gradient approximation. Phys. Rev. B 33, 8800(R) (1986)
Methfessel, M., Paxton, A.T.: High-precision sampling for Brillouin-zone integration in metals. Phys. Rev. B 40, 3616–3621 (1989)
Bader, R.F.W.: Atoms in Molecules: A Quantum Theory. Oxford University Press, Oxford (1990)
Xiong, G., Shao, R., Droubay, T., Joly, A., Beck, K., Chambers, S., Hess, W.: Photoemission electron microscopy of TiO2 anatase films embedded with rutile nanocrystals. Adv. Funct. Mater. 17, 2133–2138 (2007)
Hurum, D., Agrios, A.G., Gray, K.A.: Explaining the enhanced photocatalytic activity of degussa P25 mixed-phase TiO2 using EPR. J. Phys. Chem. B 107, 4545–4549 (2003)
Nosaka, Y., Nosaka, A.: Reconsideration of intrinsic band alignments within anatase and rutile TiO2. J. Phys. Chem. Lett. 7, 431–434 (2016)
Zhang, J., Xu, Q., Feng, Z., Li, M., Li, C.: Importance of the relationship between surface phases and photocatalytic activity of TiO2. Angew. Chem. Int. 47, 1766–1769 (2008)
Zhang, X., Lin, Y., He, D., Zhang, J., Fan, Z., Xie, T.: Interface junction at anatase/rutile in mixed-phase TiO2: formation and photo-generated charge carriers properties. Chem. Phys. Lett. 504, 71–75 (2011)
Cheng, H., Selloni, A.: Surface and subsurface oxygen vacancies in anatase TiO2 and differences with rutile. Phys. Rev. B 79, 092101–092104 (2009)
Zawadzki, P.: Absorption spectra of trapped holes in anatase TiO2. J. Phys. Chem. C 117, 8647–8651 (2013)
Mi, Y., Weng, Y.: Band alignment and controllable electron migration between rutile and anatase TiO2. Sci. Rep. 5, 11482 (2015)
Colbeau-Justin, C., Kunst, M., Huguenin, D.: Structural influence on charge-carrier lifetimes in TiO2 powders studied by microwave absorption. J. Mater. Sci. 38, 2429–2437 (2003)
Togo, A., Fumiyasu, O., Tanaka, I.: First-principles calculations of the ferroelastic transition between rutile-type and CaCl2-type SiO2 at high pressures. Phys. Rev. B. 78, 134106–134109 (2008)
Shomate, C.H.: Heat capacities at low temperatures of titanium dioxide (rutile and anatase). J. Am. Chem. Soc. 69, 218–219 (1947)
Shen, Q., Katayama, K., Sawada, T., Yamaguchi, M., Kumagai, Y., Toyoda, T.: Photoexcited hole dynamics in TiO2 nanocrystalline films characterized using a lens-free heterodyne detection transient grating technique. Chem. Phys. Lett. 419, 464–468 (2006)
Kavan, L., Gratzel, M., Gillert, S., Klemenz, C., Scheel, H.: Electrochemical and photoelectrochemical investigation of single-crystal anatase. J. Am. Chem. Soc. 115, 6716–6723 (1996)
Zhang, J., Zhou, P., Liu, J., Yu, J.: New understanding of the difference of photocatalytic activity among anatase, rutile and brookite TiO2. Phys. Chem. Chem. Phys. 16, 20382–20385 (2014)
Luttrell, T., Halpegamage, S., Tao, J., Kramer, A., Sutter, E., Batzill, M.: Why is anatase a better photocatalyst than rutile?—model studies on epitaxial TiO2 films. Sci. Rep. 4, 4043 (2014)
Li, G., Chen, L., Graham, M.E., Gray, K.A.: A comparison of mixed phase titania photocatalysts prepared by physical and chemical methods: the importance of the solid–solid interface. J. Mol. Catal. A Chem. 275, 30–35 (2007)
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The authors thank the financial support from the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and the Universidad Nacional del Sur (UNS) (PGI: 24/F068).
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Morgade, C.I.N., Castellani, N.J. & Cabeza, G.F. Theoretical analysis of band alignment and charge carriers migration in mixed-phase TiO2 systems. J Comput Electron 17, 1505–1514 (2018). https://doi.org/10.1007/s10825-018-1232-7
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DOI: https://doi.org/10.1007/s10825-018-1232-7