Abstract
In the present study, high-yield W18O49@TiO2 core–shell nanoparticles were prepared by modified plasma arc gas condensation without any catalysts or substrates. All the as-prepared samples were characterized by FEG-SEM, XRD, FEG-STEM, and HAADF analytic techniques. The results of the structural analysis show that the as-prepared nanoparticles presenting a core–shell morphology with an average diameter of 43.5 ± 8.0 nm were composed of non-stoichiometric tungsten oxide (W18O49 phase) as the core (20–40 nm) and rutile-phase TiO2 as the shell with non-uniform thickness (10–20 nm). For the optical properties of the as-prepared W18O49@TiO2 core–shell nanoparticles, Raman spectroscopy and photoluminescence (PL) spectra were used. Compared with pure TiO2 and W18O49 nanocrystals, the experimental results reveal that the defects in the lattice between the core and shell layers induced the board and shifted peaks in Raman spectra. Also, W18O49@TiO2 core–shell nanoparticles exhibited green emission at 483 nm wavelength observed in PL spectrum. Thermal gravimetric analyzer (TGA) results indicate that the TiO2 shell served a stable layer and prevented further oxidation from the atmosphere of the W18O49 core, thereby improving the thermal stability of W18O49 nanoparticles.
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Allain E, Besson S, Durand C, Moreau M, Gacoin T, Boilot JP (2007) Transparent mesoporous nanocomposite films for self-cleaning applications. Adv Funct Mater 17:549–554. doi:10.1002/adfm.200600197
Amin S, Nicholls AW, Xu TT (2007) A facile approach to synthesize single-crystalline rutile TiO2 one-dimensional nanostructures. Nanotechnology 18:445609. doi:10.1088/0957-4484/18/44/445609
Cheng P, Deng C, Dai X, Li B, Liu D, Xu J (2008) Enhanced energy conversion efficiency of TiO2 electrode modified with WO3 in dye-sensitized solar cells. J Photochem Photobio A 195:144–150. doi:10.1016/j.jphotochem.2007.09.016
Comini E (2006) Metal oxide nano-crystals for gas sensing. Anal Chim Acta 568:28–40. doi:10.1016/j.aca.2005.10.069
Fujishima A, Zhang X, Tryk DA (2008) TiO2 photocatalysis and related surface phenomena. Surf Sci Rep 63:515–582. doi:10.1016/j.surfrep.2008.10.001
Kowalska E, Remita H, Colbeau-Justin C, Hupka J, Belloni J (2008) Modification of titanium dioxide with platinum ions and clusters: application in photocatalysis. J Phys Chem C 112:1124–1131. doi:10.1021/jp077466p
Kuang Q, Jiang ZY, Xie ZX, Lin SC, Lin ZW, Xie SY, Huang RB, Zheng LS (2005) Tailoring the optical property by a three-dimensional epitaxial heterostructure: a case of ZnO/SnO2. J Am Chem Soc 127:11777–11784. doi:10.1021/ja052259t
Li H, Bian Z, Zhu J, Huo Y, Li H, Lu Y (2007a) Mesoporous Au/TiO2 nanocomposites with enhanced photocatalytic activity. J Am Chem Soc 129:4538–4539. doi:10.1021/ja069113u
Li Y, Xu G, Zhu YL, Ma XL, Cheng HM (2007b) SnO2/In2O3 one-dimensional nano-core–shell structures: synthesis, characterization and photoluminescence properties. Solid State Commun 142:441–444. doi:10.1016/j.ssc.2007.03.031
Liu DY, Chen J, Zhou J, Deng SZ, Xu NS, Xu JB (2007a) Raman spectroscopic study of oxidation and phase transition in W18O49 nanowires. J Raman Spectrosc 38:176–180. doi:10.1002/jrs.1620
Liu Z, Sun DD, Guo P, Leckie JO (2007b) An efficient bicomponent TiO2/SnO2 nanofiber photocatalyst fabricated by electrospinning with a side-by-side dual spinneret method. Nano Lett 7:1081–1085. doi:10.1021/nl061898e
Ni M, Leung MKH, Leung DYC, Sumathy K (2007) A review and recent developments in photocatalytic water-splitting using TiO2 for hydrogen production. Renew Sust Energ Rev 11:401–425. doi:10.1016/j.rser.2005.01.009
Niklasson GA, Granqvist CG (2007) Electrochromics for smart windows: thin films of tungsten oxide and nickel oxide, and devices based on these. J Mater Chem 17:127–156. doi:10.1039/b612174h
Norman JH, Staley HG (1965) Thermodynamics of the dimerization and trimerization of gaseous tungsten trioxide and molybdenum trioxide. J Chem Phys 43:3804–3806. doi:10.1063/1.1696565
Saito Y (1995) Nanoparticles and filled nanocapsules. Carbon 33:979–988. doi:10.1016/0008-6223(95)00026-A
Seto T, Akinaga H, Takano F, Koga K, Orii T, Hirasawa M (2005) Magnetic properties of monodispersed Ni/NiO core–shell nanoparticles. J Phys Chem B 109:13403–13405. doi:10.1021/jp052084
Smith W, Zhao YP (2009) Superior photocatalytic performance by vertically aligned core–shell TiO2/WO3 nanorod arrays. Catal Commun 10:1117–1121. doi:#10.1016/j.catcom.2009.01.010
Su CY, Lin HC (2009) Direct route to tungsten oxide nanorod bundles: microstructures and electro-optical properties. J Phys Chem C 113:4042–4046. doi:10.1021/jp809458j
Su CY, Lin HC, Lin W, Lin CK (2007) Formation of tungsten oxide encapsulated in titanium oxide nanocages by modified plasma arc gas condensation. Nanotechnology 18:155602–155606. doi:10.1088/0957-4484/18/15/155602
Su CY, Lin CK, Yang TK, Lin HC, Pan CT (2008) Oxygen partial pressure effect on the preparation of nanocrystalline tungsten oxide powders by a plasma arc gas condensation technique. Int J Refract Met Hard Mat 26:423–428. doi:10.1016/j.ijrmhm.2007.09.006
Su CY, Lin HC, Yang TK, Lin CK (2010) Structure and optical properties of tungsten oxide nanomaterials prepared by a modified plasma arc gas condensation technique. J Nanopart Res 12:1755–1763. doi:10.1007/s11051-009-9730-y
Vanheusden K, Warren WL, Seager CH, Tallant DR, Voigt JA, Gnade BE (1996) Mechanisms behind green photoluminescence in ZnO phosphor powders. J Appl Phys 79:7983–7990. doi:10.1063/1.362349
Wang XP, Yang Q, Zhang HX, Feng PX (2007) Tungsten oxide nanorods array and nanobundle prepared by using chemical vapor deposition technique. Nanoscale Res Lett 2:405–409. doi:10.1007/s11671-007-9075-3
Yamashita H, Ichihashi Y, Zhang SG, Matrumura Y, Souma Y, Tatsumi T, Anpo M (1997) Photocatalytic decomposition of NO at 275 K on titanium oxide catalysts anchored within zeolite cavities and framework. Appl Surf Sci 121/122:305–309. doi:10.1016/S0169-4332(97)00311-5
Yang XL, Dai WL, Guo C, Chen H, Cao Y, Li X, He H, Fan K (2005) Synthesis of novel core-shell structured WO3/TiO2 spheroids and its application in the catalytic oxidation of cyclopentene to glutaraldehyde by aqueous H2O2. J Catal 234:438–450. doi:10.1016/j.jcat.2005.06.035
Zheng H, Li J, Wang ZL, Liu JP, Su S (2004) Bimagnetic core/shell FePt/Fe3O4 nanoparticles. Nano Lett 4:187–190. doi:10.1021/nl035004r
Zhou J, Ding Y, Deng SZ, Gong L, Xu XS, Wang ZL (2005a) Three-dimensional tungsten oxide nanowire networks. Adv Mater 17:2107–2110. doi:10.1002/adma.200500885
Zhou J, Gong L, Deng SZ, Chen J, She JC, Xu XS, Yang R, Wang ZL (2005b) Growth and field-emission property of tungsten oxide nanotip arrays. Appl Phys Lett 87:223108. doi:10.1063/1.2136006
Acknowledgments
This study was supported by the National Science Council of Taiwan under contract no. NSC 98-2221-E-027 -035 -MY3. The authors would also like to thank Ms. Laing-Chu Wang for her technical assistance on field-emission gun scanning transmission electron microscope.
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Lin, HC., Su, CY. & Lin, CK. High-yield fabrication of W18O49@TiO2 core–shell nanoparticles: microstructures and optical-thermal properties. J Nanopart Res 13, 4549–4555 (2011). https://doi.org/10.1007/s11051-011-0411-2
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DOI: https://doi.org/10.1007/s11051-011-0411-2