Preparation and characterisation of nanostructural TiO2–Er2O3 binary oxides with high surface area derived from particulate sol–gel route

Abstract Nanostructured and nanoporous TiO2–Er2O3 films and powders with various TiO2 : Er2O3 molar ratios and high specific surface area (SSA) have been prepared by a new straightforward particulate sol–gel route. X-ray diffraction and Fourier transform infrared spectroscopy revealed that erbium oxide formed in the range 50–100 mol.-%Er2O3, whereas erbium dititanate formed in the range 25–100 mol.-%Er2O3. Oxygen deficient titania phases (TiO2−x), such as Ti7O13 and Ti2O3, were observed for TiO2 : Er2O3=25 : 75 (molar ratio) system annealed at 800°C. It was observed that Er2O3 retarded anatase to rutile transformation. Furthermore, TEM analysis also showed that Er2O3 hindered the crystallisation and crystal growth of powders. Specific surface area of powders measured by Brunauer–Emmett–Teller analysis was enhanced by introducing Er2O3. TiO2 : Er2O3=25 : 75 (molar ratio) system annealed at 500°C produced the smallest crystallite size (1&middot2 nm), the smallest grain size (17 nm), the highest SSA (174 m2 g−1) and the highest roughness. TiO2 : Er2O3=50 : 50 (molar ratio) system annealed at 800°C showed the smallest crystallite size (4·3 nm), the highest SSA (44 m2 g−1), the highest roughness with 32 nm average grain size. One of the smallest crystallite sizes and one of the highest SSA reported in the literature are obtained, and they can be used in many applications in areas from optical electronics to gas sensors.

[1]  M. Ghorbani,et al.  Preparation of high surface area titania (TiO2) films and powders using particulate sol–gel route aided by polymeric fugitive agents , 2006 .

[2]  D. Fray,et al.  Synthesis of high surface area nanocrystalline anatase-TiO2 powders derived from particulate sol-gel route by tailoring processing parameters , 2006 .

[3]  Jun Lin,et al.  A simple method to synthesize β-Ga2O3 nanorods and their photoluminescence properties , 2005 .

[4]  Ataullah Khan,et al.  Stabilization of nanosized titania-anatase for high temperature catalytic applications , 2004 .

[5]  M. Mohseni,et al.  Development of novel TiO2 sol–gel-derived composite and its photocatalytic activities for trichloroethylene oxidation , 2004 .

[6]  J. García,et al.  Resonant excitation of Er ion luminescence in a nanocrystalline silicon matrix , 2004 .

[7]  K. Tennakone,et al.  Construction of a photovoltaic device by deposition of thin films of the conducting polymer polythiocyanogen , 2004 .

[8]  Yongxiang Li,et al.  Hydrogen sensitive GA2O3 Schottky diode sensor based on SiC , 2004 .

[9]  C. Mignotte.  Structural characterization for Er3+-doped oxide materials potentially useful as optical devices , 2004 .

[10]  Wojtek Wlodarski,et al.  Investigation of sol–gel prepared Ga–Zn oxide thin films for oxygen gas sensing , 2003 .

[11]  Wojtek Wlodarski,et al.  Investigation of sol–gel prepared CeO2–TiO2 thin films for oxygen gas sensing , 2003 .

[12]  Z. Nenova,et al.  Investigation of sol–gel derived thin films of titanium dioxide doped with vanadium oxide , 2003 .

[13]  Dazhi Yang,et al.  Sol–gel deposited TiO2 film on NiTi surgical alloy for biocompatibility improvement , 2003 .

[14]  S T Aruna,et al.  COMBUSTION SYNTHESIS: AN UPDATE , 2002 .

[15]  Tatyana Ivanova,et al.  Formation and investigation of sol–gel TiO2–V2O5 system , 2002 .

[16]  Wojtek Wlodarski,et al.  Gas Sensing Properties of P-type Semiconducting Cr-doped TiO2 Thin Films , 2002 .

[17]  F. d’Acapito,et al.  Local order around Er3+ ions in SiO2-TiO2-Al2O3 glassy films studied by EXAFS , 2001 .

[18]  P. Douglas,et al.  An active, robust and transparent nanocrystalline anatase TiO2 thin film — preparation, characterisation and the kinetics of photodegradation of model pollutants , 2001 .

[19]  M. Audier,et al.  The effects of phosphorus on the crystallisation and photoluminescence behaviour of aerosol gel deposited SiO2 TiO2 Er2O3 P2O5 thin films , 2001 .

[20]  Wojtek Wlodarski,et al.  Nanocrystalline V2O5–TiO2 thin-films for oxygen sensing prepared by sol–gel process , 2001 .

[21]  M. Carotta,et al.  Preparation and characterization of nanosized titania sensing film , 2001 .

[22]  G. Sberveglieri,et al.  Semiconductor MoO3–TiO2 thin film gas sensors , 2001 .

[23]  P. Smirniotis,et al.  Surface Characterization of Ga2O3-TiO2 and V2O5/Ga2O3-TiO2 Catalysts , 2001 .

[24]  C. Coutier,et al.  Sol–gel thin film deposition and characterization of a new optically active compound: Er2Ti2O7 , 2001 .

[25]  K. Galatsis,et al.  Microstructural characterization of sol-gel derived Ga/sub 2/O/sub 3/-TiO/sub 2/ thin films for gas sensing , 2000, COMMAD 2000 Proceedings. Conference on Optoelectronic and Microelectronic Materials and Devices.

[26]  Vincenzo Guidi,et al.  Doping of a nanostructured titania thick film: structural and electrical investigations , 2000 .

[27]  Liaoying Zheng,et al.  TiO2−x thin films as oxygen sensor , 2000 .

[28]  K. Kikuta,et al.  Gas sensing properties of platinum dispersed-TiO2 thin film derived from precursor , 2000 .

[29]  S. V. Baran,et al.  Sorption and gas sensitive properties of In2O3 based ceramics doped with Ga2O3 , 1998 .

[30]  J. McGilp,et al.  Erbium luminescence in sol-gel derived oxide glass films , 1998 .

[31]  Claus-Dieter Kohl,et al.  CO-SENSOR FOR DOMESTIC USE BASED ON HIGH TEMPERATURE STABLE GA2O3 THIN FILMS , 1998 .

[32]  Rui M. Almeida,et al.  Active optical properties of Er-containing crystallites in sol gel derived glass films , 1998 .

[33]  Norio Miura,et al.  Zinc-oxide-based semiconductor sensors for detecting acetone and capronaldehyde in the vapour of consommé soup , 1995 .

[34]  R. Tilley,et al.  Phase relations in the pseudobinary system TiO2Ga2O3 , 1977 .

[35]  G. Socrates,et al.  Infrared characteristic group frequencies : tables and charts , 1994 .

[36]  Howard F. McMurdie,et al.  Phase diagrams for ceramists , 1964 .

[37]  D. H. Everett.  An introduction to the study of chemical thermodynamics , 1959 .