[雙語(yǔ)翻譯]--外文翻譯--熱處理對(duì)納米板鈦礦二氧化鈦薄膜的溶膠-凝膠法生產(chǎn)粒度的影響（英文）

1、Influence of heat treatment on the particle size of nanobrookite TiO2 thin films produced by sol–gel methodÜmit Özlem Akkaya Ar?er a,b,?, Fatma Zehra Tepehanba Department of Physics, Mimar Sinan Fine Arts Unive

2、rsity, Besiktas, Istanbul 34349, Turkey b Department of Physics, Istanbul Technical University, Maslak, Istanbul, 34469, Turkeya b s t r a c t a r t i c l e i n f oArticle history:Received 8 March 2011Accepted in revised

3、 form 20 June 2011Available online 30 June 2011Keywords:TiO2 NanobrookiteTemperatureParticle sizeSol–gelPure nanobrookite titania (TiO2) thin films were deposited on glass substrates by the spin-coating methodusing titan

4、ium butoxide and acetic acid. The particle sizes of TiO2 films were controlled by heat treatmenttemperatures. The activation energy for particle growth was calculated as 23.1 kJ/mol. The structural andoptical properties

5、of the nanobrookite TiO2 thin films were characterized by X-ray diffraction (XRD), atomicforce microscopy (AFM), scanning electron microscopy (SEM), ultraviolet–visible absorption spectroscopy(UV–vis), and Fourier transf

6、orm infrared spectroscopy (FTIR).© 2011 Elsevier B.V. All rights reserved.1. IntroductionTiO2 (titania) is a very important transition metal oxide because ofits use in various applications, including optoelectronic

7、applications,photocatalytic activities, solar cells, electrochromic applications,hydrogen storage and gas sensors [1–4]. The brookite phase, whichis one of three phases of TiO2, is difficult to produce in its pure form[5

8、,6].Several methods have been used to prepare brookite TiO2 structures, including the hydrothermal method, sol–gel deposition,chemical vapor deposition (CVD), and pulsed laser deposition (PLD)[6,7].Many different TiO2 st

9、ructures are produced in the brookite phase,including powder, films, nanorods and nanoflowers [6–9]. The brookitephase of nanocrystalline TiO2 is synthesized by the thermohydrolysis ofTiCl4 (tetrachloride), titanium tetr

10、aisopropoxide and butoxide in HCl orNaCl solutions [10–13]. The brookite phase of nanostructured TiO2 isusually used for solar cells and photocatalytic applications [14–21].Particle size, which can be controlled with the

11、 sol–gel coating process, isa very important parameter for nanosystems. Nanostructured TiO2 isprepared by the sol–gel method under different preparation conditions,such asheat treatments. The effects of heat treatmenton

12、the particle sizeof nanostructured TiO2 have been studied in detail. The particle size ofnanostructured TiO2, which can be controlled by the heat treatmenttemperature during the sol–gel deposition process, has been measu

13、redusing XRD. The particle sizes of anatase-phase nano-TiO2 powdersproduced with temperatures between 400 and 800 °C have been foundto be in the range of 6.2 to 21.1 nm [22]. The particle sizes of nanocrystalTiO2 fi

14、lms produced with temperatures between 350 and 550 °C havebeen found to be in the range of 12.4 to 20.3 nm, and temperaturesbetween 350 and 500 °C have produced anatase-phase nanocrystal TiO2 particles in the 7

15、 to 30 nm range [23,24]. Published results indicate thatthe particle size of nanostructured TiO2 increases with an increase in theheat treatment temperature because of the increasing crystallization[22,25]. Thermal treat

16、ment can improve the crystallinity of theamorphous compounds.The anatase and brookite phases, which are transformed into therutile phase when they are heated, are metastable, whereas the rutilephase is stable. The brooki

17、te phase is difficult to produce purely. As aresult, the activation energy of the pure brookite phase has beendetermined to be much less than the activation energy of the anataseand rutile phases.The activation energy fo

18、r anatase-phase TiO2 film deposition hasbeen calculated to be approximately 77.9 kJ/mol [26].The activation energy for crystallite growth of nanostructuredTiO2–CeO2 mixed oxide powders, which are produced in the anatasea

19、nd rutile phases by the sol–gel process, was calculated to be in therange of 1.92–8.79 kJ/mol [27]. The activation energy for the brookite–rutile transition has been calculated to be 143.4 kJ/mol with theJohnson–Mehl–Avr

20、ami–Kolmogorov (JMAK) model and to be492.13 kJ/mol with the JMAK model [28,29]. The purpose of ourresearch is to determine the value of the activation energy for particlegrowth of the pure nanobrookite TiO2 thin films. W

21、e synthesized purebrookite-phase nanostructured TiO2 films using titanium butoxide,ethanol and acetic acid. The activation energy for particle growth inthe pure nanobrookite TiO2 films was determined using the ArrheniusS

22、urface 2.65; 3.11; and 5.60 nm for the 400, 450, 500,and 550 °C heat treatment temperature values. The roughnessincreased with the increasing heat treatment temperature. It wasfound that the film heated at 550 

23、6;C possessed the roughest surfacestructure because it had the biggest particle size, while the film heatedat 400 °C possessed the smoothest surface structure because it had theFig. 3. SEM images of nanobrookite TiO

24、2 films for different heat treatment temperature: (a) 450, (b) 500, (c) 550 °C.Fig. 4. AFM images of nanobrookite TiO2 films for different heat treatment temperature: (a) 450, (b) 500, (c) 550 °C.39 Ü.