为了在水相体系制备尺寸均一、形貌可控的锐钛矿型纳米TiO2颗粒,研究了钛源、溶液pH值、反应温度对TiO2晶体结构的影响.通过对样品进行XRD、TEM表征,发现形成锐钛矿型TiO2的最佳实验条件为:硫酸钛作为钛源、硝酸浓度为0.14 mol/L、反应温度60℃.硝酸浓度低、反应温度高有利于锐钛矿型TiO2的形成,反之则利于金红石的形成.通过在锐钛矿形成过程中施加外场作用,即紫外光和超声波,探究外场对其形貌的影响.结果表明:无外场作用时,生成的锐钛矿为纺锤状,尺寸为20～30 nm;施加紫外光4h之后,形状为近球状,尺寸约为10nm;施加超声波之后,形状仍为纺锤状,且尺寸无变化.造成TiO2形貌变化的主要原因是,在成核-长大过程中,紫外光可以抑制[001]晶向的生长速度,且时间越长,这种抑制作用越明显,当作用时间为4h时,[001]晶向的生长得到明显的抑制,使得纳米晶由纺锤状变为近似球形.因此,在TiO2的合成过程中可以通过施加外场作用对其形貌进行调控.
参考文献
| [1] | Fujishima A;Honda K .Electrochemical photolysis of water at a semiconductor electrode[J].NATURE,1972,238(5358):37. |
| [2] | Amy L. Linsebigler;Guangquan Lu;John T. Yates Jr. .Photocatalysis on TiO_2 Surfaces: Principles, Mechanisms, and Selected Results[J].Chemical Reviews,1995(3):735-758. |
| [3] | Campbell M;Sharp D N;Harrison M T et al.Fabrication of photonic crystals for the visible spectrum by holographic lithography[J].NATURE,2000,404(52):53. |
| [4] | Ohko Y;Tatsuma T;Fujii T et al.Multicolour photochromism of TiO2 films loaded with silver nanoparticles[J].Nature Mater,2003,3:29. |
| [5] | Sauvage F;Chen DH;Comte P;Huang FZ;Heiniger LP;Cheng YB;Caruso RA;Graetzel M .Dye-Sensitized Solar Cells Employing a Single Film of Mesoporous TiO2 Beads Achieve Power Conversion Efficiencies Over 10%[J].ACS nano,2010(8):4420-4425. |
| [6] | Pottier A.;Tronc E.;Mazerolles L.;Jolivet JP.;Chaneac C. .Synthesis of brookite TiO2 nanoparticles by thermolysis of TiCl4 in strongly acidic aqueous media[J].Journal of Materials Chemistry: An Interdisciplinary Journal dealing with Synthesis, Structures, Properties and Applications of Materials, Particulary Those Associated with Advanced Technology,2001(4):1116-1121. |
| [7] | Oskam G;Nellore A et al.The growth kinetics of TiO2 nanoparticles from titanium(Ⅳ) alkoxide at high water/titanium ratio[J].Journal of Physical Chemistry B,2003,107(08):1734. |
| [8] | Zhang Q;Gao L .Preparation of oxide nanocrystals with tunable morphologies by the moderate hydrothermal method:Insights from rutile TiO2[J].LANGMUIR,2003,19(03):967. |
| [9] | Kim KD;Kim SH;Kim HT .Applying the Taguchi method to the optimization for the synthesis of TiO2 nanoparticles by hydrolysis of TEOT in micelles[J].Colloids and Surfaces, A. Physicochemical and Engineering Aspects,2005(1/3):99-105. |
| [10] | Song R Q;C(o)lfen H .Additive controlled crystallization[J].Cryst Eng Comm,2011,13(05):1249. |
| [11] | Tadao Sugimoto;Xingping Zhou;Atsushi Muramatsu .Synthesis of uniform anatase TiO_2 nanoparticles by gel-sol method 3. Formation process and size control[J].Journal of Colloid and Interface Science,2003(1):43-52. |
| [12] | Nakajima A;Hayashi N;Taniguchi Y;Kameshima Y;Okada K .Effect of vacuum ultraviolet light illumination on the crystallization of sol-gel-derived titanium dioxide precursor films[J].Surface & Coatings Technology,2005(1):112-116. |
| [13] | Yu J C;Yu J;Ho W et al.Preparation of highly photocatalytic active nano-sized TiO2 particles via ultrasonic irradiation[J].Chemistry Communications,2001,19:1942. |
| [14] | Lazzeri M.;Selloni A.;Vittadini A. .Structure and energetics of stoichiometric TiO2 anatase surfaces - art. no. 155409[J].Physical Review.B.Condensed Matter,2001(15):155409-1-155409-9. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%