Effect of hydrolysis rate on the properties of TiO2-CNT nanocomposite powder prepared by sol-gel method

Document Type: Research Paper


School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran


In this study, TiO2-10%wt. carbon nanotube (CNT) nanocomposite powders were synthesized by sol-gel method at various hydrolysis rate affected by different reaction agents of acetyl acetone and benzyl alcohol. Crystallization of TiO2 was then achieved through calcination at 400 °C. The properties of nanocomposite powder investigated by scanning electron microscopy, X-ray diffraction and diffuse reflectance spectroscopy. The results showed that, the crystalline TiO2 with anatase structure was produced after calcination. The crystallite size of TiO2 depended on the hydrolysis rate which was increased from 25 nm at higher hydrolysis rate by benzyl alcohol to 55 nm at slower hydrolysis rate by acetyl acetone. Before calcination, the results have shown that the slower hydrolysis rate yields relatively large particles with a plate like morphology in contrast to the presence of small particles with significant agglomeration at higher hydrolysis rate by benzyl alcohol. After calcination, high hydrolysis reaction through the use of benzyl alcohol offers easy access to the TiO2-10%wt. CNT nanocomposite with well controlled coating and desirable interactions between TiO2 and the CNTs. The thickness of TiO2 coating on CNTs in this way was 80 nm. Also, TiO2 particle size depended on the hydrolysis rate, decreased from 1 μm in presence of acetyl acetone to 150 nm in presence of benzyl alcohol. The band gap energy at higher hydrolysis rate by benzyl alcohol was 2.95 eV.


1. Chen X, Mao SS. Titanium Dioxide Nanomaterials:  Synthesis, Properties, Modifications, and Applications. Chemical Reviews. 2007;107(7):2891-959.

2. Sellappan R. Mechanisms of enhanced activity of model TiO2/carbon and TiO2/metal nanocomposite photocatalysts. Chalmers University of Technology; 2013.

3.  Carp O. Photoinduced reactivity of titanium dioxide. Progress in Solid State Chemistry. 2004;32(1-2):33-177.

4. Woan K, Pyrgiotakis G, Sigmund W. Photocatalytic Carbon-Nanotube-TiO2Composites. Advanced Materials. 2009;21(21):2233-9.

5. Cong Y, Li X, Qin Y, Dong Z, Yuan G, Cui Z, et al. Carbon-doped TiO2 coating on multiwalled carbon nanotubes with higher visible light photocatalytic activity. Applied Catalysis B: Environmental. 2011;107(1-2):128-34.

6. Di J, Li S, Zhao Z, Huang Y, Jia Y, Zheng H. Biomimetic CNT@TiO2 composite with enhanced photocatalytic properties. Chemical Engineering Journal. 2015;281:60-8.

7. Yao Y, Li G, Ciston S, Lueptow RM, Gray KA. Photoreactive TiO2/Carbon Nanotube Composites: Synthesis and Reactivity. Environmental Science & Technology. 2008;42(13):4952-7.

8. Eder D, Windle AH. Morphology control of CNT-TiO2 hybrid materials and rutile nanotubes. Journal of Materials Chemistry. 2008;18(17):2036.

9.  Serp P, Figueiredo JL, editors. Carbon materials for catalysis. John Wiley & Sons; 2009 Feb 4.

10. Robel I, Bunker BA, Kamat PV. Single-Walled Carbon Nanotube-CdS Nanocomposites as Light-Harvesting Assemblies: Photoinduced Charge-Transfer Interactions. Advanced Materials. 2005;17(20):2458-63.

11. Kamat PV. Harvesting photons with carbon nanotubes. Nano Today. 2006;1(4):20-7.

12. Kongkanand A, Kamat PV. Electron Storage in Single Wall Carbon Nanotubes. Fermi Level Equilibration in Semiconductor–SWCNT Suspensions. ACS Nano. 2007;1(1):13-21.

13. Xu Y-J, Zhuang Y, Fu X. New Insight for Enhanced Photocatalytic Activity of TiO2 by Doping Carbon Nanotubes: A Case Study on Degradation of Benzene and Methyl Orange. The Journal of Physical Chemistry C. 2010;114(6):2669-76.

14. Ząbek P, Eberl J, Kisch H. On the origin of visible light activity in carbon-modified titania. Photochemical & Photobiological Sciences. 2009;8(2):264.

15. Yu H, Quan X, Chen S, Zhao H, Zhang Y. TiO2–carbon nanotube heterojunction arrays with a controllable thickness of TiO2 layer and their first application in photocatalysis. Journal of Photochemistry and Photobiology A: Chemistry. 2008;200(2-3):301-6.

16. Yen C-Y, Lin Y-F, Hung C-H, Tseng Y-H, Ma C-CM, Chang M-C, et al. The effects of synthesis procedures on the morphology and photocatalytic activity of multi-walled carbon nanotubes/TiO2nanocomposites. Nanotechnology. 2008;19(4):045604.

17. Eder D, Windle AH. Carbon–Inorganic Hybrid Materials: The Carbon-Nanotube/TiO2 Interface. Advanced Materials. 2008;20(9):1787-93.

18. Akhavan O, Azimirad R, Safa S, Larijani MM. Visible light photo-induced antibacterial activity of CNT–doped TiO2 thin films with various CNT contents. Journal of Materials Chemistry. 2010;20(35):7386.

19. Brinker CJ, Scherer GW. Sol-gel science: the physics and chemistry of sol-gel processing. Academic press; 2013 Oct 22.

20. Mamunya Y, Iurzhenko M. Advances in progressive thermoplastic and thermosetting polymers, perspectives and applications. CCUE NASU in IMC NASU; 2012.

21.  Williamson GK, Hall WH. X-ray line broadening from filed aluminium and wolfram. Acta Metallurgica. 1953;1(1):22-31.

22. Xie Y, Qian H, Zhong Y, Guo H, Hu Y. Facile Low-Temperature Synthesis of Carbon Nanotube/ Nanohybrids with Enhanced Visible-Light-Driven Photocatalytic Activity. International Journal of Photoenergy. 2012;2012:1-6.

23. Wang W, Serp P, Kalck P, Faria JL. Visible light photodegradation of phenol on MWNT-TiO2 composite catalysts prepared by a modified sol–gel method. Journal of Molecular Catalysis A: Chemical. 2005;235(1-2):194-9.

24. Montero-Ocampo C, Garcia JV, Estrada EA. Comparison of TiO2 and TiO2-CNT as cathode catalyst supports for ORR. Int. J. Electrochem. Sci. 2013 Dec 1;8:12780-800.

25. Zhou W, Zhou Y, Tang S. Formation of TiO2 nano-fiber doped with Gd3+ and its photocatalytic activity. Materials Letters. 2005;59(24-25):3115-8.

26. Sinkó K. Influence of Chemical Conditions on the Nanoporous Structure of Silicate Aerogels. Materials. 2010;3(1):704-40.

27. Niederberger M. Nonaqueous Sol–Gel Routes to Metal Oxide Nanoparticles. Accounts of Chemical Research. 2007;40(9):793-800.

28. Kumar Y, Herrera-Zaldivar M, Olive-Méndez S, Singh F, Mathew X, Agarwal V. Modification of optical and electrical properties of zinc oxide-coated porous silicon nanostructures induced by swift heavy ion. Nanoscale Research Letters. 2012;7(1):366.