Study of Photocatalytic Degradation of Methyl Orange on Different Morphologies of ZnO Catalysts


In this study, several ZnO catalysts were prepared using different zinc sources as precursors. The different catalyst mor- phologies obtained were used to degrade photocatalytically a methyl orange (MO) dye solution, which was used to model wastewater pollution. The precursors, Zn(CH3COO)2, ZnCl2 and Zn(NO3)2, were individually added to a solution containing cetyltrimethylammonium bromide (CTAB) and sodium hydroxide (NaOH) for the hydrothermal synthesis of ZnO. After the hydrothermal reaction, the samples of ZnO were filtered, washed, dried at 110?C and calcined at 550?C, resulting in the formation of the rod-like (designated ZnO(I)), the rice-like (designated ZnO(II)) and the granular-like (designated ZnO(III)) catalysts. The catalysts were characterized by X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM) and their UV-visible diffuse reflectance spectra (UV-Vis DRS). The results indicate that the photocatalytic degradation of the MO solution, after 60 min of UV irradiation, can reach percentages of 40%, 96% and 99% using the catalysts ZnO(I), ZnO(II) and ZnO(III), respectively. The morphology of the ZnO catalyst had an ap- parent effect on the rate of the photocatalytic degradation of MO. The ZnO(II) and ZnO(III) catalysts have higher S/V ratios and a greater content of oxygen vacancies, resulting in different absorbances of ultraviolet light, which leads to different rates of photocatalytic degradation of MO.

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C. Tang, "Study of Photocatalytic Degradation of Methyl Orange on Different Morphologies of ZnO Catalysts," Modern Research in Catalysis, Vol. 2 No. 2, 2013, pp. 19-24. doi: 10.4236/mrc.2013.22003.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] P. T. Anastas, L. B. Bartlett, M. M. Kirchhoff and T. C. Williamson, “The Role of Catalysis in the Design, Development, and Implementation of Green Chemistry,” Catalysis Today, Vol. 55, No. 1-2, 2000, pp. 11-22.
[2] G. Centi and S. Perathoner, “Catalysis and Sustainable (Green) Chemistry,” Catalysis Today, Vol. 77, No. 4, 2003, pp. 287-297.
[3] G. J. Hutchings, “A Golden Future for Green Chemistry,” Catalysis Today, Vol. 122, No. 3-4, 2007, pp. 196-200. doi:10.1016/j.cattod.2007.01.018
[4] L. Wang, X. Yang, X. Zhao,Y. Han, R. Zhang and Y. Yang, “Synthesis and Recycle of ZnO Particles for Degradation of Methyl Orange Aqueous Solution,” Applied Mechanics and Materials, Vol. 121-126, No. 12, 2012, pp. 587-591. doi:10.4028/
[5] S. Chakrabarti and B. K. Dutta, “Photocatalytic Degradation of Model Textile Dyes in Wastewater Using ZnO as Semiconductor Catalyst,” Journal of Hazardous Materials, Vol. B112, No. 3, 2004, pp. 269-278. doi:10.1016/j.jhazmat.2004.05.013
[6] C. Hariharan, “Photocatalytic Degradation of Organic Contaminants in Water by ZnO Nanoparticles: Revisited,” Applied Catalysis A: General, Vol. 304, No. 8, 2006, pp. 55-61. doi:10.1016/j.apcata.2006.02.020
[7] S. Sakthivel, B. Neppolian, M. V. Shankar, B. Arabindoo, M. Palanichamy and V. Murugesan, “Solar Photocatalytic Degradation of Azo Dye: Comparison of Photocatalytic Efficiency of ZnO and TiO2,” Solar Energy Materials and Solar Cells, Vol. 77, No. 1, 2003, pp. 65-82.
[8] S. Anandan, A. Vinu, T. Mori, N. Gokulakrishnan, P. Srinivasu, V. Murugesan and K. Ariga, “Photocatalytic Degradation of 2,4,6-Trichlorophenol Using Lanthanum Doped ZnO in Aqueous Suspension,” Catalysis Communications, Vol. 8, No. 9, 2007, pp. 1377-1382. doi:10.1016/j.catcom.2006.12.001
[9] H. Fan, X. Zhao, J. Yang, X. Shan, L. Yang, Y. Zhang, X. Li and M. Gao, “ZnO-Graphene Composite for Photocatalytic Degradation of Methylene Blue Dye,” Catalysis Communications, Vol. 29, No. 8, 2012, pp. 29-34.
[10] B. Pare, S. B. Jonnalagadda, H. Tomar, P. Singh and V. W. Bhagwat, “ZnO Assisted Photocatalytic Degradation of Acridine Orange in Aqueous Solution Using Visible Irradiation,” Desalination, Vol. 232, No. 1-3, 2008, pp. 80-90. doi:10.1016/j.desal.2008.01.007
[11] R. Y. Hong, J. H. Li, L. L. Chen, D. Q. Liu, H. Z. Li, Y. Zheng and J. Ding, “Synthesis, Surface Modification and Photocatalytic Property of ZnO Nanoparticles,” Powder Technology, Vol. 199, No. 3, 2009, pp. 426-432. doi:10.1016/j.powtec.2008.07.004
[12] S. A. Khayyat, M. S. Akhtar and A. Umar, “ZnO Nanocapsules for Photocatalytic Degradation of Thionine,” Materials Letters, Vol. 81, No. 68, 2012, pp. 239-241. doi:10.1016/j.matlet.2012.04.039
[13] N. Yu, B. Dong, W. W. Yu, B. Hu, Y. Zhang and Yan Cong, “Investigations of ZnO Nanostructures Grown on Patterned Sapphire Using Different Precursors in Aqueous Solutions,” Applied Surface Science, Vol. 258, No. 15, 2012, pp. 5729-5732. doi:10.1016/j.apsusc.2012.02.078
[14] C. Chena, B. Yu, P. Liu, J. F. Liu and L. Wang, “Investigation of Nano-Sized ZnO Particles Fabricated by Various Synthesis Routes,” Journal of Ceramic Processing Research, Vol. 12, No. 4, 2011, pp. 420-425.
[15] C. Chen, J. Liu, P. Liu and B. Yu, “Investigation of Photocatalytic Degradation of Methyl Orange by Using Nano-Sized ZnO Catalysts,” Advances in Chemical Engineering and Science, Vol. 1, No. 1, 2011, pp. 9-14. doi:10.4236/aces.2011.11002
[16] X. Fang, S. Li, X. H. Wang, F. Fang, X. Y. Chu, Z. P. Wei, J. H. Li, X. Y. Chen and F. Wang, “The Growth and Photocatalytic Property of ZnO Nanofibers Synthesized by Atom Layer Deposition Using PVP Nanofibers as Templates,” Applied Surface Science, Vol. 263, No. 4, 2012, pp. 14-17. doi:10.1016/j.apsusc.2012.08.048
[17] F. Z. Sun, X. L. Qiao, F. T. Tan, W. Wang and X. L. Qiu, “Fabrication and Photocatalytic Activities of ZnO Arrays with Different Nanostructures,” Applied Surface Science, Vol. 263, No. 112, 2012, pp. 704-711. doi:10.1016/j.apsusc.2012.09.144
[18] J. B. Zhong, J. Z. Li, Z. H. Xiao, W. Hu, X. B. Zhou, X. and W. Zheng, “Improved Photocatalytic Performance of ZnO Prepared by Sol-Gel Method with the Assistance of CTAB,” Materials Letters, Vol. 91, No. 83, 2013, pp. 301-303.
[19] M. Farbod and E. Jafarpoor, “Fabrication of Different ZnO Nanostructures and Investigation of Morphology Dependence of Their Photocatalytic Properties,” Materials Letters, Vol. 85, No. 15, 2012, pp. 47-49.
[20] S. T. Tan, B. J. Chen, X. W. Sun, W. J. Fan, H. S. Kwok, X. H. Zhang and S. J. Chua, “Blueshift of Optical Band Gap in ZnO Thin Films Grown by Metal-Organic Chemical-Vapor Deposition,” Journal of Applied Physics, Vol. 98, No. 1, 2005, Article ID: 013505. doi:10.1063/1.1940137
[21] J. Z. Kong, A. D. Li, H. F. Zhai, Y. P. Gong, H. Li and D. Wu, “Preparation, Characterization of the Ta-Doped ZnO Nanoparticles and Their Photocatalytic Activity under Visible-Light Illumination,” Journal of Solid State Chemistry, Vol. 192, No. 8, 2009, pp. 2061-2067. doi:10.1016/j.jssc.2009.03.022
[22] T. Sun, J. Qiu and C. Liang, “Controllable Fabrication and Photocatalytic Activity of ZnO Nanobelt Arrays,” Journal of Physical Chemistry C, Vol. 112, No. 3, 2008, pp. 715-721. doi:10.1021/jp710071f
[23] E. S. Jang, J. H. Won, S. J. Hwang and J. H. Choy, “Fine Tuning of the Face Orientation of ZnO Crystals to Optimize Their Photocatalytic Activity,” Advanced Materials, Vol. 18, No. 24, 2006, pp. 3309-3312. doi:10.1002/adma.200601455
[24] J. L. Yang, S. J. An, W. I. Park, G. C. Yi and W. Choi, “Photocatalysis Using ZnO Thin Films and Nanoneedles Grown by Metal-Organic Chemical Vapor Deposition,” Advanced Materials, Vol. 16, No. 18, 2004, pp. 1661-1664. doi:10.1002/adma.200306673
[25] W. W. Wang, Y. J. Zhu and L. X. Yang, “ZnO-SnO2 Hollow Spheres and Hierarchical Nanosheets: Hydrothermal Preparation, Formation Mechanism, and Photocatalytic Properties,” Advanced Functional Materials, Vol. 17, No. 1, 2007, pp. 59-64. doi:10.1002/adfm.200600431
[26] H. Gerischer, “Photoelectrochemical Catalysis of the Oxidation of Organic Molecules by Oxygen on Small Semiconductor Particles with TiO2 as an Example,” Electrochimica Acta, Vol. 38, No. 1, 1993, pp. 3-9.
[27] M. Zhang, T. An, X. Hu, C. Wang, G. Sheng and J. Fu, Preparation and Photocatalytic Properties of a Nanometer ZnO-SnO2 Coupled Oxide,” Applied Catalysis A, Vol. 260, No. 2, 2004, pp. 215-222. doi:10.1016/j.apcata.2003.10.025

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