SYNTHESIS of Ag-DOPED ZnO NANOFIBERS USING ELECTROSPINNING METHOD and THEIR PHOTOCATALYTIC ACTIVITIES

Silver (Ag) doped zinc oxide (ZnO) nanofibers with 1 at.% and 3 at.% Ag content were prepared using the electrospinning technique and their structural, morphological and photocatalytic properties were investigated. Pure ZnO nanofibers were also prepared with the same procedure for structure and property related comparison purposes. The photocatalytic activity of the Ag doped ZnO nanofibers were determined as a function of Ag content by exploring the degradation behavior of methylene blue under UV light irradiation. It was found that photocatalytic ability of fibers was improved with Ag addition and higher Ag incorporation resulted higher methylene blue degradation rate. For pure ZnO fibers, the degraded amount of dye was 52% of its initial amount after 270 min of UV irradiation time. For the same irridation time, 60% and 67% decomposition ratios of the dye molecules were achieved with the fibers containing 1 at.% Ag and 3 at.% Ag, respectively. The origin of the improvement of photocatalytic activity in Ag doped ZnO nanofibers was attributed to the substitutional incorporation of Ag ions into Zn sites within the ZnO crystal. The substitutional incorporation has been proved with the positional shift of the XRD diffraction lines.

Elektro Eğirme Yöntemi Kullanılarak Ag Aşılanmış ZnO Nano Fiberlerin Sentezi ve Foto Katalitik Aktivitelerinin İncelenmesi

%1 ve %3 gümüş (Ag) içeren Ag aşılanmış çinko oksit (ZnO) nano fiberler elektro eğirme yöntemi kullanılarak hazırlanmış ve yapısal, şekilsel ve foto katalitik özellikleri incelenmiştir. Saf ZnO nano fiberler de yapı ve özelliklerin karşılaştırılması amacı ile aynı yöntemle sentezlenmişlerdir, Ag aşılanmış ZnO nano fiberlerin foto katalitik özellikleri UV ışığı altında metilen mavisini bozma eğiliminin Ag miktarına bağlı olarak değişiminin bir fonksiyonu olarak belirlenmiştir. Ag aşılama ile fiberlerin foto katalitik aktivitelerinin geliştiği ve yüksek miktarda Ag miktarının eklenmesi ile metilen mavisinin bozunum oranının daha iyi olduğu bulunmuştur. Saf ZnO fiberler ile 270 dakikalık UV ışımasından sonra boyanın bozunum miktarının %52 oranında olduğu tespit edilmiştir. Aynı ışıma suresinde %1 Ag içeren fiberlerde boya moleküllerinin bozunum oranı %60 iken, %3 Ag içeren fiberlerde bu oran %77’dir. Ag aşılama ile ZnO fiberlerin foto katalitik aktivitelerinde gözlemlenen iyileşme ZnO kristal yapısında Zn bölgeleri içine Ag iyonlarının yer alan atom olarak geçmesi ile açıklanabilir. Yer alan atom pozisyonunda yerleşme XRD piklerinin pozisyonlarında meydana gelen kayma ile doğrulanmıştır.

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Chen, S., Zhao, W., Liu, W., Zhang, S., 2008, "Preparation, Characterization and Activity Evaluation of p–n Junction Photocatalyst p-ZnO/n-TiO 2", Applied Surface Science, Vol. 255, No. 5, pp. 2478- 2484.

Costi, R., Saunders, A. E., Elmalem, E., Salant A., Banin, U., 2008, "Visible Light-induced Charge Retention and Photocatalysis with Hybrid CdSe− Au Nanodumbbells", Nano Letters, Vol. 8, No. 2, pp. 637-641.

Hsu, M.-H., Chang, C.-J., 2014, "Ag-doped ZnO Nanorods Coated Metal Wire Meshes as Hierarchical Photocatalysts with High Visible-Light Driven Photoactivity and Photostability", Journal of Hazardous Materials, Vol. 278, No. 1, pp. 444-453.

Kolodziejczak-Radzimska, A., Jesionowski, T., 2014, "Zinc Oxide-From Synthesis to Application: A Review", Materials, Vol. 7, No. 4, pp. 2833-2881.

Kumar, R., Rana, D., Umar, A., Sharma, P., Chauhan, S., Chauhan, M. S., 2015, "Ag-doped ZnO Nanoellipsoids: Potential Scaffold for Photocatalytic and Sensing Applications", Talanta, Vol. 137, No. 1, pp. 204-213.

Lee, K., M., Lai, C. W., Ngai, K. S., Juan, J. C., 2016, "Recent Developments of Zinc Oxide based Photocatalyst in Water Treatment Technology: a Review", Water Research, Vol. 88, No. 1, pp. 428-448.

Li, P., Wei Z., Wu, T., Peng, Q., Li, Y., 2011, "Au−ZnO Hybrid Nanopyramids and Their Photocatalytic Properties", Journal of the American Chemical Society, Vol. 133, No. 15, pp. 5660-5663.

Liqiang, J., Baiqi, W., Baifu, X., Shudan, L., Keying, S., Weimin, C., Honggang, F., 2004, "Investigations on the Surface Modification of ZnO Nanoparticle Photocatalyst by Depositing Pd", Journal of Solid State Chemistry, Vol. 177, No. 11, pp. 4221-4227.

Litter, M. I., 1999, "Heterogeneous Photocatalysis: Transition Metal Ions in Photocatalytic Systems", Applied Catalysis B: Environmental, Vol. 23, No. 2, pp. 89-114.

Liu, B., Nakata, K., Zhao, X., Ochiai, T., Murakami, T., Fujishima, A., 2011, "Theoretical Kinetic Analysis of Heterogeneous Photocatalysis: the Effects of Surface Trapping and Bulk Recombination Through Defects", The Journal of Physical Chemistry C, Vol. 115, No. 32, pp. 16037-16042.

O'Neil, M., Marohn, J., McLendon, G., 1990, "Dynamics of Electron-Hole Pair Recombination in Semiconductor Clusters", The Journal of Physical Chemistry, Vol. 94, No. 10, pp. 4356-4363.

Patil, S. S., Mali, M. G., Tamboli, M. S., Patil, D. R., Kulkarni, M. V., Yoon, H., Kim, H., Al-Deyab, S. S., Yoon, S. S., Kolekar, S. S., 2016, "Green Approach for Hierarchical Nanostructured Ag-ZnO and Their Photocatalytic Performance under Sunlight", Catalysis Today, Vol. 260, No. 1, pp. 126- 134.

Seery, M. K., George, R., Floris, P., Pillai, S. C., 2007, "Silver Doped Titanium Dioxide Nanomaterials for Enhanced Visible Light Photocatalysis", Journal of Photochemistry and Photobiology A: Chemistry, Vol. 189, No. 2-3, pp. 258-263.

Serpone, N., Pelizzetti, E., 1989, Photocatalysis: fundamentals and applications Sharma, H. D., Lewis, S. P., 1994, Waste Containment Systems, Waste Stabilization, and Landfills: Design and Evaluation, John Wiley & Sons.

Subhan, M. A., Awal, M., Ahmed, T., Younus, M., 2014, "Photocatalytic and Antibacterial Activities of Ag/ZnO Nanocomposities Fabricated by Co-Precipitation Method", Acta Metallurgica Sinica (English Letters), Vol. 27, No. 2, pp. 223-232.

Wang, L., Chang, L., Zhao, B., Yuan, Z., Shao, G., Zheng, W., 2008, "Systematic Investigation on Morphologies, Forming Mechanism, Photocatalytic and Photoluminescent Properties of ZnO Nanostructures Constructed in Ionic Liquids", Inorganic Chemistry, Vol. 47, No. 5, pp. 1443- 1452.

Wang, R., Xin, J. H., Yang, Y., Liu, H., Xu, L., Hu, J., 2004, "The Characteristics and Photocatalytic Activities of Silver Doped ZnO Nanocrystallites", Applied Surface Science, Vol. 227, No. 1, pp. 312-317.

Wang, X., Song, C., Geng, K., Zeng, F., Pan, F., 2006, "Luminescence and Raman Scattering Properties of Ag-doped ZnO films", Journal of Physics D: Applied Physics, Vol. 39, No. 23, pp. 4992.

Wang, Y., Li, X., Wang, N., Quan, X., Chen, Y., 2008, "Controllable Synthesis of ZnO Nanoflowers and Their Morphology-Dependent Photocatalytic activities", Separation and Purification Technology, Vol. 62, No. 3, pp. 727-732.

Wu, J.-J., Tseng, C.-H., 2006, "Photocatalytic Properties of nc-Au/ZnO Nanorod Composites", Applied Catalysis B: Environmental, Vol. 66, No. 1-2, pp. 51-57.

Yan, H., Yang, J., Ma, G., Wu, G., Zong, X., Lei, Z., Shi, J., Li, C., 2009, "Visible-light-driven Hydrogen Production with Extremely High Quantum Efficiency on Pt–PdS/CdS Photocatalyst", Journal of Catalysis, Vol. 266, No. 2, pp. 165-168.

Yıldırım, O.A., Unalan, H. E., Durucan, C., 2013, "Highly Efficient Room Temperature Synthesis of Silver‐Doped Zinc Oxide (ZnO: Ag) Nanoparticles: Structural, Optical, and Photocatalytic Properties", Journal of the American Ceramic Society, Vol. 96, No. 3, pp. 766-773.