Investigation of Structural and Photocatalytic Properties of ZnO Thin Films

Ahmet Çetin; Mehmet Şimşir; Ebru Senadim Tuzemen; Ali Özer

doi:10.17776/csj.1818153

Investigation of Structural and Photocatalytic Properties of ZnO Thin Films

Abstract

This study focuses on the fabrication of immobilized and stable pure ZnO thin films via RF magnetron sputtering to eliminate the drawbacks of powder-based photocatalysts, such as catalyst recovery, filtration difficulties, and secondary pollution risks. While the photocatalytic potential of ZnO is well established, research investigating the structural origins of performance enhancement in undoped ZnO thin films achieved through physical vapor deposition (PVD) parameters and post-deposition annealing remains limited. In this context, the contribution of this work lies in the quantitative demonstration of the enhancement in photocatalytic performance induced by annealing at 400 °C in additive-free ZnO thin films. As-deposited and 400 °C annealed ZnO thin films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy-dispersive X-ray spectroscopy (EDX). XRD analysis confirmed a hexagonal wurtzite structure for both films, while post-deposition annealing improved crystalline quality and increased the average crystallite size from 53.3 nm to 57.2 nm. AFM measurements revealed an increase in surface roughness from 1.252 nm to 12.14 nm after annealing. Photocatalytic degradation experiments of methylene blue (MB) were conducted under UV-A irradiation, and concentration changes were monitored by UV–Vis spectroscopy. The as-deposited ZnO thin films exhibited only 11% degradation efficiency after 8 hours, whereas the films annealed at 400 °C achieved 68% degradation after 11 hours, corresponding to a sevenfold enhancement in photocatalytic performance. These results demonstrate that post-deposition annealing is an effective strategy for optimizing the photocatalytic activity of pure ZnO thin films under low-energy UV-A light.

Keywords

Project Number

M-2021-806

Thanks

This work is supported by the Scientific Research Project Fund of Sivas Cumhuriyet University/Turkey under the project number M-2021-806.

References

[1] Shannon, M. A., Bohn, P. W., Elimelech, M., Georgiadis, J. G., Mariñas, B. J., & Mayes, A. M. (2008). Science and technology for water purification in the coming decades. Nature, 452(7185), 301–310. https://doi.org/10.1038/nature06599
[2] Homem, V., & Santos, L. (2011). Degradation and removal methods of antibiotics from aqueous matrices – a review. Journal of Environmental Management, 92(10), 2304–2347. https://doi.org/10.1016/j.jenvman.2011.05.023
[3] Kestioğlu, K., Yonar, T., & Azbar, N. (2005). Feasibility of physico-chemical treatment and advanced oxidation processes (AOPs) as a means of pretreatment of olive mill effluent (OME). Process Biochemistry, 40(7), 2409–2416. https://doi.org/10.1016/j.procbio.2004.09.005
[4] Jang, Y. J., Simer, C., & Ohm, T. (2006). Comparison of zinc oxide nanoparticles and its nano-crystalline particles on the photocatalytic degradation of methylene blue. Materials Research Bulletin, 41(1), 67–77. https://doi.org/10.1016/j.materresbull.2005.07.038
[5] Li, S., Ma, Z., Zhang, J., Wu, Y., & Gong, Y. (2008). A comparative study of photocatalytic degradation of phenol of TiO₂ and ZnO in the presence of manganese dioxides. Catalysis Today, 139(1–2), 109–112. https://doi.org/10.1016/j.cattod.2008.08.016
[6] Kaya, D., Akyol, M., Tüzemen, E. Ş., & Ekicibil, A. (2022). Magnetic and optical properties of ZnO/Ni/ZnO multilayer film on Si (100) and sapphire substrates. Optik, 266, 169595. https://doi.org/10.1016/j.ijleo.2022.169595
[7] Özgür, Ü., Alivov, Y. I., Liu, C., Teke, A., Reshchikov, M. A., Doğan, S., Avrutin, V., Cho, S. J., & Morkoç, H. (2005). A comprehensive review of ZnO materials and devices. Journal of Applied Physics, 98(4), 041301. https://doi.org/10.1063/1.1992666
[8] Schmidt-Mende, L., & MacManus-Driscoll, J. L. (2007). ZnO nanostructures, defects and devices. Materials Today, 10(5), 40–48. https://doi.org/10.1016/S1369-7021(07)70078-0

[9] Sener, E., Bayram, O., Hasar, U. C., & Simsek, O. (2021). Structural and optical properties of RF-sputtered ZnO thin films: Annealing effect. Physica B: Condensed Matter, 605, 412421. https://doi.org/10.1016/j.physb.2020.412421
[10] Lv, J., Gong, W., Huang, K., Zhu, J., Meng, F., Song, X., & Sun, Z. (2011). Effect of annealing temperature on photocatalytic activity of ZnO thin films prepared by sol–gel method. Superlattices and Microstructures, 50(2), 98–106. https://doi.org/10.1016/j.spmi.2011.05.003
[11] Rao, T. P., Kumar, M. C. S., Safarulla, A., Ganesan, V., Barman, S. R., & Sanjeeviraja, C. (2010). Physical properties of ZnO thin films deposited at various substrate temperatures using spray pyrolysis. Physica B: Condensed Matter, 405(9), 2226–2231. https://doi.org/10.1016/j.physb.2010.02.016
[12] Purica, M., Budianu, E., Rusu, E., Danila, M., & Gavrila, R. (2002). Optical and structural investigation of ZnO thin films prepared by chemical vapor deposition (CVD). Thin Solid Films, 403, 485–488. https://doi.org/10.1016/S0040-6090(01)01544-9
[13] Babić, D. J., Peter, R., Perčić, M., Salamon, K., Vengust, D., Radošević, T., Podlogar, M., & Omerzu, A. (2025). Photocatalytic properties of thin ZnO films synthesised with plasma-enhanced atomic layer deposition at room temperature. Vacuum, 231, 114504. https://doi.org/10.1016/j.vacuum.2024.114504
[14] Mandal, S., Singha, R. K., Dhar, A., & Ray, S. K. (2008). Optical and structural characteristics of ZnO thin films grown by RF magnetron sputtering. Materials Research Bulletin, 43(2), 244–250. https://doi.org/10.1016/j.materresbull.2007.02.043
[15] Lubitz, M., Medina, P. A., Antic, A., & Rosin, J. T. (2014). Cost-effective systems for atomic layer deposition. Journal of Chemical Education, 91(7), 1022–1027. https://doi.org/10.1021/ed400508v
[16] Tüzemen, E. Ş. (2025). Enhancement of photocatalytic performance of Ga₂O₃ films with different thicknesses under UVC light. Catalysis Letters, 155(6), 194. https://doi.org/10.1007/s10562-024-04664-9
[17] Abdallah, B., Zetoun, W., & Tello, A. (2024). Deposition of ZnO thin films with different powers using RF magnetron sputtering method: Structural, electrical and optical study. Heliyon, 10(6), e27606. https://doi.org/10.1016/j.heliyon.2024.e27606
[18] Al Rafi, J., Kanda, Y., Honda, M., & Ichikawa, Y. (2024). Annealing effects of ZnO thin film on photocatalytic performances of graphene composites. C, 10(1), 4. https://doi.org/10.3390/c10010004
[19] Sakthivel, R., Anandh, B., Kannusamy, R., Tamilselvan, K., & Geetha, A. (2017). Effect of post annealing on antibacterial activity of ZnO thin films prepared by modified SILAR technique. Oriental Journal of Chemistry, 33(1), 355–362. https://doi.org/10.13005/ojc/330142
[20] Khalfallah, B., Riahi, I., & Chaabouni, F. (2021). Effect of Cu doping on the structural, optical and electrical properties of ZnO thin films grown by RF magnetron sputtering: Application to solar photocatalysis. Optical and Quantum Electronics, 53(5), 238. https://doi.org/10.1007/s11082-021-02857-w
[21] Abdel-Galil, A., Hussien, M. S. A., & Balboul, M. R. (2022). Optimal thickness and annealing temperature for enhancement of structural, optical and photocatalytic properties of ZnO thin films. Journal of the Australian Ceramic Society, 58(5), 1667–1683. https://doi.org/10.1007/s41779-022-00789-9
[22] Aydınoğlu, H. S., & Tüzemen, E. Ş. (2025). Effect of substrate temperature on the photocatalytic degradation efficiency of methylene blue using TiO₂ thin films. Reaction Kinetics, Mechanisms and Catalysis, 1–18. https://doi.org/10.1007/s11144-024-02758-1
[23] Chehhat, K., Chehhat, A. E., Kara, R., Yacoub, A., Salhi, F., Mecif, A., Noua, A. E. (2025). Study of effect of high annealing temperature on the photocatalytic activity of ZnO thin films prepared by dip-coating method. Transition Metal Chemistry, 50(3), 335–343. https://doi.org/10.1007/s11243-024-00624-0
[24] Moustaghfir, A., Tomasella, E., Amor, S. B., Jacquet, M., Cellier, J., & Sauvage, T. (2003). Structural and optical studies of ZnO thin films deposited by RF magnetron sputtering: Influence of annealing. Surface and Coatings Technology, 174, 193–196. https://doi.org/10.1016/S0257-8972(03)00412-2
[25] Arif, M., Sanger, A., Vilarinho, P. M., & Singh, A. (2018). Effect of annealing temperature on structural and optical properties of sol–gel-derived ZnO thin films. Journal of Electronic Materials, 47(7), 3678–3684. https://doi.org/10.1007/s11664-018-6214-5
[26] Zhang, X. L., Hui, K. N., Hui, K. S., & Singh, J. (2013). Structural and optical characterization of high-quality ZnO thin films deposited by reactive RF magnetron sputtering. Materials Research Bulletin, 48(3), 1093–1098. https://doi.org/10.1016/j.materresbull.2012.12.016
[27] Kaushik, V., Bhardwaj, K., Kumar, D., Kumar, M., & Sharma, S. K. (2024). Effect of various processing parameters on the properties of ZnO thin films. Hybrid Advances, 7, 100295. https://doi.org/10.1016/j.hybadv.2024.100295
[28] Liu, Z., Guo, Y., Li, S., Chen, Y., Deng, K., Liu, H., Guo, S., Dong, X., & Cao, H. (2025). Effects of sputtering process and annealing on the microstructure, crystallization orientation and piezoelectric properties of ZnO films. Next Materials, 6, 100429. https://doi.org/10.1016/j.nxmate.2024.100429
[29] Abraham, P., Shaji, S., Avellaneda, D. A., Aguilar-Martinez, J. A., & Krishnan, B. (2023). (002) oriented ZnO and ZnO:S thin films by direct ultrasonic spray pyrolysis: A comparative analysis of structure, morphology and physical properties. Materials Today Communications, 35, 105909. https://doi.org/10.1016/j.mtcomm.2023.105909
[30] Muthusamy, S., Bharatan, S., Sivaprakasam, S., & Mohanam, R. (2024). Effect of deposition temperature on Zn interstitials and oxygen vacancies in RF-sputtered ZnO thin films and thin film-transistors. Materials, 17(21), 5153. https://doi.org/10.3390/ma17215153
[31] Zhang, Q., Xu, M., You, B., Zhang, Q., Yuan, H., & Ostrikov, K. (2018). Oxygen vacancy-mediated ZnO nanoparticle photocatalyst for degradation of methylene blue. Applied Sciences, 8(3), 353. https://doi.org/10.3390/app8030353
[32] Fonné, J., Burov, E., Gouillart, E., Grachev, S., Montigaud, H., & Vandembroucq, D. (2019). Interdiffusion between silica thin films and soda–lime glass substrate during annealing at high temperature. Journal of the American Ceramic Society, 102(6), 3341–3353. https://doi.org/10.1111/jace.16223
[33] Shaban, M., Zayed, M., & Hamdy, H. (2017). Nanostructured ZnO thin films for self-cleaning applications. RSC Advances, 7(2), 617–631. https://doi.org/10.1039/C6RA24788A
[34] Arulraj, A. (2025). Enhanced photoconductive response of ZnO thin films with the impact of annealing temperatures on structural and optical properties. Scientific Reports, 15(1), 1–10. https://doi.org/10.1038/s41598-024-81234-5
[35] Hao, L., Huang, H., Zhang, Y., & Ma, T. (2021). Oxygen-vacant semiconductor photocatalysts. Advanced Functional Materials, 31(25), 2100919. https://doi.org/10.1002/adfm.202100919
[36] Liang, P., Yang, W., Peng, H., & Zhao, S. (2024). Efficient degradation of methylene blue in industrial wastewater and high cycling stability of nano ZnO. Molecules, 29(23), 5584. https://doi.org/10.3390/molecules29235584
[37] Suppaso, C., Pongkan, N., Intachai, S., Rattanawongsa, W., Baoulan, A., Yamauchi, Y., Asakura, Y., & Khaorapapong, N. (2025). Enhancement of photocatalytic efficiency of copper oxide/zinc oxide–montmorillonite photocatalyst under visible light irradiation. Science and Technology of Advanced Materials, 26(1), 2469484. https://doi.org/10.1080/14686996.2024.2469484
[38] Kulis-Kapuscinska, A., Kwoka, M., Borysiewicz, M. A., Wojciechowski, T., Licciardello, N., Sgarzi, M., Cuniberti, G. (2023). Photocatalytic degradation of methylene blue at nanostructured ZnO thin films. Nanotechnology, 34(15), 155702. https://doi.org/10.1088/1361-6528/acb470
[39] Alfaro Cruz, M. R., Rangel-Cárdenas, E. R., Pérez-Hernández, R., Gómez-Cortés, A., & Castañeda-Guzmán, R. (2018). ZnO thin films deposited by RF magnetron sputtering: Effects of the annealing and atmosphere conditions on the photocatalytic hydrogen production. International Journal of Hydrogen Energy, 43(22), 10301–10310. https://doi.org/10.1016/j.ijhydene.2018.04.102
[40] Ahumada-Lazo, R., Hernández-Gordillo, A., & Camacho-López, M. (2014). Photocatalytic efficiency of reusable ZnO thin films deposited by sputtering technique. Applied Surface Science, 322, 35–40. https://doi.org/10.1016/j.apsusc.2014.10.038
[41] Kayaci, F., Vempati, S., Donmez, I., Biyikli, N., & Uyar, T. (2014). Role of zinc interstitials and oxygen vacancies of ZnO in photocatalysis. Nanoscale, 6(10), 5735–5745. https://doi.org/10.1039/C3NR06665K
[42] Maldonado Alvarez, A., Rebollar Rivera, Z., & Olvera Amador, M. L. (2019). Effect of thickness on photocatalytic properties of ZnO thin films deposited by RF magnetron sputtering. Proceedings of the 16th International Conference on Electrical Engineering, Computing Science and Automatic Control (CCE), 1–4. https://doi.org/10.1109/ICEEE.2019.8884521
[43] Widyastuti, W., Putri, N. P., & Syarif, N. (2023). Photocatalytic antimicrobial and photostability studies of TiO₂/ZnO thin films. Arabian Journal of Chemistry, 16(10), 105010. https://doi.org/10.1016/j.arabjc.2023.105010
[44] Talebian, N., & Nilforoushan, M. R. (2010). Comparative study of metal oxide thin films for photocatalytic degradation of organic pollutants. Thin Solid Films, 518, 2210–2215. https://doi.org/10.1016/j.tsf.2009.09.001
[45] Ćwik, K., Zawadzki, J., Zybała, R., Ożga, M., Witkowski, B., Wojnar, P., & Borysiewicz, M. A. (2024). Magnetron sputtering as a solvent-free method for fabrication of nanoporous ZnO thin films for highly efficient photocatalytic organic pollution degradation. Compounds, 4, 534–547. https://doi.org/10.3390/compounds4040034
[46] Riaz, A., Ashraf, A., Taimoor, H., Javed, S., Akram, M. A., Islam, M., Mujahid, M., Ahmad, I., & Saeed, K. (2019). Photocatalytic and photostability behavior of Ag- and/or Al-doped ZnO films in methylene blue and rhodamine B under UV-C irradiation. Coatings, 9(3), 202. https://doi.org/10.3390/coatings9030202

Details

Primary Language

English

Subjects

Materials Engineering (Other)

Journal Section

Research Article

Authors

Ahmet Çetin ^*
0009-0003-6991-656X
Türkiye

Mehmet Şimşir
0000-0002-8895-7821
Türkiye

Ebru Senadim Tuzemen
0000-0001-9166-7422
Türkiye

Ali Özer
0000-0002-4207-8207
Türkiye

Publication Date

February 27, 2026

Submission Date

November 5, 2025

Acceptance Date

February 5, 2026

Published in Issue

Year 2026 Volume: 47 Number: 1

DOI

https://doi.org/10.17776/csj.1818153

IZ

https://izlik.org/JA77ZM26EM

Cite

RIS / Bibtex

APA

Çetin, A., Şimşir, M., Senadim Tuzemen, E., & Özer, A. (2026). Investigation of Structural and Photocatalytic Properties of ZnO Thin Films. Cumhuriyet Science Journal, 47(1), 119-127. https://doi.org/10.17776/csj.1818153