Optical, structural, and morphological characterization of hydrothermally synthesized zinc oxide nanorods: exploring their potential for environmental applications
Source abstract
Abstract
Abstract This study presents the synthesis and multifunctional evaluation of nanostructured zinc oxide nanorods (ZnO NRs) using a hydrothermal method. Various characterisation techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible (UV–vis) spectrometry, fluorescence spectroscopy, energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), were employed to analyse the ZnO NRs. XRD analysis confirmed the hexagonal wurtzite structure of the ZnO NRs. FTIR spectra showed a characteristic peak near 873 cm −1 corresponding to Zn–O stretching and out-of-plane C–H bending vibrations, indicating surface interactions. UV–vis analysis revealed strong absorption in the UV region and high optical transparency in the visible range, while the Tauc plot determined bandgaps of 3.29 ± 0.03 eV and 3.66 ± 0.01 eV, which enhance electron transfer processes during photocatalysis. The fluorescence spectrum displayed a sharp emission peak at 340 nm, attributed to near-band-edge emission and quantum confinement effects. SEM and TEM micrographs showed well-dispersed, rod-like nanoparticles with an average width of 47.7 nm. EDS confirmed high purity with 60 % Zn and 20 % O, while XPS verified the successful incorporation of ZnO within the thin-film coating. The ZnO NRs demonstrated strong photocatalytic performance in degrading crystal violet (CV) dye under solar light, achieving over 95 % ± 0.01 degradation with a rate constant of 0.6767 min −1 . Hydrophobicity testing using a contact angle goniometer revealed a contact angle of 95.6° ± 0.3, indicating potential self-cleaning properties. XPS analysis further confirmed the presence of ZnO NRs within the thin-film coating and validated their successful incorporation. These findings collectively highlight the effectiveness of ZnO NRs in photocatalytic and surface coating applications, suggesting their promising potential for environmental and industrial use.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: ZnO doping and properties · Ga2O3 and related materials · Advanced Photocatalysis Techniques
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
King Abdullah Institute of Nanotechnology , King Saud University , Riyadh 11451 , Saudi Arabia
Department of Chemistry, College of Science , King Saud University , Riyadh 11451 , Saudi Arabia
References (63)
Show source-provided references
1. Saadi, H, Khaldi, O, Pina, J, Costa, T, Seixas de Melo, JS, Vilarinho, P, et al.. Effect of Co doping on the physical properties and organic pollutant photodegradation efficiency of ZnO nanoparticles for environmental applications. Nanomaterials 2024;14:122. https://doi.org/10.3390/nano14010122.10.3390/nano14010122 ↗
2. Madi, K, Chebli, D, Ait Youcef, H, Tahraoui, H, Bouguettoucha, A, Kebir, M, et al.. Green fabrication of ZnO nanoparticles and ZnO/rGO nanocomposites from Algerian date syrup extract: synthesis, characterization, and augmented photocatalytic efficiency in methylene blue degradation. Catalysts 2024;14:62. https://doi.org/10.3390/catal14010062.10.3390/catal14010062 ↗
3. Agarwal, H, Kumar, SV, Rajeshkumar, S. A review on green synthesis of zinc oxide nanoparticles – an eco-friendly approach. Resour Efficient Technol 2017;3:406–13. https://doi.org/10.18799/24056529/2017/4/163.10.1016/j.reffit.2017.03.002 ↗
4. Rasool, A, Sri, S, Zulfajri, M, Krismastuti, FSH. Nature inspired nanomaterials: advancements in green synthesis for biological sustainability. Inorg Chem Commun 2024;169:112954. https://doi.org/10.1016/j.inoche.2024.112954.10.1016/j.inoche.2024.112954 ↗
5. Senthil, RB, Ewe, LS, S, S, S, S, Yew, WK, Tiong, SK, et al.. Recent trends and advancement in metal oxide nanoparticles for the degradation of dyes: synthesis, mechanism, types and its application. Nanotoxicology 2024;18:272–98. https://doi.org/10.1080/17435390.2024.2349304.10.1080/17435390.2024.2349304 ↗
6. Kaveh, R, Alijani, H, Falletta, E, Bianchi, CL, Mokhtarifar, M, Boffito, DC. Advancements in superhydrophilic titanium dioxide/graphene oxide composite coatings for self-cleaning applications on glass substrates: a comprehensive review. Prog Org Coat 2024;190:108347. https://doi.org/10.1016/j.porgcoat.2024.108347.10.1016/j.porgcoat.2024.108347 ↗
7. Baig, A, Siddique, M, Panchal, S. A review of visible-light-active zinc oxide photocatalysts for environmental application. Catalysts 2025;15:100. https://doi.org/10.3390/catal15020100.10.3390/catal15020100 ↗
8. Kumari, H, Sonia, S, Ranga, R, Chahal, S, Devi, S, Sharma, S, et al.. A review on photocatalysis used for wastewater treatment: dye degradation. Water Air Soil Pollut 2023;234:349. https://doi.org/10.1007/s11270-023-06359-9.10.1007/s11270-023-06359-9 ↗
9. Ansari, AS, Azzahra, G, Nugroho, FG, Mujtaba, MM, Ahmed, ATA. Oxides and metal oxide/carbon hybrid materials for efficient photocatalytic organic pollutant removal. Catalysts 2025;15:134. https://doi.org/10.3390/catal15020134.10.3390/catal15020134 ↗
10. Chen, D, Cheng, Y, Zhou, N, Chen, P, Wang, Y, Li, K, et al.. Photocatalytic degradation of organic pollutants using TiO2-based photocatalysts: a review. J Clean Prod 2020;268:121725. https://doi.org/10.1016/j.jclepro.2020.121725.10.1016/j.jclepro.2020.121725 ↗
11. Varma, KS, Tayade, RJ, Shah, KJ, Joshi, PA, Shukla, AD, Gandhi, VG. Photocatalytic degradation of pharmaceutical and pesticide compounds (PPCs) using doped TiO2 nanomaterials: a review. Water-Energy Nexus 2020;3:46–61. https://doi.org/10.1016/j.wen.2020.03.008.10.1016/j.wen.2020.03.008 ↗
12. Qi, K, Cheng, B, Yu, J, Ho, W. Review on the improvement of the photocatalytic and antibacterial activities of ZnO. J Alloys Compd 2017;727:792–820. https://doi.org/10.1016/j.jallcom.2017.08.142.10.1016/j.jallcom.2017.08.142 ↗
13. Khan, ME. State-of-the-art developments in carbon-based metal nanocomposites as a catalyst: photocatalysis. Nanoscale Adv 2021;3:1887–900. https://doi.org/10.1039/d1na00041a.10.1039/D1NA00041A ↗
14. Ankita, Rathee, T, Sapana, Chahal, S, Kumar, S Kumar, Aet al.. Growth of advanced oxide nanostructures (nanocubes/nanorods/nanoflowers). In: Defect-induced magn oxide semiconductors. Cambridge: Woodhead Publishing; 2023, 223:223–44 pp.10.1016/B978-0-323-90907-5.00020-8 ↗
15. Rong, P, Ren, S, Yu, Q. Fabrications and applications of ZnO nanomaterials in flexible functional devices – a review. Crit Rev Anal Chem 2019;49:336–49. https://doi.org/10.1080/10408347.2018.1531691.10.1080/10408347.2018.1531691 ↗
16. Laurenti, M, Stassi, S, Canavese, G, Cauda, V. Surface engineering of nanostructured ZnO surfaces. Adv Mater Interfaces 2017;4:1600758. https://doi.org/10.1002/admi.201600758.10.1002/admi.201600758 ↗
17. Khan, MM, Saadah, NH, Khan, ME, Harunsani, MH, Tan, AL, Cho, MH. Phytogenic synthesis of band gap-narrowed ZnO nanoparticles using the bulb extract of Costus woodsonii. BioNanoScience 2019;9:334–44. https://doi.org/10.1007/s12668-019-00616-0.10.1007/s12668-019-00616-0 ↗
18. Raha, S, Ahmaruzzaman, M. ZnO nanostructured materials and their potential applications: progress, challenges and perspectives. Nanoscale Adv 2022;4:1868–925. https://doi.org/10.1039/d1na00880c.10.1039/D1NA00880C ↗
19. Sharwani, AA, Narayanan, KB, Khan, ME, Han, SS. Photocatalytic degradation activity of goji berry extract synthesized silver-loaded mesoporous zinc oxide (Ag@ZnO) nanocomposites under simulated solar light irradiation. Sci Rep 2022;12:10017. https://doi.org/10.1038/s41598-022-14117-w.10.1038/s41598-022-14117-w ↗
20. Zhu, J, Liao, K. A facile method for preparing a superhydrophobic block with rapid reparability. Coatings 2020;10:1202. https://doi.org/10.3390/coatings10121202.10.3390/coatings10121202 ↗
21. Gao, X, Wen, G, Guo, Z. Durable superhydrophobic and underwater superoleophobic cotton fabrics growing zinc oxide nanoarrays for separation of heavy/light oil and water mixtures. Colloids Surf A Physicochem Eng Asp 2018;559:115–26. https://doi.org/10.1016/j.colsurfa.2018.09.041.10.1016/j.colsurfa.2018.09.041 ↗
22. Nundy, S, Ghosh, A, Mallick, TK. Hydrophobic and superhydrophobic self-cleaning coatings by morphologically varying ZnO microstructures for photovoltaic and glazing applications. ACS Omega 2020;5:1033–9. https://doi.org/10.1021/acsomega.9b02758.10.1021/acsomega.9b02758 ↗
23. Markevich, I, Stara, T, Khomenkova, L, Kushnirenko, V, Borkovska, L. Photoluminescence engineering in polycrystalline ZnO and ZnO-based compounds. AIMS Mater Sci 2016;3:508–24. https://doi.org/10.3934/matersci.2016.2.508.10.3934/matersci.2016.2.508 ↗
24. Kaningini, AG, Azizi, S, Sintwa, N, Mokalane, K, Mohale, KC, Mudau, FN, et al.. Effect of optimized precursor concentration, temperature, and doping on optical properties of ZnO nanoparticles synthesized via a green route using bush tea (Athrixia phylicoides DC.) leaf extracts. ACS Omega 2022;7:31658–66. https://doi.org/10.1021/acsomega.2c00530.10.1021/acsomega.2c00530 ↗
25. Manal, AA, Hendi, A, Ortashi, K, Alnamlah, R, Alangery, A, Ali Alshaya, E, et al. Utilizing cymbopogon Proximus grass extract for green synthesis of zinc oxide nanorod needles in dye degradation studies. Molecules 2024;29:355.10.3390/molecules29020355 ↗
26. Alterary, ٍSS. Potent and versatile biogenically synthesized alumina/nickel oxide nanocomposite adsorbent for defluoridation of drinking water. ACS Omega 2024;9:23220–40. https://doi.org/10.1021/acsomega.3c09076.10.1021/acsomega.3c09076 ↗
27. Estrada-Urbina, J, Cruz-Alonso, A, Santander-González, M, Méndez-Albores, A, Vázquez-Durán, A. Nanoscale zinc oxide particles for improving the physiological and sanitary quality of a Mexican landrace of red maize. Nanomaterials 2018;8:247. 195207. https://doi.org/10.3390/nano8040247..10.3390/nano8040247 ↗
28. Shankar, S, Wang, LF, Rhim, JW. Zinc oxide nanoparticle incorporation improves mechanical, water vapor barrier, UV-light barrier and antibacterial properties of PLA nanocomposite films. Mater Sci Eng C 2018;93:289–98. e202400203. https://doi.org/10.1016/j.msec.2018.08.002..10.1016/j.msec.2018.08.002 ↗
29. Pudukudy, M, Yaakob, Z. Facile synthesis of quasi-spherical ZnO nanoparticles with excellent photocatalytic activity. J Cluster Sci 2015;26:1187–201. https://doi.org/10.1007/s10876-014-0806-1.10.1007/s10876-014-0806-1 ↗
30. Karthikeyan, B, Gnanakumar, G, Alphonsa, AT. Nano metal oxides. Singapore: Springer; 2023.10.1007/978-981-19-9444-9 ↗
31. Teke, A, Özgür, Ü, Doğan, S, Morkoç, H, Nemeth, B, Everitt, HO. Excitonic fine structure and recombination dynamics in single-crystalline ZnO. Phys Rev B 2004;70:195207. https://doi.org/10.1103/physrevb.70.195207.10.1103/PhysRevB.70.195207 ↗
32. Podia, M, Tripathi, AK. Structural, optical and luminescence properties of ZnO thin films: role of hot electrons defining luminescence mechanisms. J Lumin 2022;252:119331. https://doi.org/10.1016/j.jlumin.2022.119331.10.1016/j.jlumin.2022.119331 ↗
33. Mascoli, V, Bhatti, AF, Bersanini, L, van Amerongen, H, Croce, R. The antenna of far-red absorbing cyanobacteria increases both absorption and quantum efficiency of photosystem II. Nat Commun 2022;13:3562. https://doi.org/10.1038/s41467-022-31099-5.10.1038/s41467-022-31099-5 ↗
34. Wang, C. Luminescent transition metal complexes: optical characterization, integration into polymeric nanoparticles and sensing applications. Berlin: Freie Universität Berlin; 2021.
35. Bulcha, B, Leta Tesfaye, J, Anatol, D, Shanmugam, R, Dwarampudi, LP, Nagaprasad, N, et al.. Synthesis of zinc oxide nanoparticles by hydrothermal methods and spectroscopic investigation of ultraviolet radiation protective properties. J Nanomater 2021;2021:1–10. https://doi.org/10.1155/2021/8617290.10.1155/2021/8617290 ↗
36. Javed, A, Wiener, J, Tamulevičienė, A, Tamulevičius, T, Lazauskas, A, Saskova, J, et al.. One-step in situ synthesis of zinc oxide nanoparticles for multifunctional cotton fabrics. Materials 2021;14:3956. https://doi.org/10.3390/ma14143956.10.3390/ma14143956 ↗
37. Awad, MA, Hendi, AA, Ortashi, KM, Alnamlah, RA, Alangery, A, Alshaya, EA, et al.. Utilizing cymbopogon proximus grass extract for green synthesis of zinc oxide nanorod needles in dye degradation studies. Molecules 2024;29:355. https://doi.org/10.3390/molecules29020355.10.3390/molecules29020355 ↗
38. Nguyen, TP, Tan, PB, Le, T. Effect of poly(vinyl alcohol) (PVA) capping agent on structural, photoluminescent and photometric properties of ZnO nanoparticles. Opt Mater 2022;125:112132. https://doi.org/10.1016/j.optmat.2022.112132.10.1016/j.optmat.2022.112132 ↗
39. Motelica, L, Vasile, BS, Ficai, A, Surdu, AV, Ficai, D, Oprea, OC, et al.. Antibacterial activity of zinc oxide nanoparticles loaded with essential oils. Pharmaceutics 2023;15:2470. https://doi.org/10.3390/pharmaceutics15102470.10.3390/pharmaceutics15102470 ↗
40. Falamas, A, Maric, I, Nekvapil, F, Stefan, M, Macavei, GS, Barbu-Tudoran, L, et al.. Surface enhanced fluorescence potential of ZnO nanoparticles and gold decorated ZnO nanostructures embedded in a polyvinyl alcohol matrix. J Photochem Photobiol A: Chem 2023;438:114516. https://doi.org/10.1016/j.jphotochem.2022.114516.10.1016/j.jphotochem.2022.114516 ↗
41. Shakeel, N, Piwoński, I, Kisielewska, A, Krzywiecki, M, Batory, D, Cichomski, M. Morphology-dependent photocatalytic activity of nanostructured titanium dioxide coatings with silver nanoparticles. Int J Mol Sci 2024;25:8824. https://doi.org/10.3390/ijms25168824.10.3390/ijms25168824 ↗
42. Meky, AI, Hassaan, MA, Fetouh, HA, Ismail, AM, El Nemr, A. Hydrothermal fabrication, characterization and RSM optimization of cobalt-doped zinc oxide nanoparticles for antibiotic photodegradation under visible light. Sci Rep 2024;14:2016. https://doi.org/10.1038/s41598-024-52430-8.10.1038/s41598-024-52430-8 ↗
43. Mardosaite, R, Jurkeviciute, A, Rackauskas, S. Superhydrophobic ZnO nanowires: wettability mechanisms and functional applications. Cryst Growth Des 2021;21:4765–79. https://doi.org/10.1021/acs.cgd.1c00449.10.1021/acs.cgd.1c00449 ↗
44. Althamthami, M, Temam, HB, Temam, EG, Rahmane, S, Gasmi, B, Hasan, GG. Impact of surface topography and hydrophobicity in varied precursor concentrations of tenorite (CuO) films: film properties and photocatalytic efficiency. Sci Rep 2024;14:7928. https://doi.org/10.1038/s41598-024-58744-x.10.1038/s41598-024-58744-x ↗
45. Mohammed, M, Rahman, R, Mohammed, AM, Betar, BO, Osman, AF, Adam, T, et al.. Improving hydrophobicity and compatibility between kenaf fiber and polymer composite by surface treatment with inorganic nanoparticles. Arab J Chem 2022;15:104233. https://doi.org/10.1016/j.arabjc.2022.104233.10.1016/j.arabjc.2022.104233 ↗
46. Al-Shatty, W, Lord, AM, Alexander, S, Barron, AR. Tunable surface properties of aluminum oxide nanoparticles from highly hydrophobic to highly hydrophilic. ACS Omega 2017;2:2507–14. https://doi.org/10.1021/acsomega.7b00279.10.1021/acsomega.7b00279 ↗
47. Huang, CY, Ko, CC, Chen, LH, Huang, CT, Tung, KL, Liao, YC. Simple coating method to prepare superhydrophobic layers on ceramic alumina for vacuum membrane distillation. Sep Purif Technol 2018;198:79–86. https://doi.org/10.1016/j.seppur.2016.12.037.10.1016/j.seppur.2016.12.037 ↗
48. Li, Y, Xia, B, Jiang, B. Thermal-induced durable superhydrophilicity of TiO2 films with ultra-smooth surfaces. J Sol Gel Sci Technol 2018;87:50–8. https://doi.org/10.1007/s10971-018-4684-0.10.1007/s10971-018-4684-0 ↗
49. Wang, W, Lv, L, Wang, C, Li, J. Melamine-assisted thermal activation for vacancy-rich ZnO: calcination effects on microstructure and photocatalytic properties. Molecules 2023;28:5329. https://doi.org/10.3390/molecules28145329.10.3390/molecules28145329 ↗
50. Lu, J, Ali, H, Hurh, J, Han, Y, Batjikh, I, Rupa, EJ, et al.. Photocatalytic activity assessment of zinc oxide nanoparticles synthesized from Codonopsis lanceolata roots by one-pot green synthesis. Optik 2019;184:82–9. https://doi.org/10.1016/j.ijleo.2019.03.050.10.1016/j.ijleo.2019.03.050 ↗
51. Abdi, M, Balagabri, M, Karimi, H, Hossini, H, Rastegar, SO. Degradation of crystal violet using ozone, peroxone, electroperoxone and electrolysis processes: a comparative study. Appl Water Sci 2020;10:1–10.10.1007/s13201-020-01252-w ↗
52. Anitha, S, Muthukumaran, S. Structural, optical and antibacterial investigation of La- and Cu-doped ZnO nanoparticles synthesized by co-precipitation. Mater Sci Eng C 2020;108:110387. https://doi.org/10.1016/j.msec.2019.110387.10.1016/j.msec.2019.110387 ↗
53. Khan, I, Saeed, K, Ali, N, Khan, I, Zhang, B, Sadiq, M. Heterogeneous photodegradation of industrial dyes: mechanisms and rate-affecting parameters. J Environ Chem Eng 2020;8:104364. https://doi.org/10.1016/j.jece.2020.104364.10.1016/j.jece.2020.104364 ↗
54. Tagnaouti Moumnani, F, Khallouk, K, Elkhalfaouy, R, Moussaid, D, Mertah, O, Solhy, A, et al.. Synthesis and characterization of Zn3V2O8 nanoparticles: mechanisms and factors influencing crystal violet photodegradation. React Kinet Mech Catal 2024:1–18.10.1007/s11144-023-02553-2 ↗
55. Ali, I, Alharbi, OM, Alothman, ZA, Badjah, AY. Photodegradation kinetics and thermodynamics of amido black dye over Co/TiO2 nanoparticles. Photochem Photobiol 2018;94:935–41. https://doi.org/10.1111/php.12937.10.1111/php.12937 ↗
56. Shubha, JP, Kavalli, K, Adil, SF, Assal, ME, Hatshan, MR, Dubasi, N. Green synthesis of ZnO nanoparticles for dye degradation: kinetic modeling approach. J King Saud Univ Sci 2022;34:102047. https://doi.org/10.1016/j.jksus.2022.102047.10.1016/j.jksus.2022.102047 ↗
57. Bayahia, H. High activity of ZnFe2O4 nanoparticles for sunlight-driven photodegradation of crystal violet dye. J Taibah Univ Sci 2022;16:988–1004. https://doi.org/10.1080/16583655.2022.2134696.10.1080/16583655.2022.2134696 ↗
58. Bano, K, Mittal, SK, Singh, PP, Kaushal, S. Sunlight-driven degradation of organic pollutants using MnV2O6/BiVO4 heterojunction photocatalyst. Nanoscale Adv 2021;3:6446–58. https://doi.org/10.1039/d1na00499a.10.1039/D1NA00499A ↗
59. Labhane, PK, Huse, VR, Patle, LB, Chaudhari, AL, Sonawane, GH. Synthesis and characterization of Cu-doped ZnO nanoparticles: optical, FTIR, morphological and photocatalytic study. J Mater Sci Chem Eng 2015;3:39.10.4236/msce.2015.37005 ↗
60. Eswaran, P, Madasamy, PD, Pillay, K, Brink, H. Sunlight-driven photocatalytic degradation of methylene blue using ZnO/biochar nanocomposite from banana peels. Biomass Convers Biorefinery 2024:1–21.10.1007/s13399-024-05999-z ↗
61. Aroob, S, Carabineiro, SA, Taj, MB, Bibi, I, Raheel, A, Javed, T, et al.. Green synthesis and photocatalytic activity of CuO nanoparticles. Catalysts 2023;13:502. https://doi.org/10.3390/catal13030502.10.3390/catal13030502 ↗
62. Anaya-Zavaleta, JC, Ledezma-Pérez, AS, Gallardo-Vega, C, Rodríguez-Hernández, J, Alvarado-Canché, CN, García-Casillas, PE, et al.. ZnO nanoparticles by hydrothermal method: synthesis and characterization. Technologies 2025;13:18. https://doi.org/10.3390/technologies13010018.10.3390/technologies13010018 ↗
63. Karagoz, S, Kiremitler, NB, Sarp, G, Pekdemir, S, Salem, S, Goksu, AG, et al.. Antibacterial, antiviral and self-cleaning ZnO/Ag nanofiber mats for protective clothing. ACS Appl Mater Interfaces 2021;13:5678–90. https://doi.org/10.1021/acsami.0c15606.10.1021/acsami.0c15606 ↗