Abstract

A low-temperature chemical precipitation (alkaline precipitation) route suitable for scalable production synthesized copper oxide (CuO) nanoparticles. Aqueous copper nitrate was reacted with sodium hydroxide under strongly alkaline conditions (pH ≈ 14) to form a Cu(OH)₂ precursor, followed by washing, drying (120 °C) and thermal dehydration (200 °C) to obtain CuO nanoparticles. Phase identification and crystallinity were examined by X-ray diffraction (XRD), functional group/bond confirmation by Fourier transform infrared spectroscopy (FTIR), and morphology by field-emission scanning electron microscopy (FESEM). XRD patterns confirmed the formation of phase-pure monoclinic tenorite CuO with no detectable impurity phases. The average crystallite size was estimated as ~49.01 nm using the Debye–Scherrer equation. FTIR spectra showed characteristic Cu–O stretching vibrations (≈500–600 cm⁻¹), supporting complete oxide formation and phase purity. FESEM images indicated nearly spherical CuO nanoparticles with relatively uniform distribution and minor agglomeration, consistent with rapid nucleation under strong alkalinity. Overall, the results demonstrate that alkaline chemical precipitation followed by mild heat treatment is a simple, low-cost and reproducible method for producing phase-pure CuO nanoparticles, providing a reliable materials platform for catalysis, sensing and energy-related applications.

Keywords

Copper Oxide (Cuo) Nanoparticles, Chemical Precipitation, Alkaline Precipitation, Monoclinic Tenorite Cuo, XRD–FTIR–FESEM Characterization, Debye–Scherrer Crystallite Size,

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References

  1. R. Rajamani, C. Van Nguyen, Plasma-Assisted synthesis and engineering of functional nanomaterials: from metal nanoparticles to 2D architectures. NanoNEXT, 6(4), (2025) 10–47. https://doi.org/10.54392/nnxt2542
  2. A.S. John, K. Gurumurthy, Synthesis and Characterization of CuO Nanoparticles from Bioleached Copper through Modified and Optimized Double Precipitation Method. ACS Omega, 10(10), (2025) 10193–10198. https://doi.org/10.1021/acsomega.4c09064
  3. M.D. Moroda, T.L. Deressa, A.H. Tiwikrama, T.F. Chala, Green synthesis of copper oxide nanoparticles using Rosmarinus officinalis leaf extract and evaluation of its antimicrobial activity. Next Materials, 7, (2024) 100337. https://doi.org/10.1016/j.nxmate.2024.100337
  4. S. Srimathi, V. Kalaiselvi, P. Yasotha, B. Blessymol, S. Gopi, Plant-Mediated Synthesis of TiO₂–ZnO Nanocomposites Using Nigella sativa Seeds for Solar Energy Applications. NanoNEXT, 6(3), (2025) 1–8. https://doi.org/10.54392/nnxt2531
  5. T.H. Tran, V.T. Nguyen, Copper Oxide nanomaterials Prepared by solution methods, some properties, and potential applications: A Brief review. International Scholarly Research Notices, 2014, (2014) 1–14. https://doi.org/10.1155/2014/856592
  6. S. Rakshit, K.G. Mondal, B.S. Kar, T.N. Ghosh, D. Maji, M.N. Goswami, P.C. Jana, Enhanced structural, optical and electrical properties of Cu2O and CuO nanoparticles for electrochemical energy storage devices. Journal of Alloys and Compounds, 1024, (2025) 180274. https://doi.org/10.1016/j.jallcom.2025.180274
  7. C. Lin, J. Liao, Production of CuO nanoparticles using a simple precipitation method in a rotating packed bed with blade packings. Journal of Alloys and Compounds, 775, (2018) 419–426. https://doi.org/10.1016/j.jallcom.2018.09.187
  8. A. Vinukonda, N. Bolledla, R.K. Jadi, R. Chinthala, V.R. Devadasu, Synthesis of nanoparticles using advanced techniques. Next Nanotechnology, 8, (2025) 100169. https://doi.org/10.1016/j.nxnano.2025.100169
  9. Y. Li, Y. Lu, K. Wu, D. Zhang, M. Debliquy, C. Zhang, Microwave‐assisted hydrothermal synthesis of copper oxide‐based gas‐sensitive nanostructures. Rare Metals, 40(6), (2020) 1477–1493. https://doi.org/10.1007/s12598-020-01557-4
  10. B. Cardoso, G. Nobrega, I.S. Afonso, J.E. Ribeiro, R.A. Lima, Sustainable green synthesis of metallic nanoparticle using plants and microorganisms: A review of biosynthesis methods, mechanisms, toxicity, and applications. Journal of Environmental Chemical Engineering, 13(3), (2025) 116921. https://doi.org/10.1016/j.jece.2025.116921
  11. K. Phiwdang, S. Suphankij, W. Mekprasart, W. Pecharapa, Synthesis of CUO nanoparticles by precipitation method using different precursors. Energy Procedia, 34, (2013) 740–745. https://doi.org/10.1016/j.egypro.2013.06.808
  12. E.Y. Shaba, J.O. Jacob, J.O. Tijani, M.a.T. Suleiman, A critical review of synthesis parameters affecting the properties of zinc oxide nanoparticle and its application in wastewater treatment. Applied Water Science, 11(2), (2021). https://doi.org/10.1007/s13201-021-01370-z
  13. S. Suresh, S. Karthikeyan, K. Jayamoorthy, FTIR and multivariate analysis to study the effect of bulk and nano copper oxide on peanut plant leaves. Journal of Science Advanced Materials and Devices, 1(3), (2016) 343–350. https://doi.org/10.1016/j.jsamd.2016.08.004
  14. Y.S. Jara, E.T. Mohammed, T.T. Mekiso, Biosynthesized pure CuO, N-CuO, Zn-CuO, and N-Zn-CuO nanoparticles for photocatalytic activity: Enhanced optical properties through bandgap engineering. Next Materials, 8, (2025) 100742. https://doi.org/10.1016/j.nxmate.2025.100742
  15. M.S. Dehaj, M.Z. Mohiabadi, Experimental study of water-based CuO nanofluid flow in heat pipe solar collector. Journal of Thermal Analysis and Calorimetry, 137(6), (2019) 2061–2072. https://doi.org/10.1007/s10973-019-08046-6
  16. V.T. Jeielayaganga, M. Venkatesh, Tailoring the electrochemical properties of Ni-doped Co3O4 for advanced supercapacitor electrodes. Journal of the Indian Chemical Society, 102(11), (2025) 102170. https://doi.org/10.1016/j.jics.2025.102170
  17. T.Q. Tazim, M. Kawsar, M.S. Hossain, N.M. Bahadur, S. Ahmed, Hydrothermal synthesis of nano-metal oxides for structural modification: A review. Next Nanotechnology, 7, (2025) 100167. https://doi.org/10.1016/j.nxnano.2025.100167
  18. S.S. Krishnappa, S. Kalikeri, Calcination-tuned copper oxide nanoparticles for tomato seedling growth and vigour through nano-priming. Next Materials, 11, (2026) 101638. https://doi.org/10.1016/j.nxmate.2026.101638
  19. V.T. Jeielayaganga, M. Venkatesh, Influence of pH on the size and morphology of cobalt oxide nanostructures synthesized via microwave-assisted method. MRS Advances, 10(17), (2025) 2103–2111. https://doi.org/10.1557/s43580-025-01452-z
  20. C. Lin, Y. Wei, Enhanced reactivity of copper nanoparticles mass-produced by reductive precipitation in a rotating packed bed with blade packings. Journal of Materials Research and Technology, 9(6), (2020) 12328–12334. https://doi.org/10.1016/j.jmrt.2020.08.080
  21. M.A. Hessien, R.M. Khattab, H.E.H. Sadek, Synthesis and characterization of ZNO, MN3O4, and ZNMN2O4 spinel by new Chelation-Precipitation method: magnetic and antimicrobial properties. Journal of Inorganic and Organometallic Polymers and Materials, 35(5), (2024) 3739–3758. https://doi.org/10.1007/s10904-024-03489-3
  22. V. Molahalli, A. Sharma, K. Bijapur, G. Soman, A. Shetty, B. Sirichandana, B.G. M. Patel, N. Chattham, G. Hegde, Properties, synthesis, and characterization of CU-Based nanomaterials. In ACS symposium series, (2024) 1–33. https://doi.org/10.1021/bk-2024-1466.ch001
  23. R.M. Alhuthli, F.A. Alrahmany, B.a.A. Jahdaly, Electrocatalytic oxygen evolution on nano-CuOx modified electrodes: enhanced activity and stability through surface oxidation engineering. Results in Chemistry, 20, (2025) 103004. https://doi.org/10.1016/j.rechem.2025.103004
  24. J. Neiva, Z. Benzarti, S. Carvalho, S. Devesa, Green synthesis of CUO Nanoparticles—Structural, morphological, and dielectric characterization. Materials, 17(23), (2024) 5709. https://doi.org/10.3390/ma17235709
  25. Ratnawulan, A. Fauzi, S.H. Ae, Effect of calcination temperature on phase transformation and crystallite size of copper oxide (CuO) powders. AIP Conference Proceedings, 1868, (2017) 060009. https://doi.org/10.1063/1.4995173
  26. P.K. Kermanshahi, S. Estaji, E. Zivari, S. Moghari, P.A. Poshtahani, S. Moftakhari, H.A. Khonakdar, A comprehensive review on electroactive MOF-reinforced nanocomposites: From material design to practical applications. Materials Today Sustainability, 32, (2025) 101229. https://doi.org/10.1016/j.mtsust.2025.101229
  27. U. Sidiqi, M. Ubaidullah, A. Kumar, D. Kumar, K. Muzammil, M. Imran, Progress on cupric oxide based nanomaterials: Exploring advancements in their synthesis, applications and prospects. Materials Science and Engineering B, 308, (2024) 117598. https://doi.org/10.1016/j.mseb.2024.117598
  28. X. Wang, K. Klingan, M. Klingenhof, T. Möller, J.F. De Araújo, I. Martens, A. Bagger, S. Jiang, J. Rossmeisl, H. Dau, P. Strasser, Morphology and mechanism of highly selective Cu(II) oxide nanosheet catalysts for carbon dioxide electroreduction. Nature Communications, 12(1), (2021) 794. https://doi.org/10.1038/s41467-021-20961-7