Journal of Sol-Gel Science and Technology

, Volume 87, Issue 1, pp 125–135 | Cite as

Optimization of process parameters and its effect on structure and morphology of CuO nanoparticle synthesized via the sol−gel technique

  • Hafsa Siddiqui
  • Mohammad Ramzan Parra
  • Fozia Z. HaqueEmail author
Original Paper: Nano-structured materials (particles, fibers, colloids, composites, etc.)


This article describes systematic basic research on the optimization of the processing parameters of sol−gel technique for synthesis of the high purity CuO nanoparticles. Effect of the synthesis parameters such as copper salt concentration, solvent and gelating agent, optimized one at a time, was investigated by employing XRD, TEM, FESEM, micro-Raman, UV-visible-NIR and PL spectroscopies. XRD results clearly demonstrate the monoclinic structure of CuO nanoparticles with traceable impurities at a lower molar concentration of Cu2+, transition of nucleation system from homogeneous to heterogeneous state with the increase in concentration of Cu2+ from 0.05 to 0.15 M. It was also found that the isopropyl alcohol offers better results in comparison to ethanol and water. Moreover, the lattice parameters, space group, and crystal system were determined by powder X-ray diffraction method. Further we propose the optimization of synthesis process using ethylene glycol and citric acid (EG:CA). The Raman analysis confirmed the influence of ethylene glycol and citric acid ratio and TEM observations confirmed that EG:CA 1:2 ratio formulate homogenous flower-like nanostructures. The optical absorption of CuO nanostructures can be easily tuned by varying the concentration of citric acid without changing other conditions; it shows the role of synthesis parameters more significant. Our results suggest that the prepared CuO nanostructures have a potential to be used as absorbing material in solar cell applications.


  • CuO nanoparticles are successfully synthesized via simple non-aqueous sol-gel method.

  • The effect of various process parameters on the morphology and structure of CuO nanoparticles are investigated.

  • Vibrant modifications in the morphology of CuO nanoparticles are detected via TEM and SEM.

  • Isopropyl alcohol gives better crystallization of CuO nanostructures in comparison to ethanol.

  • 1:2 ratio of ethylene glycol and citric acid yield superior assembly of CuO nanostructures.


CuO nanostructures Sol–gel technique Solvent Gelating agent Citric acid 



Ms. Hafsa Siddiqui and Mr. Mohammad Ramzan Parra deeply acknowledge the UGC, New Delhi, and HRDG-CSIR for the financial support given in the form of UGC-MANF reference no. F1-17.1/2011-12/MANF-MUS-MAD-4694 and CSIR-SRF ack. no. 163320/2K14/1. The authors would like to acknowledge the Director-UGC-DAE-Consortium for Scientific Research, Indore Centre (M.P.), India for performing XRD, Raman and UV−Vis-diffused reflectance measurements. The authors are very grateful to the USIF-AMU, Aligarh (U.P.) for the TEM facility, and Department of Physics and Astrophysics, University of Delhi, India for the FESEM facility.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

10971_2018_4663_MOESM1_ESM.doc (3.5 mb)
Electronic supplementary material


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018
Corrected publication June/2018

Authors and Affiliations

  1. 1.Optical Nanomaterials Lab, Department of PhysicsMaulana Azad National Institute of TechnologyBhopalIndia

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