Studies of structural, optical, and electrical properties associated with defects in sodium-doped copper oxide (CuO/Na) nanostructures
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In the present paper, we report a detailed study on the sodium (Na) doping-induced modifications in the copper oxide (CuO) nanostructure and its properties. A facile and sustainable sol–gel synthesis approach was employed for the preparation of high-quality pristine CuO- and Na-doped CuO nanostructures(1.0, 3.0, 5.0 and 7.0 mol% doping levels, CuO/Na) with controlled shape and composition. Due to the remarkable difference in the ionic radii of Cu2+ (0.73 Å) and Na+ (1.02 Å), Na+ substitution in place of Cu2+ generates strain/distortions in CuO lattice. The XRD analysis reveal the structural alteration from monoclinic to cubic symmetry with increase in doping level and also reveal the phase purity up to 3% doping level, and beyond this (i.e., for 5 and 7% doping level) small amount of impurity phase corresponding to Na2O was observed. The FTIR results further confirmed the presence of the Na–Cu–O stretching vibrations at higher Na-doped samples. Morphology of the samples indicates that the Na-doped CuO nanostructures exhibit less agglomeration compared to pristine CuO nanoparticles. The presence of Na in CuO lattice were found to greatly enhances optical and electrical properties owing to the formation of defects like copper vacancies and oxygen vacancies at the grain boundaries of the nanoparticles with increased doping of Na.
Hafsa Siddiqui and Mohammad Ramzan Parra deeply acknowledge the UGC, New Delhi, and HRDG-CSIR for the financial support given in the form of UGC-MANF videno. F1-17.1/2011-12/MANF-MUS-MAD-4694 and CSIR-SRF Ack. No. 163320/2K14/1, respectively. Authors would like to acknowledge the Director-UGC-DAE-CSR, Indore Centre for performing XRD, Raman, FTIRand UV–Vis–NIR measurements. The authors are grateful to the USIF, Aligarh Muslim University, for providing the TEM facility.
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Conflict of interest
The authors declare that they have no conflict of interests. Also all authors are entirely responsible for the content and writing of the paper.
- 2.Abu-Zied BM, Bawaked SM, Kosa SA, Schwieger W (2016) Impact of Gd-, La-, Nd- and Y-doping on the textural, electrical conductivity and N2O decomposition activity of CuO catalyst. Int J Electrochem Sci 11:2230–2246Google Scholar
- 3.Abu-Zied BM, Bawaked SM, Kosa SA, Schwieger W (2016) Effect of some rare earth oxides doping on the morphology, crystallite size, electrical conductivity and N2O decomposition activity of CuO catalyst. Int J Electrochem Sci 11:1568–1580Google Scholar
- 9.Siddiqui H, Qureshi MS, Haque FZ (2014) Structural and optical properties of CuO nanocubes prepared through simple hydrothermal route. Int J Sci Eng Res 5(3):173–177Google Scholar
- 14.Faiz H, Siraj K, Khan MF, Irshad M, Majeed S, Rafique MS, Naseem S (2016) Microstructural and optical properties of dysprosium doped copper oxide thin films fabricated by pulsed laser deposition technique. J Mater Sci: Mater Electron 27:8197–8205Google Scholar
- 15.Wang D, Wang Y, Jiang T, Jia H, Yu M (2016) The preparation of M (M: Mn2+, Cd2+, Zn2+)-doped CuO nanostructures via the hydrothermal method and their properties. J Mater Sci: Mater Electron 27:2138–2145Google Scholar
- 22.Vidhya SN, Balasundaram ON, Chandramohan M (2015) Influence of doping concentration on the properties of Ga doped CuO thin films by the spray pyrolysis technique. J Optoelectron Adv Mater 17(7):963–967Google Scholar
- 24.Wu J, Hui KS, Hui KN, Li L, Chun HH, Cho YR (2016) Characterization of Sn-doped CuO thin films prepared by a sol–gel method. J Mater Sci: Mater Electron 27:1719–1724Google Scholar
- 34.Etefagh R, Azhir E, Shahtahmasebi N (2013) Synthesis of CuO nanoparticles and fabrication of nanostructural layer biosensors for detecting Aspergillus niger fungi. Sci Iran 20(3):1055–1058Google Scholar
- 55.Kondofersky IT (2016) Design of photoelectrode morphologies for solar-driven water splitting. Ph.D. Thesis, Der Ludwig-Maximilians-Universität MünchenGoogle Scholar
- 61.Sukhorukov YP, Loshkareva NN, Samokhvalov AA, Moskvin AS (1995) Absorption spectra of CuO single crystals near the absorption edge and the nature of the optical gap in copper oxides. J Exp Theor Phys 81(5):998–1002Google Scholar
- 63.Balamurugan B, Mehta B, Avasthi D, Singh F, Arora A, Rajalakshmi M, Raghavan G, Tyagi A, Shivaprasad S (2002) Modifying the nanocrystalline characteristics-structure, size, and surface states of copper oxide thin films by high-energy heavy-ion irradiation. J Appl Phys 92:3304–3310CrossRefGoogle Scholar
- 65.Ahrens LH, Press F, Runcorn SK (2013) Physics and chemistry of the earth: progress series, vol 6. Elsevier Publication, Amsterdam, p 522Google Scholar
- 70.Priscilla SJ, Sivaji K, Vimaladevi L (2017) Synthesis and characterization of Na doped cupric oxide (CuO) nanoparticles. In: AIP conference proceedings, vol 1832. p 050128Google Scholar
- 72.Barsoukov E, Macdonald RJ (2005) Impedance spectroscopy: theory, experiment, and applications. 2nd edn. Wiley, HobokenGoogle Scholar