Enhancement in the Structural, Electrical, Optical, and Photocatalytic Properties of La2O3-Doped ZnO Nanostructures

Vanga Ganesh; Thekrayat H AlAbdulaal; Manal AlShadidi; Mai S A Hussien; Abdelfatteh Bouzidi; Hamed Algarni; Heba Y Zahran; Mohamed Sh Abdel-Wahab; Mervat I Mohammed; Ibrahim S Yahia; Bayapa Reddy Narapureddy

doi:10.3390/ma15196866

Enhancement in the Structural, Electrical, Optical, and Photocatalytic Properties of La₂O₃-Doped ZnO Nanostructures

Materials (Basel). 2022 Oct 2;15(19):6866. doi: 10.3390/ma15196866.

Authors

Vanga Ganesh^{1

2}, Thekrayat H AlAbdulaal^{1

2}, Manal AlShadidi¹, Mai S A Hussien^{3

4}, Abdelfatteh Bouzidi^{5

6}, Hamed Algarni¹, Heba Y Zahran^{1

4}, Mohamed Sh Abdel-Wahab⁷, Mervat I Mohammed³, Ibrahim S Yahia^{1

2

4}, Bayapa Reddy Narapureddy⁸

Affiliations

¹ Laboratory of Nano-Smart Materials for Science and Technology (LNSMST), Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia.
² Research Center for Advanced Materials Science (RCAMS), King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia.
³ Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo 11757, Egypt.
⁴ Nanoscience Laboratory for Environmental and Bio-Medical Applications (NLEBA), Semiconductor Lab., Metallurgical Lab.1, Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo 11757, Egypt.
⁵ Research Unit, Physics of Insulating and Semi-Insulating Materials, Faculty of Sciences, University of Sfax, P.O. Box 1171, Sfax 3000, Tunisia.
⁶ Preparatory Year Program, Shaqra University, Al-Quwayiyah Branch, Shaqra 19248, Saudi Arabia.
⁷ Materials Science and Nanotechnology Department, Faculty of Postgraduate Studies for Advanced Sciences, Beni-Suef University, Beni Suef 62511, Egypt.
⁸ Department of Public Health, College of Applied Medical Sciences, King Khalid University, Asir Region, P.O. Box 61421, Abha 61413, Saudi Arabia.

Abstract

A lanthanum oxide (La₂O₃)-ZnO nanostructured material was synthesized in the proposed study with different La₂O₃ concentrations, 0.001 g to 5 g (named So to S7), using the combustion method. X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transformation infrared spectroscopy (FT-IR) were utilized for investigating the structure, morphology, and spectral studies of the La₂O₃- ZnO nanomaterials, respectively. The results obtained from previous techniques support ZnO's growth from crystalline to nanoparticles' fine structure by changing the concentrations of lanthanum oxide (La₂O₃) dopants in the host matrix. The percentage of ZnO doped with La- influences the ZnO photocatalytic activity. SEM analysis confirmed the grain size ranged between 81 and 138 nm. Furthermore, UV-Vis diffuse reflectance spectroscopy was performed to verify the effects of La₂O₃ dopants on the linear optical properties of the nano-composite oxides. There was a variation in the energy bandgaps of La₂O₃-ZnO nanocomposites, increasing the weight concentrations of lanthanum dopants. The AC electrical conductivity, dielectric properties, and current-voltage properties support the enactment of the electrical characteristics of the ZnO nanoparticles by adding La₂O₃. All the samples under investigation were used for photodegradation with Rhodamine B (RhB) and Methylene Blue (MB). In less than 30 min of visible light irradiation, S4 (0.5 g) La₂O₃-ZnO reached 99% of RhB and MB degradation activity. This study showed the best photocatalytic effect for RhB and MB degradation of 0.13 and 0.11 min^-1 by 0.5 g La₂O₃-ZnO. Recycling was performed five times for the nanocatalysts that displayed up to 98 percent catalytic efficiency for RhB and MB degradation in 30 min. The prepared La₂O₃-ZnO nanostructured composites are considered novel candidates for various applications in biomedical and photocatalytic studies.

Keywords: La2O3-ZnO nanostructured composites; combustion method; electrical conductivity/electrical properties; optical band gap; photocatalytic activity; structural properties; varistors.

Grants and funding

The author from KKU extend his appreciation to the research center for advance materials science (RCAMS), King Khalid University for funding this work under grant number RCAMS/KKU/G014-21.