Browsing by Author "Sunday W. Balogun"

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    Evaluation of Environmentally Friendly Zinc Oxide Nanoparticles Synthesized Using Carica papaya Leaf Extract for Renewable Energy Applications
    (IRAQI JOURNAL OF APPLIED PHYSICS, 2026-01-01) Sunday W. Balogun; Hakeem O. Oyeshola; Sefiu A. Bello; Hope K. Adewumi; Yekinni K. Sanusi
    This research explores the green synthesis of zinc oxide nanoparticles using Carica papaya leaf extract as a reducing agent. With a focus on developing reliable, eco-friendly, and cost-effective nanomaterial for device technologies, this sustainable method offers an alternative to conventional bulk material synthesis. Synthesized powder samples were characterized using XRD, FTIR, UV-Vis spectroscopy, SEM, EDX, and TEM. Spin-coating technique was used for thin-film deposition, while current-voltage properties were measured using a four-point probe system connected to a Keithley 2400 measurement unit and a solar simulator. Absorption peaks ranged from 299-382 nm as recorded from UV-visible, which is inferior to bulk material at 410 nm. The band gap energy was estimated to be 3.47 eV, resistance 5192.63 Ω, resistivity 132.0038 Ωm⁻¹, and conductivity 7.6×10⁻³ Sm⁻¹ were determined. These results highlight ZnO nanoparticles potential for renewable energy and semiconductor applications
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    Optical, morphological, and structural properties of green-synthesized zinc oxide nanoparticles as a promising nanomaterial for integration in solar cells
    (KWASU PRESS AND PUBLISHING, 2026-06-30) Sunday W. Balogun; Sefiu Adekunle Bello; Akeem Sodiq Olalekan
    Green - synthesized method for the production of metal oxide nanoparticle for energy conversion has received attraction over physical and chemical routes of synthesis due to its eco-friendliness, energy efficiency, and nontoxicity. Nanotechnology promotes large-scale production of materials for energy conversion, electronics, and optoelectronics. Research on biosynthesis of nanoparticles remains an inexhaustible field. This paper presents bio-synthesis of zinc oxide nanoparticle (ZnONPs) for integration in solar cells from Zinc nitrate hexahydrate using Moringa oleifera extract as capping and reducing agent. Analyses of zinc oxide nanoparticles’ structural, optical, surface morphological, elemental composition, and chemical bond properties were conducted. The SEM analysis indicate a spherical, nanosized grain morphology with a diameter of 36.25 nm. The XRD analysis yielded an average crystallite size diameter of approximately 36.28 nm. XRD result revealed the wurtzite hexagonal nature of ZnO and showed that temperature annealing affects crystallite grain size. FT-IR spectroscopy confirmed formation of zinc oxide nanoparticles. Optical spectroscopic analysis showed that ZnO nanoparticles properties were influenced by temperature annealing. The band gap varies from 1.1 eV to 1.22 eV, which decreases with increase in annealing temperature. These findings elucidate the potential of extract from Moringa oleifera plant as a green source of capping agent for ZnO-NPs synthesis. The study establishes Moringa oleifera leaf extract as an efficient, eco-friendly precursor for ZnO NP synthesis. The results, also demonstrated the possibility of thermal annealing as a means of tunning ZnO nanoparticles properties. Overall, the potential embedded in these results suggest ZnO nanoparticles as a promising suitable nanomaterial for solar cell photo-anodes.
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    Sustainable Materials from Wastes for Engineering Applications
    (Nigerian Institution of Metallurgical, Mining and Materials Engineers (A Division of The Nigerian Society of Engineers), 2025-06-25) Sefiu Adekunle Bello; Abdul Ganiyu Funsho Alabi; Sunday W. Balogun; Mohammed Kayode Adebayo; Suleiman Danjuma Daudu; Aisha Mayowa Akintola; Karimat Aderoju Saba
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    Theoretical studies of the suitability of imidazolypyridine as bidentate ligands for copper redox couples in the Dye Sensitized Solar Cell (DSSC) application
    (Research Square, 2025-12-19) Wahab Osunniran; Abdullateef Salaudeen; Bolatito E. Olanipekun; Sunday W. Balogun; Sikiru Ahmed; Olusola O. James
    Copper complex redox couples have emerged as alternative redox mediator to iodide/triiodide redox couple for DSSC devices. The copper redox couples enable high and tunable voltage in DSSC devices. However, the Cu(II) species in a typical copper redox couples are strongly electrophilic towards injected electrons in TiO2 thereby promoting recombination and decreases the cell performance. Although 4-tertbutylpyridine (TBP) passivation of TiO2 surface reduces the extent of the recombination, its interaction with Cu(I) complex in a copper redox couples may be detrimental to the cell performance. Therefore, rational selection of ligands of the copper complexes is critical in obtaining high voltage and performance. In this work, Density Functional Theory (DFT) was adopted to screen four imidazoly-pyridine bidentate ligands: 2-(1-methyl-4,5- dihydro-1H-imidazol-2-yl)pyridine (MDIP); 2-(1-methyl-1H-imidazol-2-yl)pyridine (MIP); 2- (1,4,5-trimethyl-1H-imidazol-2-yl)pyridine (TMIP) and 1-methyl-2-(pyridin-2-yl)-1Hbenzo[ d]imidazole (MPBI). Calculated binding constants of interaction of 4-tertbutylpyridine (TBP) with the imidazoly-pyridine copper complexes indicated Cu(I) complexes of MDIP and MIP interact strongly with TBP. This has adverse effects on device voltage, thus, making MDIP and MIP ligand unsuitable. But Cu(I) complexes of TMIP and MPBI interact very weakly with TBP, indicating they are suitable ligands for copper complex redox couples for DSSC application