Browsing by Author "Korucu H."

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    Cost-effective chemical solution synthesis of bismuth telluride nanostructure for thermoelectric applications
    (Institution of Engineering and Technology, 2018) Mamur H.; Dilmac O.F.; Korucu H.; Bhuiyan M.R.A.
    In this work, the bismuth telluride (Bi2Te3) nanostructure for thermoelectric applications was successfully synthesised by a new cost-effective chemical solution process. Firstly, the metal solutions of bismuth (III) nitrate pentahydrate and tellurium dioxide were mixed together at room temperature with adjusting the hydrodynamic atmosphere and introduced the sodium hydroxide. After that, different characterisation parameters, such as X-ray diffraction, atomic force microscopy (AFM), scanning electron microscopy (SEM), energy dispersive X-ray, and transverse electron microscopy (TEM) were obtained. Then, the average crystalline size of the Bi2Te3 nanostructure was found 23 nm. According to these obtained results, the materials consist of every specimen in nano range dimension in AFM studies. The elemental of Bi and Te were arranged with their quite stoichiometric atomic ratio observed by SEM. Ultimately, the TEM micrographs showed that the powders exhibited an aggregate phenomenon, and the primary crystalline size was about low dimension. © 2018 Institution of Engineering and Technology. All rights reserved.
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    Growth and characterization of Bi2Te2.70Se0.30 nanostructured materials by using a cost-effective chemical solution route
    (Elsevier B.V., 2023) Bhuiyan M.R.A.; Korucu H.; Mamur H.; Haque M.M.
    A chemical solution route was employed to successfully synthesize single-phase Bi2Te2.70Se0.30 nanostructured powders at room temperature, ensuring minimal contamination. The synthesized powders underwent a comprehensive analysis using a range of characterization techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDAX), ultraviolet-visible (UV) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, atomic-force microscopy (AFM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The temperature-dependent behaviors of electrical conductivity and the Seebeck coefficient were also explored. The findings revealed that the synthesized powders displayed consistent spherical morphology, with an average diameter of 68.42 nm. Additionally, they exhibited a band gap energy of 0.615 eV. This research highlights the significant improvement achieved by incorporating selenium into the Bi2Te2.70Se0.30 materials through this synthesis process. The EDAX analysis confirmed the stoichiometric atomic ratio of bismuth (Bi), tellurium (Te), and selenium (Se) elements. Furthermore, the TEM images revealed the presence of agglomeration within the powders, demonstrating a primary crystalline size characterized by relatively small dimensions. The emergence of a pronounced exothermic peak at around 650 K signaled the commencement of oxidation for the Bi2Te2.70Se0.30 material. In electrical measurement, a synergy was achieved between heightened electrical conductivity and a well-matched Seebeck coefficient, with the goal of enhancing energy conversion efficiency in TE applications. These findings demonstrate the potential of the synthesized powders for producing nanostructured thermoelectric (TE) materials with controlled grain sizes, which are essential for the fabrication of high-performance thermoelectric generators (TEGs). © 2023 The Authors
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    Emerging Opportunities and Challenges of Nanoparticles in Nanomedicine
    (Gazi Universitesi, 2024) Bhuiyan M.R.A.; Mamur H.; Ustuner M.A.; Korucu H.
    Nanomedicine encompasses a wide range of utilizations, including medical biological devices, nanoparticles (NPs), nanoelectronic biosensors, and possible future applications of molecular nanotechnologies, such as biological machines. Understanding toxicity and environmental impact problems is a current challenge in nanomedicine. The advancement of NPs in nanomedicine foresees emerging opportunities that may change healthcare by enhancing pharmaceutical effectiveness. This review may reveal novel and improved biomedical significance by delving deeper into advanced growth methodologies and NP applications in nanomedicine. NPs' outstanding physical and chemical characteristics have advanced medical, diagnostic, and screening techniques. The present review offers a current overview of organic and inorganic nanoparticles, highlighting recent advancements, obstacles, and potential applications for nanomedicine. Also, the focus of this review is on a fundamental concept that underlies the creation of novel and successful therapies using NPs in the field of nanomedicine for the human body's lungs, heart, brain, and kidneys. This extensive and insightful information source would be beneficial to the advancement of nanomedicine. © 2024, Gazi Universitesi. All rights reserved.
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    Influence of Leg Geometry on the Performance of Bi2Te3 Thermoelectric Generators
    (Gazi Universitesi, 2024) Hasan M.K.; Ustuner M.A.; Korucu H.; Bhuiyan M.R.A.; Mamur H.
    This study analyzed the significant performance using COMSOL Multiphysics software of thermoelectric modules (TEMs) fabricated from aluminium oxide (Al2O3), copper (Cu), and bismuth telluride (Bi2Te3) materials, with a particular focus on investigating various leg geometries. The TEM design had Al2O3 for insulation, Cu for conducting, and Bi2Te3 for TE legs among the Cu. Investigated the influence of square and rectangular TE legs with heights of 2.0, 2.75, and 3.5 mm on critical parameters such as the normalized current density, electric potential, temperature gradient, and total internal energy within the TEM. Furthermore, the impact of varying thicknesses in the insulator and conductor layers of the TEM was explored. The results consistently demonstrated that the square leg geometry, particularly when configured with a height of 2.75 mm, outperformed other leg geometries. Consequently, it is suggested to adopt a square-shaped Bi2Te3 TEM measuring 1 mm × 1 mm × 2.75 mm with a 0.50 mm Al2O3 thickness and 0.125 mm Cu thickness during the manufacturing process. Investigate how temperature differences in TE device leg design are influenced by parameters such as the Seebeck coefficient (S), thermal conductivity (k), and electrical conductivity (σ). At lower temperatures, modeling reveals lower electrical conductivity and enhanced thermal conductivity, highlighting the significance of S = ± 2.37×10⁻⁴ V/K. This illustrates the high potential of TEM for applications in thermoelectric generator (TEG) manufacturing. © 2024, Gazi Universitesi. All rights reserved.