İnşaat TeknolojisiConstructiom Technologyhttps://hdl.handle.net/20.500.12511/2132024-03-28T16:53:30Z2024-03-28T16:53:30ZSynthesis of CuBDC metal-organic framework supported zinc oxide via ball-milling technique for enhanced adsorption of Orange-IIYardımcı, BatuhanKanmaz, NergizBuğdaycı, MehmetDemirçivi, Pelinhttps://hdl.handle.net/20.500.12511/123782024-03-20T06:31:25Z2024-01-01T00:00:00ZSynthesis of CuBDC metal-organic framework supported zinc oxide via ball-milling technique for enhanced adsorption of Orange-II
Yardımcı, Batuhan; Kanmaz, Nergiz; Buğdaycı, Mehmet; Demirçivi, Pelin
For the first time, copper-based metal-organic framework (CuBDC) supported ZnO composite was successfully prepared by the ball-milling method for effective adsorption of anionic azo orange-II (OII) dye. After comparing the OII adsorption performances of ZnO and composites, with two different CuBDC support ratios, focused on the investigation of 1:1 CuBDC@ZnO. The crystal structures, physicochemical properties, and surface morphologies of the adsorbents were characterized by XRD, FTIR, SEM-EDX, and BET analyses. The adsorption process fitted the Langmuir isotherm model (R2=0.98) and the monolayer adsorption capacity of 1:1 CuBDC@ZnO composite was found to be 132.12 mg g−1. The adsorption process was well described by the pseudo-second-order model, which indicates the adsorption process of 1:1 CuBDC@ZnO composite on OII is chemisorption. Moreover, 1:1 CuBDC@ZnO composite can be an alternative as an effective and innovative adsorbent for the removal of toxic OII dye contaminant.
2024-01-01T00:00:00ZThermodynamic analysis of production parameters and microstructural evolution in shape memory Ni(50-x)Ti(50)Fe(x) (x = 5, 10) alloy synthesized by combustion synthesisKeskin, BerkDerin, Borahttps://hdl.handle.net/20.500.12511/123452024-03-08T06:05:24Z2024-01-01T00:00:00ZThermodynamic analysis of production parameters and microstructural evolution in shape memory Ni(50-x)Ti(50)Fe(x) (x = 5, 10) alloy synthesized by combustion synthesis
Keskin, Berk; Derin, Bora
This study represents an initial effort to produce NiTiFe shape memory alloys via the self-propagating high-temperature synthesis (SHS) process. The synthesis successfully yielded Ni45Ti50Fe5 and Ni40Ti50Fe10 alloys from elemental Ni, Ti, and Fe powders at three distinct preheating temperatures (240, 330, 420 °C). To support empirical findings, thermodynamic analysis using Factsage Thermodynamic Software was employed to correlate reaction propagation behavior with chemical composition. The calculation showed that the addition of 5 at.% Fe to the B2 phase did not hinder reaction self-propagation. This conclusion was supported with the ∆Hf/Cp ratio and transient liquid ratio, computed using the sub-lattice model, which closely resembled that of NiTi. Whereas 10 at.% Fe that synthesized at preheating temperature of 240 °C exhibits struggle, thus an increase in triggering time causes an effect on crystallite size and a decrease in porosity. Empirical results confirmed these findings, albeit influenced by ignition times. An increase in the liquid ratio due to the adiabatic temperature rise can also result in a reduction of NiTi content when the Fe ratio is increased, consequently diminishing the driving force for the reaction. In the sample containing – 5% Fe, the main phase is B2, and the R martensitic phase is also present. Ms is determined to be – 38.7 °C. SEM analyses revealed the presence of Ti2Ni and Ti2Ni3 phases in the upper and lower regions, while the distribution in the middle section is more homogeneous. No martensitic transformation was observed in 10% Fe. Additionally, nanocrystalline regions were detected within the samples by transmission electron microscopy, contributing to a nuanced understanding of their structural properties. Graphic abstract: (Figure presented.).
2024-01-01T00:00:00ZVacuum carbothermal synthesis of TiB2Buğdaycı, MehmetGüleç, Şeymahttps://hdl.handle.net/20.500.12511/118802024-01-04T05:48:39Z2023-01-01T00:00:00ZVacuum carbothermal synthesis of TiB2
Buğdaycı, Mehmet; Güleç, Şeyma
Abstract: In this study, the formation conditions of TiB2, whose main production method is carbothermal reduction, at lower temperatures with additional processes (vacuum, mechanical activation and functional addition effect) were investigated. In this study, firstly the 100% stoichiometric mixture was reduced at 1200°C under vacuum for varying experimental durations. Afterwards, the effect of mechanical activation amount on TiB2 formation was determined by keeping the 4-h reduction time, which was determined as optimum in the first set of experiments. At the last stage of the experiments, the addition of 2.5 and 5% NaCl effect on the mixtures in the first set of experiments was determined. The samples obtained after the experiment were characterized by XRD and SEM techniques, and it was observed that the undesired phases were completely removed as a result of the reduction performed after 16 h of ball mile operation, and this experiment was determined as the optimum experimental condition.
2023-01-01T00:00:00ZPromoting photo-fenton catalytic performance of novel NiZrO3-type perovskite: Optimization with response surface methodologyKanmaz, NergizBuğdaycı, Mehmethttps://hdl.handle.net/20.500.12511/115332023-11-15T08:00:37Z2024-01-01T00:00:00ZPromoting photo-fenton catalytic performance of novel NiZrO3-type perovskite: Optimization with response surface methodology
Kanmaz, Nergiz; Buğdaycı, Mehmet
Perovskite type NiZrO3 photocatalysts were synthesized by ball-mill technique and used for tetracycline (TC) degradation. NiZrO3 milled for 6 h (NiZrO3-6h) had significant-99 % photo-Fenton catalytic activity on TC removal It was determined that the characteristic peaks of NiZrO3 with XRD, spherical shaped structures with SEM, no organic peaks in the structure with FTIR, band gap of 4.40 eV with DRS and stable colloids with zeta potential. Response surface methodology (RSM) including Box-Behnken design (BBD) was applied to examine H2O2, Fe2+ and initial TC concentration effects on degradation and it was observed that H2O2 concentration had the highest effect on TC degradation. The photocatalytic efficacy of NiZrO3 could still eliminate 78 % of initial antibiotic molecules after eight-cycle. The application potential for Photo-Fenton assisted NiZrO3-6h was also observed in the degradation of other organic pollutants such as drugs (salicylic acid, ciprofloxacin, ampicillin) and dye (methylene blue, rhodamine-b, orange-II, malachite green, crystal violet). It suggests that the mechanochemically synthesized NiZrO3-6h perovskite could be suitable for its effective use in the photo-Fenton catalytic system.
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