Browsing by Author "ERDEM, BEYHAN"

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Adsorption of light green and brilliant yellow anionic dyes using amino functionalized magnetic silica (Fe 3 O 4 @SiO 2 @NH 2) nanocomposite
(Taylor, 2019-01-01) Erdem, Beyhan; Avşar, Saliha Buşra; Erdem, Sezer; Tekin, Nalan; ERDEM, BEYHAN; Avşar, Saliha Buşra; ERDEM, SEZER; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Kimya Bölümü; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü; AAI-1238-2021; AAI-1248-2021; CDX-3142-2022
Fe3O4@SiO2@NH2 nanocomposite was prepared for highly effective adsorption of two anionic dyes one of which is triarylmethane dye (light green, LG) and the other is azo dye (brilliant yellow, BY). The characterization results demonstrated that superparamagnetic Fe3O4 nanoparticles were covered with silica and functionalized with amino groups successfully without losing magnetic character. The effects of adsorbent dosage, contact time, pH, temperature, and dye molecular structure on the adsorption were investigated. Acidic pH was better for both LG and BY, on the other hand, alkaline pH was favorable to some extent for LG in comparison with BY due to the contribution of stacking effect in addition to electrostatic attraction. Kinetic data demonstrated that the driving force for adsorption process could be explained by pseudo-second order mechanism in both systems. The equilibrium data were more compatible with Langmuir isotherm than those of Freundlich isotherm and the maximum adsorption capacities of Fe3O4@SiO2@NH2 calculated from Langmuir isotherm model for LG and BY at 30 degrees C and natural pH of the solution were 40.2 and 35.5 mg g(-1). Thermodynamic calculations related to temperature dependence demonstrated that the adsorption process was spontaneous and exothermic.
Cationic surfactant templated synthesis of magnetic mesoporous nanocomposites for efficient removal of Light Green
(Korean Institute Chemical Engineers, 2021-06-22) Erdem, Beyhan; Erdem, Sezer; Tekin, Nalan; ERDEM, BEYHAN; ERDEM, SEZER; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Kimya Bölümü; AAI-1238-2021; AAI-1248-2021
Fe3O4-SiO2-NH2, Fe3O4-CTABSiO(2)-NH2 and Fe3O4-SiO2-CTABSiO(2)-NH2 magnetic adsorbents were successfully prepared and could be used effectively for the adsorption of Light Green from aqueous solutions. Unlike the first sample, mesoporous silica coatings were created using cetyltrimethylammoniumbromide micelles as molecular templates on superparamagnetic iron oxide in one sample, and on silica-coated iron oxide in the other sample to improve the adsorptive properties of the nanocomposites. The characterization by FT-IR, SEM/EDX, Zeta-potential, XRD, VSM, and N-2-adsorption/desorption confirmed the production of mesoporous silica layer. Although coating processes with both silica and mesoporous silica layers led to a vaguely decrease in saturation magnetization of the Fe3O4-SiO2-CTABSiO(2)-NH2, the nanoparticles were protected with silica coatings for environment conditions and made more suitable for subsequent amino functionalization. The results determined from Batch adsorption experiments fitted to Langmuir isotherm model with maximum adsorption capacity (q(max)) equal to 56.18, 196.08 and 227.27 mg g(-1), for Fe3O4-SiO2-NH2, Fe3O4-CTABSiO(2)-NH2 and Fe3O4-SiO2-CTABSiO(2)-NH2, respectively, and it was seen from the kinetic results, the LG adsorption was identified by pseudo-second-order kinetics, revealing that LG adsorption process is homogeneous, monolayer and based on chemical interactions. According to the results, both silica and mesoporous silica coating strategy can play crucial role in improving the adsorptive properties of nanocomposites.
Comparative influence of adsorption assisted magnetic mesoporous TiO2 photocatalyst for the removal of methylene blue and rhodamine B
(Springer, 2023-04-01) Öksüzoğlu, Ramis Mustafa; Erdem, Beyhan; ERDEM, SEZER; ERDEM, BEYHAN; Erdem, Sezer; Sevinç, Samet; Bursa Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Kimya Bölümü.; Bursa Uludağ Üniversitesi/Fen Edebiyat Fakültesi/Fizik Bölümü.; 0000-0002-0574-5170; ABB-3036-2021
In this study, magnetically separable Fe3O4-SiO2-mesoTiO(2) nanocomposite has been synthesized for photodegradation of Methylene Blue (MB) and Rhodamine B (RhB) cationic dyes which have complex aromatic structures and are difficult to degrade into harmless products. By XRD analysis, it was determined that the magnetite phase of Fe3O4 was protected after coating with SiO2 interlayer and mesoTiO(2) shell, and the anatase phase of TiO2 was formed. According to the N-2-adsorption/desorption and VSM results, Fe3O4-SiO2-mesoTiO(2) nanocomposite has a surface area of 197.8 m(2)/g, pore volume of 0.34 cm(3)/g and a pore size of 3.4 nm and has 3.8 emu/g saturation magnetization and negligible remnant magnetization and coercivity, which indicates its mesoporous and superparamagnetic character. The adsorption ability of RhB (16.86%) is lower than MB (23.32%), nevertheless, the photodegradation activity of RhB (99.06%) is higher than that of MB (97.52%). Photodegradation kinetics follows the pseudo-first order and the rate constants of photocatalytic reactions were calculated as 0.0422 and 0.0719 min(-1) for MB and RhB, respectively. While the lower adsorption feature of RhB was resulted from steric hindrance, the higher photodegradation rate was explained by more radical scavenging effect. MB prefers to face the photocatalyst surface, whereas RhB prefers to focus on the aqueous phase, and based on scavenge results, RhB is more likely to encounter photoactive species (H2O2, h(+) and center dot O-2(-)) than that of MB with center dot O-2(-) being the dominant active species. The synthesized Fe3O4-SiO2-mesoTiO(2) photocatalyst could be reused three times with negligible photocatalytic loss in the photodegradation of both dyes.
Effect of calcination temperature on the structural and magnetic properties of Ni/SBA-15 nanocomposite
(Springer, 2015-06-01) Erdem, Sezer; Erdem, Beyhan; Öksüzoğlu, Ramis Mustafa; Çitak, Alime; ERDEM, SEZER; ERDEM, BEYHAN; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Fizik Bölümü; Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Kimya Bölümü; AAI-1238-2021; AAI-1248-2021
The effect of calcination temperature on the structural and magnetic properties of Ni/SBA-15 nanocomposite prepared by reductant-impregnation method was studied using SBA-15 mesoporous silica as support. The structure, morphology and magnetic properties of the samples were characterized using X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectrometry, N-2 adsorption/desorption (BET and BJH), vibrating sample magnetometer, and FT-IR. Characterization results showed the presence of crystalline phases characteristics of the Ni and/or NiO, and that the structural characteristics of the support were maintained after the impregnation of nickel ions followed by calcinations. Calcination process helps in crystallization and formation of the desired phase such as well crystalline NiO and Ni nano-particles. Moreover, this heat resulted in significant effects on different properties of the products such as the crystallite size, homogeneity, particle distribution, porosity, surface area and the sintering process. Magnetic measurements suggested that the magnetic properties in nanocomposites is probably the sum of two contributions: superparamagnetic and ferromagnetic one depending on the calcination temperature. Calcination at high temperatures affects both of the structural and magnetic properties of Ni/SBA-15. Because the location of the Ni particles depends on the pore size of the support, the uniformity of particle size was related to the interaction between the Ni particles and support.
Multifunctional magnetic mesoporous nanocomposites towards multiple applications in dye and oil adsorption
(Springer, 2021-04-09) Erdem, Beyhan; İşcan, Kübra Bilgin; ERDEM, BEYHAN; İşcan, Kübra Bilgin; Bursa Uludağ Üniversitesi/Fen-Edebiyat Fakültesi/Kimya Bölümü; 0000-0001-6765-8227; AAI-1238-2021; FDK-4016-2022
Multifunctional magnetic mesoporous nanocomposites are promising materials to remove the various pollutants from water due to the remarkable properties such as multiple binding sites, high surface area, and magnetic separation. Herein, we have developed a versatile nanocomposite, in which polydopamine (PDA) coated Fe3O4 nanoparticles are introduced during the synthesis of SBA-15 matrix for the first time to enhance adsorptive properties of hydrophilic magnetic mesoporous nanocomposite by combining the properties of high surface area, magnetization, and capability of interacting with more functional groups in one material. The resulting nanocomposite, Fe3O4@PDA@SBA-15, has been proved to be the effective sorbent for the removal of cationic dye, which can be ascribed to the functional groups of grafted PDA and the textural features of matrix SBA-15. On the other hand, after chemical modification via silanization of vinyltriethoxysilane (VTES), Fe3O4@PDA@SBA-15 nanocomposite turned to be a hydrophobic material, Fe3O4@PDA@SBA-15@VTES, which can adsorb oil with high adsorption capacity which could reach 8.83 times of its own weight. Moreover, both nanocomposites could be recycled by facile washing and drying processes. The materials provide a simple strategy for the preparation of multifunctional magnetic mesoporous nanocomposites satisfying various applications in water treatment.