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Öğe A promising nanocatalyst: Upgraded Kraft lignin by titania and palladium nanoparticles for organic dyes reduction(Elsevier B.V., 2021) Nezafat, Zehra; Mohazzab, Bahareh Feizi; Jaleh, Babak; Nasrollahzadeh, Mahmoud; Baran, Talat; Shokouhimehr, MohammadrezaThe evaluation of dye degradation was adorned a great interest due to scarcity of water, courtesy of industrialization. Here, Kraft lignin was upgraded by immobilization of TiO2 nanoparticles (NPs) by the reflux method (KL-T). Palladium (Pd) NPs were produced in a promising way by laser ablation in liquid (LAL) and loaded on KL-T to prepare an efficient nanocatalyst (KL-T/Pd). The synthesized KL-T/Pd is characterized by X-ray diffraction (XRD), Fourier transforms infrared (FT-IR), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectrometry (EDX), and Transmission electron microscope (TEM) analyses. The KL-T/Pd nanocomposite was applied as an efficient and novel nanocatalyst for the reduction of methylene blue (MB) and methyl orange (MO) by NaBH4 as a reducing agent in aqueous media at ambient temperature. Our experimental results displayed that the 1 mg of KL-T/Pd catalyst can be reduced MB and MO organic dyes within 23 and 8 s, respectively at room temperature. The KL-T/Pd nanocatalyst can be recycled and reused four times with no considerable loss of performance. Having different advantages such as high catalytic performance, safe synthesis method, and high stability, lignin was suggested as a natural substrate.Öğe Bentonite-supported furfural-based Schiff base palladium nanoparticles: an efficient catalyst in treatment of water/wastewater pollutants(Springer, 2020) Nasrollahzadeh, Mahmoud; Baran, Talat; Sajjadi, Mohaddeseh; Yılmaz Baran, Nuray; Shokouhimehr, MohammadrezaThis study reports a versatile process for the fabrication of palladium nanoparticles (Pd NPs) stabilized on Schiff base modified Unye bentonite with a coordination performance of furfural ligand (UN-Fur@PdNPs) as a promising nanocatalyst in the reduction of organic/inorganic pollutants. APTES ((3-aminopropyl)triethoxysilane)-modified UN-Fur@PdNPs has been synthesized via a facile, multi-step procedure without any additional stabilizing/reducing agents. The characterization of UN-Fur@PdNPs sample was carried out by FTIR, XRD, EDS, elemental mapping, STEM, TEM, HRTEM, and TG/DTG analyses which indicate the formation of Pd NPs (~ 10 nm) on the surface of UN-Fur. The catalytic activity/stability of the as-prepared nanocatalyst has also been assessed in the reduction of 4-nitrophenol (4-NP), Congo Red (CR), Methylene Blue (MB), and Methyl Orange (MO) dyes by NaBH4 (sodium borohydride) and chromium [Cr(VI)] by HCOOH (formic acid) in water. Catalytic efficiency retention has also been obtained after eight cycles. UN-Fur@PdNPs showed excellent catalytic performance and high stability/sustainability in the reduction of all five targeted organic/inorganic pollutants.Öğe Facile synthesis of Pd nanoparticles supported on a novel Schiff base modified chitosan-kaolin: Antibacterial and catalytic activities in Sonogashira coupling reaction(Elsevier B.V., 2021) Nasrollahzadeh, Mahmoud; Shafiei, Nasrin; Baran, Talat; Pakzad, Khatereh; Tahsili, Mohammad Reza; Yılmaz Baran, Nuray; Shokouhimehr, MohammadrezaThe present work studies the Sonogashira coupling reaction (SCR) between aryl halides and acetylenes under aerobic conditions using the catalytic complex of Pd nanoparticles (NPs) supported on a novel Schiff base modified chitosan-kaolin (Pd NPs@CS-Kao) in ethanol solvent. The prepared catalyst was characterized by TEM, SEM, FT-IR, XRD, EDS, XPS, elemental mapping, and Raman analyses. The products were formed in high yields. At the end of the reaction, Pd NPs@CS-Kao can be filtered and reused for five consecutive cycles. The advantages of this catalytic process include simple methodology, high yields, and easy work-up. In addition, Pd NPs@CS-Kao exhibited effective antibacterial performance against E. coli gram-negative bacteria.Öğe Modified chitosan-zeolite supported Pd nanoparticles: A reusable catalyst for the synthesis of 5-substituted-1H-tetrazoles from aryl halides(Elsevier B.V., 2022) Sajjadi, Mohaddeseh; Nasrollahzadeh, Mahmoud; Ghafuri, Hossein; Baran, Talat; Baran, Nuray Yılmaz; Orooji, Yasin; Shokouhimehr, MohammadrezaA novel heterogeneous catalyst has been developed using chitosan-zeolite supported Pd nanoparticles (PdNPs@CS-Zeo) and used in an efficient synthesis of 5-substituted-1H-tetrazoles from aryl halides with high yields for relatively short reaction times with an easy work-up procedure. In this method, highly effective and reusable PdNPs@CS-Zeo catalyst was used in the reaction of various aryl iodides/bromides with K4[Fe(CN)6] as a non-toxic cyanide source to catalyze the [2 + 3] cycloaddition of the corresponding aryl nitriles with NaN3 in the sequential one-pot preparation of 5-substituted-1H-tetrazoles. The synthesized PdNPs@CS-Zeo nanocatalyst was characterized using XRD, FTIR, TEM, HRTEM, XPS, Raman, TG-DTG, ICP-OES, BET, and EDS mapping. Additionally, the nanocatalyst could be effectively separated by filtration and reused for multiple times without significant decrease of catalytic activity.Öğe Palladium nanoparticles stabilized on a novel Schiff base modified Unye bentonite: Highly stable, reusable and efficient nanocatalyst for treating wastewater contaminants and inactivating pathogenic microbes(Elsevier B.V., 2020) Sajjadi, Mohaddeseh; Baran, Nuray Yılmaz; Baran, Talat; Nasrollahzadeh, Mahmoud; Tahsili, Mohammadreza; Shokouhimehr, MohammadrezaEfficient decoration and characterization of highly catalytic, active Pd nanoparticles (NPs) onto a novel Schiff base modified Unye bentonite (UN-Sch) with high coordination performance of structurally defined 2-pyrrolaldehyde ligands against palladium ions (Pd NPs@UN) have been described. Amine modified UN/Pd NPs were fabricated via a facile multi-step approach without utilizing any additional reducing agents. To check the applicability of the synthesized Pd NPs@UN as highly active nanocatalysts in water and wastewater treatment, the reduction of highly toxic compounds such as 4-nitrophenol (4-NP), hexavalent chromium [Cr(VI)], Rhodamine B (RhB), potassium hexacyanoferrate(III) (K3[Fe(CN)6]) and congo red (CR) at ambient temperature in eco-friendly media has been investigated. The surface nature of Unye bentonite was altered after modification, leading to notable increase in the catalytic properties. The ensuing Pd NPs@UN demonstrated superior catalytic prowess (100% conversion within a few seconds for the aforementioned pollutants), excellent stability (~4 months) and superior recyclability (~96% yield after seven successive cycles). Notably, the present procedure is a clean and green one in which aqueous sodium borohydride (NaBH4) or formic acid (HCOOH) are used as reducing agents in the absence of any toxic reductants. Moreover, the results showed that Pd NPs@UN was effective against fungi and bacteria.Öğe Pd nanocatalyst stabilized on amine-modified zeolite: Antibacterial and catalytic activities for environmental pollution remediation in aqueous medium(Elsevier B.V., 2020) Nasrollahzadeh, Mahmoud; Baran, Talat; Baran, Nuray Yılmaz; Sajjadi, Mohaddeseh; Tahsili, Mohammadreza; Shokouhimehr, MohammadrezaIn this study, the immobilization of palladium nanoparticles (NPs) on amine modified zeolite (Zeo) particles bearing a heterocyclic ligand has been developed through immobilizing structurally defined furfural with long tail of 3-aminopropyltriethoxysilane. NH2 modified Zeo/Pd has been synthesized via facile multi-step organic amine functionalization as a sustainable, recoverable and highly active nanocatalyst in the reduction of hexavalent chromium [Cr(VI)], potassium hexacyanoferrate(III) (K3[Fe(CN)6]), 2,4-dinitrophenylhydrazine (2,4-DNPH), 4-nitrophenol (4-NP), Rhodamine B (RhB), Methylene Blue (MB) and Nigrosin (NS) at ambient temperature in aqueous media. The surface nature of zeolite was changed after NH2 modification, leading to a remarkable increase in the catalytic and antimicrobial performances. TEM and HRTEM (high resolution transmission electron microscopy), FESEM (field emission scanning electron microscopy), STEM (scanning transmission electron microscopy), TG-DTG (thermogravimetry/derivative thermogravimetry), FT-IR (Fourier transform infrared), XRD (X-ray diffraction), EDS (energy dispersive X-ray spectroscopy), elemental mapping, XPS (X-ray photoelectron spectroscopy) and Raman analyses have been used to characterize the as-prepared nanocatalyst. The high removal rates of these environmental pollutants with NH2 modified Zeo/Pd nanocatalyst (Pd NPs@Zeo) using sodium borohydride (NaBH4) and formic acid (HCOOH) at ambient temperature were measured via UV–Vis spectroscopy and the nanocatalyst could be reused at least eight times without any significant loss of catalytic activity.Öğe Pd nanoparticles loaded on modified chitosan-Unye bentonite microcapsules: A reusable nanocatalyst for Sonogashira coupling reaction(Elsevier Ltd, 2021) Shafiei, Nasrin; Nasrollahzadeh, Mahmoud; Baran, Talat; Yılmaz Baran, Nuray; Shokouhimehr, MohammadrezaThis work investigates the preparation of a catalytic complex of palladium nanoparticles supported on novel Schiff base modified chitosan-Unye bentonite microcapsules (Pd NPs@CS-UN). The complex has been characterized by FT-IR, EDS, XRD, TEM, HRTEM, Raman, ICP-OES and elemental mapping analyses. Pd NPs@CS-UN was used as a catalyst for Sonogashira coupling reactions between aryl halides and acetylenes, employing K2CO3 as the base and EtOH as a green solvent under aerobic conditions in which it showed high efficacy. Pd NPs@CS-UN was regenerated by filtration after the completion of the reaction. This catalytic process has many advantages including simple methodology, high yields, and easy work-up. The catalytic performance does not notably change even after five consecutive runs.
