Synthesis Of Palladium Nanoparticles Research Articles

Gamma radiation-assisted in situ synthesis of palladium nanoparticles supported on ethylenediamine-functionalized polypropylene fabric as an efficient catalyst for reduction of 4-nitrophenol

Immobilization of Pd nanometals on a functionalized non-woven polypropylene fabric offers heterogenous catalytic activity in many chemical transformations and convenient separation from the reaction mixture.

A simple, efficient and green approach for the synthesis of palladium nanoparticles using Oxytocin: Application for ligand free Suzuki reaction and total synthesis of aspongpyrazine A

A novel, green, eco-friendly and cost-effective biological route for the synthesis of palladium nanoparticles (PdNPs) from commercially available palladium chloride and easily isolable hormone Oxytocin as reducing agent is reported here. Characterization of PdNPs were done using various techniques, UV–visible spectroscopy, XRD, TEM and EDAX, characterization data confirmed the formation of Pd0 from Pd2+. The size of synthesized PdNPs were 15–20 nm. The scope of Pd nanoparticles was studied for the C–C bond formation Suzuki reaction. The catalytic activity of PdNPs was excellent in short reaction time and reaction works in green solvent water as well as catalyst can be recycled. Simple and efficient approach for total synthesis of aspongpyrazine A of the recently isolated natural substance is described.

Efficient synthesis of palladium nanoparticles using guar gum as stabilizer and their applications as catalyst in reduction reactions and degradation of azo dyes

AbstractPalladium is very expensive metal and has numerous applications especially as a versatile hydrogenation and dehydrogenation catalyst for chemical reactions. The main hurdle in its wide use is the high materials cost. In the present study a cost effective palladium nano catalyst was prepared using the green method of synthesis with guar gum as capping and reducing agent. The formations of palladium nanoparticles were confirmed by UV-spectrophotometer while for morphology and nature, SEM and XRD were performed that confirmed the crystalline nature of PdNPs and proved the roughly spherical shape of nanoparticles. FT-IR analysis showed different functional groups of reducing agent and proved that guar gum have the ability to stabilized as well as to reduce the Pd (II) to Pd (0). Specific signal for the palladium is present in EDX spectra that further confirmed the formation of PdNPs. The catalytic efficiency was studied using the hydrogenation of 4-nitrophenol. Rate constant of prepared nano-catalyst was 0.1436/min, its efficiency, TON, TOF, in above mention reaction is 90.83, 27.78, and 185.2/hrs, respectively. Data obtained proved synthesized PdNPs to be efficient heterogeneous catalyst for the reduction of 4-NP and for the degradation of azo dyes.

Remediation of azo-dyes based toxicity by agro-waste cotton boll peels mediated palladium nanoparticles

The present study reports an environmental benign route for the synthesis of palladium nanoparticles (Pd NPs) using agro-waste empty cotton boll peels aqueous extract for the first time. Surface Plasmon Resonance (SPR) band in absorption spectrum of Pd NPs at 275 nm confirmed the formation of Pd NPs by using UV–Vis spectroscopy. Crystalline nature of Pd NPs was confirmed by powder XRD analysis. Size and morphology was studied by transmission electron microscopy (TEM). The cotton peels extract acted as a source of phytochemicals which primarily reduced Pd+2 to Pd0 nanoparticles (Pd NPs) and imparted stability of Pd NPs by surface capping. The characteristic functional groups of phytochemicals in extract and capped Pd NPs surfaces were identified by FT-IR analysis. Catalytic activity of the synthesised Pd NPs was checked against reduction of hazardous azo-dyes such as Congo red, Methyl orange, Sunset yellow and Tartrazine with NaBH4 as electron donors. Pd NPs catalysed reduction of all azo-dyes by NaBH4 in aqueous medium was monitored by UV–visible spectroscopy where Pd NPs mediated transfer of electrons from NaBH4 to azo-dyes as carrier. The synthesized Pd NPs acted as a good catalyst and could be a promising material in degrading toxic azo-dyes from industrial effluents and wastewater.

Facile synthesis of palladium nanoparticles supported on urea-based porous organic polymers and its catalytic properties in Suzuki-Miyaura coupling

By using urea linked porous organic polymers as template, a new nano palladium catalyst with low Pd loading can be easily prepared (1.0 wt% Pd only). Although such less amount of Pd was contained in this new catalyst, it is still an effective catalyst for the Suzuki-Miyaura coupling of aryl iodines and aryl boric acids, affording biphenyl products in excellent yields with outstandingly enhanced turnover numbers (up to 10,536) under green solvent (water).

Rapid and Facile Microwave-Assisted Synthesis of Palladium Nanoparticles and Evaluation of Their Antioxidant Properties and Cytotoxic Effects Against Fibroblast-Like (HSkMC) and Human Lung Carcinoma (A549) Cell Lines.

We report here a simple microwave irradiation method (850 W, 3 min) for the synthesis of palladium nanoparticles (Pd NPs) using ascorbic acid (as reducing agent) and sodium alginate (as stabilizer agent). The synthesized nanoparticles were characterized using transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), UV-Visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) techniques. Antioxidant properties and cytotoxic effects of as-synthesized Pd NPs and Pd (II) acetate were also assessed. UV-Vis study showed the formation of Pd NPs with maximum absorption at 345 nm. From TEM analysis, it was observed that the Pd NPs had spherical shape with particle size distribution of 13-33 nm. Based on DPPH radical scavenging activity and reducing power assay, the antioxidant activities of Pd NPs were significantly higher than the Pd (II) acetate (p < 0.05). At the same concentration of 640 μg/mL, the scavenging activities were 32.9 ± 3.2% (Pd (II) acetate) and 27.2 ± 2.1% (Pd NPs). For A549 cells treated 48 h with Pd NPs, Pd (II) acetate, and cisplatin, the measured concentration necessary causing 50% cell death (IC50) was 7.2 ± 1.7 μg/mL, 32.1 ± 2.1 μg/mL, and 206.2 ± 3.5 μg/mL, respectively. On HSkMC cells, the IC50 of the Pd NPs (320 μg/mL) was higher compared to Pd (II) acetate (228.7 ± 3.6 μg/mL), which confirmed lower cytotoxicity of the Pd NPs.

Highly efficient of cross-coupling reaction supported green synthesized palladium nanoparticles coated natural ligands as heterogeneous reusable nanocatalyst

An efficient procedure and green route has been developed by using eco-friendly green synthesized palladium nanoparticles (Pd-NPs) as reusable heterogeneous nanocatalyst (Pd@nanocat) for the synthesis of diaryl ethers from the cross coupling reaction of the aryl halides with the phenol in the presence of dimethylsulfoxide (DMSO) as a solvent at 110 oC under natural ligand condition capped Pd-NPs. The generated Pd-NPs were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) techniques. Structural characterization of diaryl ether was done by nuclear magnetic resonance spectroscopy (NMR). The nanoparticles exhibited stability, reusability with excellent catalytic activity and the results of this study demonstrate the possible application of biosynthesized Pd-NPs as heterogeneous nanocatalyst in environmental remediation. Application of the cheaper base, shorter reaction time, cost-effective, high yield and environmentally friendly make our conditions potentially useful and more suitable to other reported works, which could be amenable to scale-up.

Preparation of Nanostructured Pd‐Fe2O3 Catalyst for C–C Coupling Reaction

AbstractWe have synthesized palladium nanoparticles supported iron oxide catalyst by controlled deposition of palladium in presence of triethanolamine and polyvinylpyrrolidone (PVP), where triethanolamine act as mild reducing agent and PVP act as capping agent. Prepared (0.9% Pd‐Fe2O3CD) catalyst showed high activity towards Heck coupling reaction, under mild reaction conditions. Different analytical techniques were systematically employed to characterize the prepared material in order to find the specific surface area, Pd loading, crystal structure, surface morphology, particle size, reducibility behavior, surface chemical state, phase purity and crystallinity, optical property and local environment of active species etc. 0.9% Pd‐Fe2O3CD catalyst showed high activity toward Heck coupling with iodo‐derivatives at room temperature in solvent‐free reaction conditions and prevented the leaching of active species, during catalysis. The catalyst possessed strong metal‐support interaction due to smaller Pd nanoparticles (2‐12 nm) and maintained its heterogeneous nature during recycling experiments.

Active block copolymer layer on carboxyl-functionalized PET film for hydrogen separation

To rationalize the energy requirements and environmental complications of the world, supply of pure hydrogen is the most promising as well best possible approach of such issues. Purified hydrogen gas is the necessity factor for the hydrogen-based economy. Hydrogen perm-selective membrane plays a crucial role for producing a large amount of hydrogen. Palladium is one of the best materials because of its excellent affinity to absorb hydrogen. In present work, our aim to improve selectivity as well permeability of the H2 gas compare to N2 and CO2 gases of the block copolymer coated functionalized porous PET membrane. Porous polyethylene terephthalate (PET) membranes having pore size 0.2 μm, functionalized with a carboxyl group. The supramolecular assembly was prepared from PS (35500)-b- P4VP (4400) and 2-(4- Hydroxyphenylazo) benzoic acid (HABA) in 1, 4-dioxane. Chemically synthesized palladium nanoparticles were deposited on carboxylated block copolymer (BC) coated porous PET membrane. It is an appropriate way to use H2 sensitive materials with block copolymer coated functionalized membranes to enhance the selectivity of H2. It has been found that such membranes gain better permeability and selectivity towards H2 as compared with N2 and CO2. Increment with the dipping time of these membranes in the palladium nanoparticle solution, permeability as well selectivity of H2 over N2, CO2 increases as the more attachment of Palladium nanoparticles. A fine active layer of block copolymer on the carboxyl functionalized PET membrane play a crucial role for hydrogen based gas separation. The magnitude of the permeability of such membranes for different gases shows dependency on the pore size of the upper layer (BC coated) of the membrane in addition to the molecule size of the permeating gas. Block copolymer coating of the membranes established an effective responsibility for the selectivity of H2 over CO2 gas as well over N2 gas.

Synthesis of Palladium Nanoparticles on the Surface of Cerium(IV) Oxide under the Action of Ultraviolet Radiation and Their Characterization

Palladium nanoparticles have been synthesized in an aqueous medium by ultraviolet irradiation using complex palladium oxalate as a precursor. The samples were studied by various laboratory methods, including transmission electron microscopy, X-ray fluorescence analysis, X-ray powder diffraction, X-ray absorption fine structure spectroscopy, and diffuse reflectance infrared spectroscopy with the use of CO probe molecules. The microimages obtained by transmission electron microscopy did not allow us to distinguish Pd nanoparticles from the material of the substrate but do not show any effect of ultraviolet irradiation on the sizes of CeO2 nanoparticles. The X-ray fluorescence analysis data show the presence of cerium and palladium atoms in the material. X-ray diffraction patterns indicate the presence of phases of cerium dioxide and metallic palladium, while the analysis of the X-ray absorption fine structure spectra beyond the K-edge of palladium shows the presence of the PdO phase in the system. The approximate size of the palladium nanoparticles was estimated by the infrared spectra after the adsorption of CO and is less than 2 nm, which is significantly smaller than the average size of Pd nanoparticles obtained by a similar method without a CeO2 substrate (1.5–9.5 nm).

Reducing agent free synthesis of palladium nanoparticles using Schiff base complex and study of its catalytic activity towards reduction of p-nitrophenol to p-aminophenol

A simple and facile synthesis of Palladium nanoparticles (Pd NPs) by solvothermal method using a Schiff base Pd [N,N-bis (5-chloro salicylaldehyde) o-phenylenediamine] complex without use of any reducing agent has been reported here. The as-prepared Pd NPs was further characterized by various techniques such as X-ray Diffraction (XRD), Field Emission Scanning Electron microscopy (FE-SEM), Energy dispersive X-ray (EDAX) and Transmission Electron microscopy (TEM). The catalytic activity of Pd nanoparticles was also performed toward reduction of 4-NP to 4-AP in presence of aqueous solution of NaBH4 at room temperature. This catalyst has excellent catalytic activity for reduction of 4-nitrophenol to 4-aminophenol within 9 min and has excellent reusability for three successive cycles. This enhanced catalytic activity was attributed due to formation of metallic Pd(0) nanoparticles and smaller particle size.

Evaluation of 389nm UV-LED to Induce Apoptosis in Leukemia Cells for Develop Implant Photonics-Device

There are large number of reports on the synthesis of palladium nanoparticles due to several important applications

Nanocubes of Palladium, Simple, Green Approach and Catalytic Properties Under Continuous Hydrogenation System

There are large number of reports on the synthesis of palladium nanoparticles due to several important applications

From agriculture residue to catalyst support; A green and sustainable cellulose-based dip catalyst for C[sbnd]C coupling and direct arylation

The core characteristics of a perfect catalyst include good activity, simple design, excellent stability, easy recovery from reaction mixture, recyclability, and have the provision for easy scale up. The ease in synthesis, recyclability and scale up makes the dip catalyst a major contender in this regard which possess most of the aforementioned characteristics. In this work, we report a dip catalyst made of cellulose, isolated from agriculture residue (sugarcane bagasse), in which biogenically synthesized palladium nanoparticles were dispersed. The prepared dip catalyst was characterized by FESEM, EDS, XRD, ATR-IR, TGA, TEM, XPS and ICP-OES analysis. Also, the activity of the dip catalyst was studied in the Suzuki-Miyaura cross-coupling reaction and was found to give excellent conversion with 15 recycles. Further, the activity of dip catalyst in C5-arylation of 2-substituted thiophenes was evaluated for which promising yields were obtained.

Green synthesis of palladium nanoparticles using Ananas comosus leaf extract for solid-phase photocatalytic degradation of low density polyethylene film

This paper investigated the photocatalytic potential of biosynthesized palladium nanoparticles (Pd NPs) for the degradation of low density polyethylene (LDPE). A green route synthesis of Pd NPs was carried out using Ananas comosus leaf extract (ACLE) as the reducing and stabilizing agent. The as-synthesized Pd NPs was characterized by UV–vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDX). The HRTEM image revealed that Pd NPs were well dispersed with particle size range of 1.71–16.14 nm and average particle size of 4.46 ± 2.44 nm. The XRD revealed four distinct peaks at 40.26°, 47.11°, 67.56°, and 78.09° which correspond to (111), (200), (222) and (311) planes, respectively, that can be indexed to face-centered cubic (fcc) phase of Pd NPs. Films of LDPE and its Pd NPs modified form were exposed to solar light in open air at ambient condition for increasing times of up to 30 days. The degradation of LDPE and nanocomposite LDPE films (LDPE@Pd NPs) was determined in terms of photo-induced weight loss, TEM, FTIR and thermogravimetric analysis (TGA). Thus, LDPE films with 1.0% Pd NPs showed degradation of around 49% under solar light irradiation over a short period of 30 days. The study therefore suggested the development of eco-friendly degradable plastic by utilizing the photocatalytic potential of Pd NPs, and to also serve as a possible means of addressing the growing agitations of plastic pollution in marine environment.

Facile synthesis of palladium nanoparticles immobilized on magnetic biodegradable microcapsules used as effective and recyclable catalyst in Suzuki-Miyaura reaction and p-nitrophenol reduction

This study reports (i) preparation and characterization of palladium nanoparticles (Pd NPs) stabilized on magnetically separable chitosan/agar microcapsules (Pd NPs@Fe3O4/CS-AG microcapsules) and (ii) investigation of catalytic behaviors of the prepared nanoparticles in Suzuki-Miyaura C-C cross-coupling reactions and reduction of p-nitrophenol (p-NP). Fourier transforms infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), elemental mapping, inductively coupled plasma-optical emission spectrometry (ICP-OES) and thermogravimetry/derivative thermogravimetry (TG/DTG) techniques were used for analyzing the Pd NPs@Fe3O4/CS-AG microcapsules. Characterization studies showed that Pd NPs@Fe3O4/CS-AG microcapsules were successfully synthesized and the size of the particles was in the range of 28–39 nm. Pd NPs@Fe3O4/CS-AG microcapsules displayed highly effective catalytic performance in the conversion of various aryl halides into the corresponding biaryl derivatives by Suzuki-Miyaura reaction under solvent-free conditions in 5 min. Pd NPs@Fe3O4/CS-AG microcapsules were also successfully employed in p-NP reduction to p-aminophenol (p-AP) in water at room temperature in 180 s. Moreover, reproducibility studies showed that Pd NPs@Fe3O4/CS-AG microcapsules were highly efficient and could be used many times in both catalytic reactions due to their magnetically separable nature. According to the results of this work, Pd NPs@Fe3O4/CS-AG microcapsules are highly efficient, economical, practical and environmentally superb catalysts for Suzuki-Miyaura reaction and p-NP reduction.

Characterization of Palladium Nanoparticles Produced by Healthy and Microwave-Injured Cells of Desulfovibrio desulfuricans and Escherichia coli.

Numerous studies have focused on the bacterial synthesis of palladium nanoparticles (bio-Pd NPs), via uptake of Pd (II) ions and their enzymatically-mediated reduction to Pd (0). Cells of Desulfovibrio desulfuricans (obligate anaerobe) and Escherichia coli (facultative anaerobe, grown anaerobically) were exposed to low-dose radiofrequency (RF) radiation(microwave (MW) energy) and the biosynthesized Pd NPs were compared. Resting cells were exposed to microwave energy before Pd (II)-challenge. MW-injured Pd (II)-treated cells (and non MW-treated controls) were contacted with H2 to promote Pd(II) reduction. By using scanning transmission electron microscopy (STEM) associated with a high-angle annular dark field (HAADF) detector and energy dispersive X-ray (EDX) spectrometry, the respective Pd NPs were compared with respect to their mean sizes, size distribution, location, composition, and structure. Differences were observed following MWinjury prior to Pd(II) exposure versus uninjured controls. With D. desulfuricans the bio-Pd NPs formed post-injury showed two NP populations with different sizes and morphologies. The first, mainly periplasmically-located, showed polycrystalline Pd nano-branches with different crystal orientations and sizes ranging between 20 and 30 nm. The second NPpopulation, mainly located intracellularly, comprised single crystals with sizes between 1 and 5 nm. Bio-Pd NPs were produced mainly intracellularly by injured cells of E. coli and comprised single crystals with a size distribution between 1 and 3 nm. The polydispersity index was reduced in the bio-Pd made by injured cells of E. coli and D. desulfuricans to 32% and 39%, respectively, of the values of uninjured controls, indicating an increase in NP homogeneity of 30–40% as a result of the prior MWinjury. The observations are discussed with respect to the different locations of Pd(II)-reducing hydrogenases in the two organisms and with respect to potential implications for the catalytic activity of the produced NPs following injury-associated altered NP patterning.

Microreactors for the continuous and green synthesis of palladium nanoparticles: Enhancement of the catalytic properties

Synthesis of palladium nanoparticles (PdNPs) employing green reagents like glucose and starch was performed in two different reaction configurations: (i) the conventional batch method and (ii) with continuous microreactor technology. The synthetized nanoparticles were characterized by XRD, UV–vis spectroscopy and TEM. The reaction conducted in the microreactor led onto smaller PdNPs with a monodispersed size distribution. The catalytic response of both obtained materials was tested on the reduction of 4-nitrophenol. As a result, the smaller PdNPs synthesized with the continuous flow presented higher catalytic activity due to the high catalytic surface area of the small nanoparticles.

PREPARATION AND STABILITY OF SILVER AND PALLADIUM NANOPARTICLES STABILIZED BY POLYETHER LAPROL 5003 IN N,N – DIMETHYLFORMAMIDE MEDIA

This paper is devoted to obtaining and investigating the stability of silver and palladium sols in N,N-dimethylformamide medium. Due to the unique properties exhibited by metals in the nanosized state, metallic nanoparticles are gaining increasing importance in various fields of application, science and technology. This makes the task of obtaining stable metal sols extremely urgent. The synthesis of aggregate-resistant organosols of metals is associated with a number of problems, since the metal sols obtained in organic media are much less stable than hydrosols. For this reason, there arises the challenge of choosing an appropriate stabilizer. In this study, the stabilizer was branched polyester Laprol 5003. A distinctive feature of the synthesis of silver sols was the absence of a special reducing agent, since N,N-dimethylformamide, used as a solvent, recovers silver cations itself. As a result, stable sols of silver and palladium have been obtained in N,N-dimethylformamide medium. Sodium borohydride was used as the reducing agent for the synthesis of palladium nanoparticles. Spectral studies of the resulting sols were carried out. The silver and palladium nanoparticles were sized up by scanning electron microscopy. The procedure has shown that the average size of the silver particles formed in the N,N-dimethylformamide medium is 4 ± 2 nm, which is substantially smaller than the particles obtained in isopropanol medium by the borohydride method. The silver sols aggregation in dimethylformamide under the action of potassium thiocyanate was studied via optical absorption spectroscopy. It has been found that the stability of the silver sol in dimethylformamide to the electrolyte is higher than that of the sol obtained in isopropanol. It has also been detected that several absorption bands are present in the optical spectrum of the palladium sol in dimethylformamide. The effect of the stabilizing polyester concentration on the stability of silver and palladium sols in N,N-dimethylformamide was studied. The result is that when the concentration of Laprol 5003 exceeds some quantity, a sharp increase in the aggregation time of sols is observed, which indicates a significant increase in their stability.

Recombinant peptide fusion proteins enable palladium nanoparticle growth

The soluble fraction of bacterial lysates containing repeat units of a metal binding domain (Pd4) fused to the carrier protein Green Fluorescent Protein (GFPuv) was used to direct palladium nanoparticle synthesis on the order of 2 nm. Characterization confirmed the synthesis of highly ordered materials, as evident by microscopy and elemental analysis, demonstrating the fact that crude bacterial lysates containing fusion peptides may be used in lieu of expensive, pure peptide.