PdCl2 Solution Research Articles

Synthesis and Characterization of New Palladium(II) Schiff Base Complexes Derived from β-Diketones and Diamines

A new series of heterocyclic Schiff bases were prepared from condensation of 1-phenyl-3-methyl-4-acetyl/benzoyl-pyrazolone with 4,4′-diaminodiphenylmethane and 4,4′-diaminodiphenyl ether, resulting in the formation of four novel Schiff base ligands. These ligands were then treated with ethanolic solution of PdCl2, to form corresponding palladium(II) complexes. These complexes were characterized by elemental analysis, IR, 1H NMR, TGA, magnetic susceptibility measurements and UV-visible absorption spectroscopy. All the Pd(II) complexes were found to have one coordinated water molecule. Schiff base ligands chelated with the metal atom through two donor sites N and O of azomethine (-C=N-) and phenolic (-OH) groups, respectively.

A comparative study of the physiological and biochemical properties of tomato (Lycopersicon esculentum M.) and maize (Zea mays L.) under palladium stress

There is great concern about the environmental impact and toxicity of palladium (Pd) because of its widespread use in automotive catalytic converters and other applications. Pd migrates and transforms in the environment and is absorbed by plant roots where it affects plant growth and eventually enters the food chain. Here we explored the effects of Pd on the physicochemical and biochemical characteristics of C3 (tomato) and C4 (maize) plants. We measured physicochemical and biochemical properties, including chlorophyll, protein, soluble sugar, antioxidant enzymes, malondialdehyde, proline, and root activity, in tomato and maize seedlings after cultivation in different concentrations of PdCl2 solution (0, 0.2, 0.5, and 1 mM) in order to observe how Pd stresses them. Results showed that, with increasing Pd concentration, chlorophyll a and chlorophyll b contents and root activity decreased. Meanwhile, malondialdehyde, proline, protein, and soluble sugar contents increased. After cultivation in 1 mM PdCl2, the Pd contents in the roots, stems, and leaves of tomato seedlings were 12.389, 1.132, and 0.206 mg/g, respectively. In general, Pd has significant effects on the physiological and biochemical properties of both tomato and maize. Additionally, tomato seedlings were more sensitive to Pd stress, photosynthesis in maize was less inhibited by Pd and the antioxidant capability of maize was stronger. These results indicated that maize (C4 plant) exhibited a higher tolerance to Pd than tomato (C3 plant). Pd migration in tomato was observed and the translocation factor (TF) was calculated. The values of TFstem/root, TFleaf/root, TFleaf/stem, and TFshoot/root were 0.09, 0.02, 0.18, and 0.11 in tomato seedlings, respectively. Pd accumulated most in the roots, followed in turn by stems, leaves, and only trace amount of Pd was transferred into shoots.

Localized surface plasmon resonance (LSPR) detection of hydrogen gas by Pd2+/Au core/shell like colloidal nanoparticles

A hydrogen detector colloidal solution based on the plasmonic properties of gold nanoparticles (GNPs) is presented. GNPs were prepared by pulsed laser ablation (PLA) of gold target in DI water. PdCl2 solution with different concentration was added to the obtained GNPs colloidal solutions. X-ray diffraction (XRD) confirmed the formation of metallic gold and presence of PdCl2 phases. Transmission electron microscope (TEM) images along with X-ray photoelectron spectroscopy (XPS) revealed formation of the core-shell-like structures of Pd2+/Au NPs. After hydrogenation, TEM revealed that the core-shell morphology changes into free NPs and XPS revealed formation of the metallic Pd phase. Voltammetry analysis showed a well absorption and desorption capability of hydrogen in this gold-PdCl2 plasmonic system. After adding PdCl2 aqueous solution, a red-shift from 522 to 526 nm was observed which was attributed to Pd2+ ion attraction by the negative surface charge of bare GNPs and formation a core-shell like morphology. The optical absorption peaks of PdCl2 (the range 207–236 nm) as well as the LSPR peak of GNPs were traced during diluted hydrogen (0.3–10%) injection in colloidal samples with different Au:Pd molar ratio. It was found that the PdCl2 peaks drop due to Pd2+→Pd0 conversion and more importantly, the gold peak undergoes blue shift due to change in chemical properties of GNPs surrounding. A good correlation between PdCl2 absorption intensity and gold LSPR peak position was found when hydrogen concentration was varied. In this correlation, a desirable detection capability for low concentrations of hydrogen (<4% range, the limit of hydrogen explosion) with a possible large number of points was observed. Finally, a model for the hydrogen sensing mechanism based on the LSPR effect was presented.

EFFECTS OF Pd2+ CONCENTRATION ON THE STRUCTURAL PROPERTY OF NICKEL-PLATED PLANT FIBER NON-WOVEN SHEET

In this work, a facile method combined with PdCl2 solution immersing and electroless deposition to fabricate nickel-plated plant fiber non-woven sheet is demonstrated. The effect of [Formula: see text] concentration on the structural property of plated sheet was investigated using X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. Results showed that increasing activated time and PdCl2 concentration would facilitate the enhancement of Pd-adsorbed amount on the substrate surface. It would facilitate the deposition of nickel atom, the reduction of the surface electrical resistivity and the crystallization of plated coating due to the high catalytic sites. In addition, the lowest PdCl2 effective concentration was reduced with the increased of activated time.

Fabrication of Pd/WO3 colloidal nanoparticles by laser ablation in liquid of tungsten for optical hydrogen detection

In this paper, tetragonal WO3 colloidal nanoparticles (NPs) were prepared by pulsed laser ablation in liquid of tungsten target in de-ionized water, followed by adding a PdCl2 solution immediately after the ablation process or hours after aging. X-ray photoelectron spectroscopy revealed that the surface chemical composition is a mixture of W5+, W6+, and O–H groups for which a defective WO2.8 surface composition was calculated. Transmission electron microscope images showed that only when PdCl2 is added immediately, Pd/WO3 core-shell NPs are formed spontaneously. UV-Vis spectrophotometry showed an increase in the optical bandgap due to NPs oxidation throughout the aging period. Thus, the spontaneous formation of the Pd/WO3 core-shell NPs was attributed to the presence of surface oxygen defects in newly formed NPs. With hydrogen exposure (&amp;lt;10%), Pd/WO3 solutions turned blue, indicating a gasochromic coloration ability which was used to detect different hydrogen concentrations below 10%. The dynamic response to different hydrogen concentrations was also studied at 630 nm constant wavelength. The results revealed that Pd/WO3 NPs obtained by the pristine WO3 colloidal solution show a better gasochromic performance, in both the coloration and response time.

Efficient detecting of TNT molecules using palladium nanoparticles/ cross shape pores like structure porous silicon

A set of porous silicon PSi samples with different cross-shaped pores like structures are successfully synthesized by using double successive wet anisotropic etching process: KOH wet chemical process and laser-assisted etching (LAE) process. Four different forms of palladium nanoparticles are deposited on PSi substrate to fabricate PdNPs/PSi heterostructures. Surface-enhanced Raman scattering (SERS)-active PdNPs/PSi heterostructures are fabricated and investigated for detecting Trinitrotoluene (TNT) molecules. Dipping plating process of PSi in 0.05 M concentration of PdCl2 solution at room temperature for 15 min is used to assemble spread of surface morphologies PdNPs layer over PSi. The results show that the SERS of heterostructures for TNT molecules expos strong reliance on the density of hot-spot junctions more than the local surface plasmonic of PdNPs. Analytical Enhancement factor (EF) of the Raman signal is varied according to the formed density of hot spots regions.

Localized surface plasmon resonance H2 detection by MoO3 colloidal nanoparticles fabricated by the flame synthesis method

Beside the noble metal nanoparticles (NPs), plasmonic semiconductors are being developed nowadays for a variety of applications such as catalyst, phototherapy and sensing technologies. In the present study, colloidal plasmonic MoO3 NPs with <20 nm mean size are prepared by flame synthesis as a rapid, cost effective, catalyst-free and atmospheric route. A Mo rod was converted to oxide nanopowder in an oxyhydrogen flame and collected on a water-cooled rotating substrate. Colloidal solutions of these particles were made by dispersing the MoO3 NPs into DI water. As a palladium precursor, solutions of aqueous PdCl2 were added to the colloidal NPs to make them sensitive to hydrogen. Formation of cubic Pd NPs in among the MoO3 NPs were recognized in TEM images for hydrogen-exposed samples. Upon hydrogen injection, a localized surface plasmon resonance (LSPR) absorption band was appeared in the UV–Vis absorption spectra at 700–800 nm region, which began to decline by further exposure time. Within few seconds of gas exposure, samples turned blue and longer exposure made them brownish. The LSPR peaks exhibited a spectral blue shift with a more hydrogenation, in agreement with the existing plasmonic model. In addition, a correlation between optical band gap and LSPR intensity was found. The colloidal Pd-MoO3 solutions then were employed for LSPR sensing of hydrogen at a concentration range of 0–5%. A pronounced LSPR linear sensitivity toward low concentration (<2.5%) of hydrogen was observed.

N-Hexane conversion on \u03b3-alumina supported palladium\u2013platinum catalysts

Two series of Pd–Pt/Al2O3 catalysts, characterized by high metal dispersions were prepared and investigated in the reaction of n-hexane conversion at the temperature < 300 °C. Incipient wetness co-impregnation of γ-alumina with the solutions of Pd(acac)2 and Pt(acac)2 led to relatively good Pd–Pt alloying. However, a similar catalyst preparation using solutions of PdCl2 and H2PtCl6 resulted in unsatisfactory homogenization; furthermore, significant amounts of chlorine were retained in the catalysts. The Pd–Pt alloy homogeneity has a significant effect on the relations of catalytic activities and product selectivities with Pd–Pt alloy composition. The relationship between the catalytic activity of chlorine-free Pd–Pt/Al2O3 catalysts and bulk Pd–Pt composition matches the accepted relation between the surface composition and bulk composition of Pd–Pt, reflecting a high surface enrichment in palladium. In contrast, for the chloride series of Pd–Pt/Al2O3, variations of the turnover frequency are directly correlated with the bulk composition, indicating that unalloyed, more active, Pt particles decide about the catalytic behavior. Pd/Al2O3 shows better than Pt/Al2O3 selectivity for isomerization, especially after reduction at higher temperatures, ≥ 500 °C. On alloying with Pt, for the Cl-free series the isomerization selectivity was very high for nearly all bimetallic catalysts and showed a synergistic effect for 20 at.% Pt. In contrast, for the Cl-containing series, the isomerization selectivity was proportional to the palladium content. The effect of reduction temperature on the isomerization propensity of Cl-containing Pd–Pt/Al2O3 catalysts was rather small, suggesting that possible variations in support acidity associated with chloride presence do not have large catalytic consequences, confirming the metal-only catalytic action in alkane isomerization carried out at the temperatures below 300 °C.

Bimetallic Au/Pd nanoparticles decorated ZnO nanowires for NO2 detection

Various mono-noble metal nanoparticles (NPs) have been used to improve the functionalities of semiconducting sensing materials for high-performance gas sensors. However, understanding the effect of bimetallic noble NPs on their gas sensing behaviors is limited. In this work, the bimetallic Au/Pd-NPs decorated ZnO nanowires (ZNWs) were fabricated to study their NO2 sensing performance through comparing with their counterparts of pristine ZNWs, and mono Au- or Pd-NPs decorated ZNWs. The bimetallic Au/Pd-NPs decorated ZNWs were prepared by dipping the pristine ZNWs in a mixed solution of HAuCl4, PdCl2, Na2CO3, and absolute ethanol with heating evaporation. The bimetallic Au/Pd-NPs decorated ZNWs exhibited higher response of 94.2, faster response/recovery time of 35 s / 30 s, and lower optimal operating temperature at 100 °C towards 1 ppm NO2 than the performance of pristine ZNWs and mono Au- or Pd-NPs decorated ZNWs. Meanwhile, good selectivity and reproducibility have been achieved by bimetallic Au/Pd-NPs decoration. The mechanism on the enhanced sensing performance of the bimetallic Au/Pd-NPs decorated ZNWs has also been investigated systematically.

Effect of Pretreatment on Magnetic Nanoparticle Growth on Graphene Surface and Magnetic Performance in Electroless Plating

Electroless plating involves sensitization, activation, and plating processes. Sensitization and activation are conducted by dipping the substrate in SnCl2 solution and PdCl2 solution, respectively. These pretreatment processes are required to plate the substrate with noncatalytic surfaces. We investigated the effect of sensitization on the magnetic properties of FeCoNi@graphene hybrids prepared via electroless plating. The solution concentrations during sensitization were varied to observe changes in the structural, morphological, and magnetic properties of FeCoNi@graphene using XRD, TEM, and VSM, respectively. Sensitization under high concentration produced a large amount of SnO2, resulting in low saturation magnetization. Further, the FeCoNi@graphene hybrid prepared via electroless plating without sensitization also exhibited low saturation magnetization owing to the formation of oxides and hydroxides. We prepared FeCoNi@graphene with a saturation magnetization of 40.8 emu/g under sensitization at low concentration; this is the highest saturation magnetization among the reported magnetic material@graphene hybrids prepared via electroless plating. This study provides guidelines for the pretreatment of graphene via electroless plating and should contribute to future studies on the synthesis of magnetic material@graphene hybrids.

Effect of preparation parameters on properties and performance of Pd/Al2O3 catalyst in saturation of olefins

The complete saturation of commercial olefin-containing (3.3 mol%) C4 stream over Pd/γ-Al2O3 catalysts was studied. The catalysts were prepared by wet impregnation of the support using acidified PdCl2 solutions. The effect of different preparation parameters such as HCl/PdCl2 ratio in impregnation solution, impregnation time and solution volume on palladium distribution and catalytic performance was investigated. The catalysts were characterized by N2 adsorption/desorption, ICP measurements, X-ray diffraction, temperature programmed desorption of ammonia (NH3-TPD) and scanning electron microscopy. Catalytic performance tests were carried out in a three-phase co-current trickle-bed reactor at 50 °C, 27 bar and high olefin conversions in accordance with industrial operating conditions. The catalysts showed different palladium distributions according to preparation procedure. The best performance was observed for egg-shell catalysts prepared by employing short impregnation times (5–10 min) and low competitor levels (HCl/PdCl2 = 2.2 mol mol−1) in impregnation solution. The catalyst lifetime was found to correlate with its activity which was explained by a parallel deactivation mechanism.

Silk fibroin fiber for selective palladium adsorption: Kinetic, isothermal and thermodynamic properties

The adsorption of metal ions to silk fibroin (SF) fiber from silkworm, Bombyx mori, was applied for recovering Pd2+ from aqueous solutions. In order to understand adsorption behavior, selectivity for Pd2+, kinetic, isothermal and thermodynamic analysis were carried out. The amount of Pd2+ adsorbed to SF was highest among the metals (Pt2+, Os4+ Ir4+, Rh3+ and Ru4+) used at both single and mixture solutions, which is suggesting high selectivity adsorbent for Pd2+. From dependence of contact time on amount of Pd2+ adsorbed in solutions of PdCl2 at 25 °C, the pseud-second order kinetic model was suitable to this system. From isothermal experiments the Langmuir parameters qm and KL were 46.3 mg g−1 and 3.85 L mg-1, respectively. The Freundlich parameters Kf and 1/n were 30.6 and 0.343, respectively. These imply large adsorption capacity for Pd2+ as nature on the SF adsorbent. According to the Klotz’s treatment, negative values ofΔＧ was obtained, which indicated that the adsorption process was thermodynamically feasible and spontaneous at 298–353 K. Positive value of enthalpy change means the adsorption of Pd2+ to the SF was endothermic. This implies that the change of entropy is dominant to adsorption of Pd2+ to SF.

EFFECTS OF ACTIVATED TIME ON STRUCTURAL PROPERTIES OF PLATED PLANT FIBER NONWOVEN SHEETS

In this work, the effects of activated time on the structural properties of plated plant fiber nonwoven sheet were investigated systematically using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Results showed that there existed a saturated adsorption state on the surface of sheet in the PdCl2 solution. The adsorbed rate and saturated adsorption capacity increased with the increase of PdCl2 concentration. As a result, the deposited quantity and crystallization characteristics of plated nonwoven sheets were firstly enhanced and then unchanged with increase of activated time. The Pd-adsorbed capacity reached saturation point when the activated time was 16[Formula: see text]min. The maximum plated quantity was 0.02 and 0.028[Formula: see text]g/cm2 when the concentration of activating solution was 0.015 and 0.15[Formula: see text]g/L on the surface of sheet.

The study of hydrogen sorption in palladium limited volume electrode from DEMA-TFO ionic liquid

Hydrogen sorption into palladium limited volume electrode (Pd-LVE) was studied in protic ionic liquid – diethylmethylammonium triflate (DEMA-TFO) using cyclic voltammetry (CV), chronopotentiometry (CP) and chronoamperometry (CA) at constant temperature (298 K). Pd-LVE was obtained potentiostatically from the aqueous solution of PdCl2. The results were compared with those obtained in aqueous 0.5 M H2SO4 solution. As the process of hydrogen sorption in ionic liquid medium is much less reversible than in acidic aqueous solution – the hydrogen pretreatment procedure (HPP) significantly increases the reversibility of this process at temperature of 298 K. The amount of absorbed hydrogen in DEMA-TFO is comparable with this in aqueous solution of acid and reaches the maximum value of H/Pd ca. 0.7. The hydrogen absorption isotherm was measured with the use of CV and CP techniques.

Surface Activation of Polymers Assisted By Picosecond Laser Pulses for Selective Metallization Via Electroless Deposition

The preparation of metallic tracks on non-conductive or semi-conductive substrates is attracting a strong scientific interest due to its useful applications in integrated circuit technology and its potential for miniaturization. The selective metallization on dielectric substrates can be carried out via laser-assisted direct writing techniques These involve processes such as thermally induced deposition, surface modification for subsequent electroless deposition as well as photocatalysis-mediated deposition among others [1]. Furthermore, a well-known methodology for producing metal tracks onto polymeric substrates is the so-called laser direct structuring (LDS) technology and is widely used for producing molded interconnect devices (MIDs). Conventional LDS uses polymeric materials loaded with a small amount of metallic compound (e.g. Pd particles) which after laser ablation can be released for catalyzing a further electroless plating process. Organometallic complexes based on palladium (Pd2+), copper (Cu2+) [2] as well as metal oxide composites of copper−chromium oxide (CuO·Cr2O3) or antimony-doped tin oxide (ATO) [3] have been used as catalyst sources for LDS technology in the last years. The active material is finely dispersed in the polymeric matrix and can be chemically modified by laser ablation in order to play a role as catalyst in a subsequent electroless deposition process. However, although the LDS method offers flexibility and freedom for 3D patterning design, the addition of those special additives (catalyst sources) is required in order to make the polymeric material suitable for LDS. This paper will discuss a simple methodology for patterning metal tracks onto the polymeric substrate polybutylene terephthalate (PBT). The selective metallization process consists of three main steps: (1) surface patterning and activation with picosecond-laser pulses in a dry processing environment; (2) treatment of the substrate in PdCl2 seeding solution, and (3) selective metallization of the substrate via electroless copper deposition. It was found that, besides a significant surface roughening, the use of ultra-short laser pulses promoted the chemical modification of the polymeric surface in a manner that the surface acquires the ability to reduce Pd-ions into metallic Pd clusters during a subsequent treatment in PdCl2 solution. The laser parameters as well as the concentration and the temperature of the PdCl2 solution were investigated and correlated with the surface morphology, the formation of Pd clusters as well as with the characteristics of the copper layers. The copper features were homogeneous and exhibited well defined geometries. Moreover, the adhesive properties of the copper structures were investigated. Tape tests showed that the copper structures exhibited good adhesion to the PBT substrate and this is ascribed to the high roughness obtained via laser patterning. The copper layers exhibit low electrical resistivity values and therefore show great potential for applications in electronic devices even with 3D complex geometries.

Deposition of Pd nanoparticles on the walls of cathodically hydrogenated TiO2 nanotube arrays via galvanic displacement: A novel route to produce exceptionally active and durable composite electrocatalysts for cost-effective hydrogen evolution

Noble metal-based materials are inevitable components of cathodes for the hydrogen evolution reaction (HER) in future water electrolysis systems for clean hydrogen fuel production. However, designing active and durable nanostructured catalysts with low amount of costly noble metals is still a great challenge. Herein, we show that Pd nanoparticles (NPs) can be synthesized on the highly developed surface of anodically grown TiO2 nanotube (TNT) arrays by applying a simple galvanic displacement strategy. In a two-step procedure, air-annealed TNT arrays are first cathodically protonated and then partially reoxidized by Pd(II) ions from a PdCl2 solution while providing a scaffold for the metallic Pd deposit. Structural and electrochemical characterizations reveal that the Pd content and the width of the Pd-populated zone of the tube walls are in correlation with the tube length. The Pd@TNT composites display remarkable HER activity in 1 M HClO4 delivering a current density of −10 mA cm−2 at an overpotential of −38 mV and a Tafel slope of only −13 mV/dec. More impressively, the mass and apparent activity of the Pd@TNTs is superior to even commercial Pt/C at higher current densities. The composites also show stable chronopotentiometric response over 25 h and a negligible HER overpotential increase after potential cycling tests. The exceptional performance of the Pd@TNT cathodes is assigned to the unique semiconducting properties of the three-dimensional, interactive TNT supporting structures that, on the one hand, provide abundance of Pd active sites with optimized atomic hydrogen binding energy for the cathodic HER, but on the other hand, prevent anodic degradation of the Pd catalyst.

Effects of surface coating with Cu-Pd on electrochemical properties of A2B7- type hydrogen storage alloy

La0.75Mg0.25Ni3.2Co0.2Al0.1 hydrogen storage alloy, the nickel-metal hydride (MH/Ni) secondary battery negative electrode, was modified by CuSO4 solution (3 wt% in Cu in contrast with alloy weight) and PdCl2 solution varied from 1 wt% to 4 wt% in Pd in contrast with alloy weight with a simplified pollution-free replacement plating method, aiming at improving its comprehensive electrochemical properties. The XRD analysis and SEM images combined with EDS results reveal that Cu and Pd nanoparticles are uniformly plated on the pristine alloy surface. The relative amount of Pd on the Cu-Pd coated alloy surface increases notably as the PdCl2 concentration increases in the plating solution. Electrochemical tests indicate that alloy electrodes modified by Cu-Pd composite coating show perfect activation performance, which achieve the maximum discharge capacity at the first charge-discharge cycle. Moreover, alloy electrodes coated with Cu-Pd perform dramatically enhanced high rate dischargeability (HRD). The enhancement increases firstly and then decreases as the content of Pd increases in the Cu-Pd coating. Meanwhile, the cycle life of modified alloys is also improved significantly. Among all the samples, the Cu-Pd coated alloy with 3 wt% Pd content in the PdCl2 solution reinforces the comprehensive electrochemical properties most sufficiently, with dischargeability of 86.4% under 1500 mA/g and remaining capacity of 82.7% after 100 cycles.

Green Synthesis of Palladium/Titanium Dioxide Nanoparticles and their Application for the Reduction of Methyl Orange, Congo Red and Rhodamine B in Aqueous Medium.

Palladium nanoparticles (Pd NPs) supported on the TiO2 NPs were prepared using Euphorbia thymifolia L. leaf extract. The Pd/TiO2 NPs were characterized by FESEM, EDS, TEM and XRD analysis and were used as nanocatalysts for the reduction of a variety of organic dyes. To the best of the author’s knowledge, this study explains the first report to the synthesis of Pd/TiO2 NPs using Euphorbia thymifolia L. leaf extract. 1.0 G of TiO2 was dispersed in 40 mL of 0.3 Mm PdCl2 solution and sonicated for 30 min. Then, 20 mL of the plant extract was mixed under continuous stirring at 60°C for 2 h. The prepared Pd/TiO2 NPs were centrifuged, washed and then dried. FESEM imaging showed the formation of NPs in the size range of 19-29 nm. The Pd/TiO2 NPs exhibited high activity towards the reduction of Methyl Orange, Congo red and Rhodamine B in the presence of NaBH4 in aqueous medium during 4, 1 and 54 s, respectively. The synthesis of the Pd/TiO2 NPs by this route is rapid, simple, less time consuming, environmentally safe and compatibility for medical and pharmaceutical applications because of minimizing the use of toxic or hazardous organic solvents and reagents. Furthermore, the biosyenthesized nanocatalyst can catalyze the reduction of organic dyes during short-time and can be recovered and recycled several times without significant loss of activity.

Antibacterial and cytotoxicity effects of biogenic palladium nanoparticles synthesized using fruit extract of Couroupita guianensis Aubl.

Herein, we report a facile route to synthesize palladium nanoparticles (CGPdNPs) using the aqueous fruit extract of C. guianensis Aubl. as a potent biological reducing agent. Reduction of PdCl2 solution into their nano scale was confirmed with the formation of a black precipitate which gives a reduced absorbance in UV–vis spectroscopy. Fourier transform infrared spectroscopy (FTIR) reveals the active role of phenolic constituents from C. guianensis in reduction and surface functionalization of nanoparticles (NPs). Dynamic light scattering (DLS) and zeta potential analysis confirms the generation of polydispersed highly stable NPs with large negative zeta value (−17.7mV). Interestingly, X-ray Diffraction (XRD) pattern shows that the synthesized CGPdNPs were face centered cubic crystalline in nature. The HRTEM micrographs of CGPdNPs displays well-dispersed, spherical NPs in the size ranges between 5 and 15nm with an average of 6nm. It was also noticed that the synthesized CGPdNPs possess an effective antimicrobial activity against different bacterial pathogens. On the other hand, in vitro cell viability (MTT) assays reveals that the synthesized CGPdNPs exhibited an extraordinary anticancer properties. Eventually, hemocompatibility assay depicts the safe nature of synthesized NPs for biomedical application.

Easily fabricated and recyclable Pd&Cu@Al catalyst for gram-scale phosphine-free Heck reactions with high TON

A unique Pd&Cu@Al catalyst was easily fabricated just by immersing commercial aluminum foil in a mixed xylene solution of PdCl2 and CuCl2. The catalyst fabrication process led to aluminum oxide coatings in situ, which supported the metal nanoparticles and enhanced their catalytic activities for the phosphine-free Heck reaction of aryl halides and styrenes with high turnover number (TON) up to 3.9×105. The reaction can be scaled up to at least 100mmol and has been applied in modification of drug Lapatinib’s intermediate with low metal residue. This novel catalyst is of good application potential in industrial production because it was extremely easy to be recycled, in regardless of the generation of the insoluble impurities or tars during the reaction processes.