Palladium nanoparticles of average size around 8 nm have been synthesized rapidly by UV irradiation of mixture of palladium chloride and potassium oxalate solutions. A rod-shaped palladium oxalate complex has been observed as an intermediate. In the absence of potassium oxalate, no Pd nanoparticles have been observed. The synthesized Pd nanoparticles have been characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selective area electron diffraction and energy dispersive analysis by X-rays (EDAX) analyses. XRD analysis indicates the preferential orientation of catalytically activeticles. A plausible mechanism has been proposed for the formation of anisotropic Pd nanoparticles.

S. Navaladian

Balasubramanian Viswanathan

Thirukkallam Kanthadai Varadarajan

Ram Prasad Viswanath

PD NANOPARTICLES

POTASSIUM OXALATE

Preferential orientation

Texture coefficient

UV irradiation

Chlorine compounds

Diffraction

irradiation

Nanoparticles

Palladium

potassium

Synthesis (chemical)

Textures

Transmission electron microscopy

X ray analysis

X ray diffraction analysis

Palladium compounds

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IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Nanoscale Research Letters

The product distribution of electrochemical reduction of CO2 can be altered by modifying the surface of pure copper by deposition. In this study, chronoamperometric deposition of Cu on Cu (Cu/Cu) was carried out at two different CuSO4 bath concentrations, 0.25 M (high) and 0.025 M (low), termed as Cu/Cu-H and Cu/Cu-L respectively. These deposits were characterized by X-ray diffraction and they vary in their crystal orientation. Pure Cu and Cu/Cu were aligned towards (1 1 1) and (2 2 0) plane with a texture coefficient of 1.2 and 1.7, respectively. Electrodeposited electrodes were tested for the electrochemical reduction of CO2 in KCl electrolyte and the results were compared with that of pure Cu electrode. Electrochemical reduction of CO2 showed methane and ethane, with hydrogen as the byproduct. The product distribution varied with the crystal orientation of Cu electrodes. The maximum Faradaic efficiency of methane was 26% obtained on pure Cu electrode with (1 1 1) and (2 0 0) orientation, whereas Cu/Cu-L with dominating (2 2 0) orientation showed a maximum formation of ethane with Faradaic efficiency of 43%. A possible mechanism of product formation on Cu towards C1 and Cu/Cu towards C2 is also discussed. © 2014 Elsevier B.V.

Catalysis Today

Electrochemical reduction of CO2 on electrodeposited Cu electrodes crystalline phase sensitivity on selectivity

Palladium nanoparticles (PdNPs) of uniform size in the range of 3-5 nm are prepared in MeOH and MeCN:MeOH by solvent-assisted reduction of palladium acetate in the presence of a hexaazamacrocyclic ligand, L1. For the mixed solvent system different ratio of the solvents was tried i.e., 1:1, 1:3 and 3:1. In all cases the concentration and ratio of Pd(II) to L1 was maintained at 2mM:1mM. In another experiment NPs were prepared in MeOH by lowering the concentration of L1 to 0.5mM, where chain-like assemblies of PdNPs was observed. Importantly, the solutions are found to be stable at RT for months. © Indian Academy of Sciences.

Journal of Chemical Sciences

Synthesis of azamacrocycle stabilized palladium nanoparticles: Controlled size and one-dimensional growth

Worm-like nanorods and nanospheres of silver have been synthesized by photochemical decomposition of silver oxalate in water by UV irradiation in the presence of CTAB and PVP, respectively. No external seeds have been employed for the synthesis of Ag nanorods. The synthesized Ag colloids have been characterized by UV-visible spectra, powder XRD, HRTEM, and selected area electron diffraction (SAED). Ag nanospheres of average size around 2 nm have been obtained in the presence of PVP. XRD and TEM analyses revealed that top and basal planes of nanorods are bound with {111} facets. Williamson-Hall plot has revealed the presence of defects in the Ag nanospheres and nanorods. Formation of defective Ag nanocrystals is attributed to the heating effect of UV-visible irradiation.

Fabrication of worm-like nanorods and ultrafine nanospheres of silver via solid-state photochemical decomposition

Single crystalline silver nanoparticles have been synthesized by thermal decomposition of silver oxalate in water and in ethylene glycol. Polyvinyl alcohol (PVA) was employed as a capping agent. The particles were spherical in shape with size below 10 nm. The chemical reduction of silver oxalate by PVA was also observed. Increase of the polymer concentration led to a decrease in the size of Ag particles. Ag nanoparticle was not formed in the absence of PVA. Antibacterial activity of the Ag colloid was studied by disc diffusion method.

Thermal decomposition as route for silver nanoparticles

Polycrystalline gold nanowires were synthesized by a simple chemical reduction method using potassium oxalate as the reducing and capping agent along with polyvinylpyrrolidone (PVP) as the co-capping agent at room temperature. Different molar concentration ratios of HAuCl4 and potassium oxalate were studied for the synthesis of Au nanowires. Kinetics studies for Au colloid formation were carried out using UV-vis spectroscopic technique for the various concentration ratios of the reactants. As the concentration of oxalate was increased, the rate of reduction as well as particle growth was found to increase. XRD and TEM analyses revealed the formation of polycrystalline Au nanowires with a preferential growth of the {111} facet. In the absence of PVP, no Au colloid was formed. Studies revealed that the formation of the Au nanowire was due to the bridging nature of the oxalate dianion. The formation of Pt nanowires further supported the role of oxalate when the same method was adopted for the synthesis of Pt nanowires without using PVP. A plausible mechanism was proposed for the formation of Au nanowires explaining the role of oxalate. © 2007 American Chemical Society.

Journal of Physical Chemistry C

A facile room-temperature synthesis of gold nanowires by oxalate reduction method

Journal	Nanoscale Research Letters
ISSN	19317573
Open Access	Yes