Nanochemistry
Mir Reza Majidi; Seyran Ghaderi
Volume 6, Issue 3, pp. 218-324, Serial No. 20 , July 2018, , Pages 15-28
Abstract
In this work, the performance of graphene nanosheets (GNs) and graphene oxide (GO) nanosheets, as a support for palladium nanoparticles (PdNPs) toward oxygen reduction reaction (ORR), was studied. The graphene nanosheets were functionalized by a new and simple method. The PdNPs were synthesized on a ...
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In this work, the performance of graphene nanosheets (GNs) and graphene oxide (GO) nanosheets, as a support for palladium nanoparticles (PdNPs) toward oxygen reduction reaction (ORR), was studied. The graphene nanosheets were functionalized by a new and simple method. The PdNPs were synthesized on a glassy carbon electrode (GCE) modified with GNs or GO via a potentiostatic method; without using any templates, surfactants or stabilizers. The surface morphology of the modified electrodes was studied by scanning electron microscopy, energy dispersive X-ray and X-ray diffraction techniques. Cyclic voltammetry and rotating disk electrode (RDE) voltammetry methods were used for calculation of electrochemical parameters of the ORR. The GCE modified with PdNPs-GO exhibited a higher catalytic activity in comparison with PdNPs-GNs toward ORR. The high electrocatalytic activity of PdNPs-GO/GCE was attributed to oxygen-containing groups that were formed on the GO during functionalization of graphene nanosheets. These groups act as anchoring sites for metal nanoparticles and improve their dispersion on GO nanosheets. Also, mechanism of ORR was intensively investigated and transferred electron numbers in reaction was calculated using RDE data analysis. Finally, stability of the modified electrodes was studied and the results confirmed that the GCE modified with PdNPs-GO has a long-term stability.
Nanochemistry
Hassan Karami; Mohammad Ali karimi; Ehsan Atin
Volume 4, Issue 4, pp. 359-490, Serial No. 13 , October 2016, , Pages 449-465
Abstract
This paper presents a new gel combustion method to synthesize palladium nanoparticles, palladium oxide (PdO) nanoparticles and palladium-palladium oxide nanocomposites. In the proposed method, there are some effective parameters including palladium chloride concentration, polyvinyl alcohol (PVA) concentration, ...
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This paper presents a new gel combustion method to synthesize palladium nanoparticles, palladium oxide (PdO) nanoparticles and palladium-palladium oxide nanocomposites. In the proposed method, there are some effective parameters including palladium chloride concentration, polyvinyl alcohol (PVA) concentration, acid concentration, solvent composition and combustion temperature that their values are investigated and optimized by the "one at a time" method. The experimental data shows that the combustion temperature is the main factor that controls the sample composition to obtain palladium, palladium oxide or palladium-palladium nanocomposites. Characterization of the synthesized samples is performed by SEM, TEM, XRD and BET specific surface area measurements. The optimized sample consisted of clusters; each cluster is composed of smaller nanoparticles with an average diameter of 25 mm and 10 m2. g-1 specific surface areas. The optimized Pd-PdO nanocomposite is successfully used as nanocatalyst for the hydrogen revolution.
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