Morphology Of Platinum Nanoparticles Research Articles

TEMPO-oxidized cellulose for in situ synthesis of Pt nanoparticles. Study of catalytic and antimicrobial properties

In this work, platinum nanoparticles (PtNPs) were synthesized by a modified polyol process using TEMPO-oxidized nanocellulose (TOCN) as a stabilizing and co-reducing agent. Different ratios of TOCN nanocellulose to Pt4+ ions were studied to establish the optimum stabilizing effect of PtNPs. The effect of different pH of aqueous TOCN suspensions on the morphology of PtNPs was also examined. It was proved that PtNPs can be obtained solely in the presence of TOCN without the use of an additional reducing agent or ethylene glycol. The morphology and structural properties of the nanocellulose‑platinum nanoparticles composites were assessed using spectroscopic, microscopic and diffraction techniques, The catalytic performance in 4-nitrophenol reduction was evaluated. Significant differences in reaction rate constants k were found depending on the pH of the TOCN suspension applied during Pt4+ reduction. The crucial effect of reaction conditions on PtNPs performance was confirmed in tests of antibacterial efficacy against E. coli.

Fabrication of platinum nanoparticle counter electrode for highly efficient dye-sensitized solar cells by controlled thermal reduction time

We report the effect of the thermal reduction time during sintering on the electrocatalytic activity and the morphology of platinum nanoparticles (Pt-NPs) fabricated using thermal decomposition method. A uniform and dense distribution of Pt-NPs on fluorine-doped tin oxide glass substrate was achieved by controlling the thermal reduction time higher than 15 min and this morphology of Pt-NPs was responded for high electrocatalytic performance of counter electrode (CE). As expected, the excellent electrocatalytic activity with low charge-transfer resistance of 1.04 Ω cm2 and highly conductivity of Pt-NPs CE prepared at the thermal reduction time of 15 min during sintering was obtained, which was desirable for dye-sensitized solar cells. The energy conversion efficiency of 9.43 % was obtained for the thermal reduction time of 15 min with fill factor of 63.05 %, Jsc of 18.82 mA cm−2 and Voc of 795 mV.

Evaluation of synthesized platinum nanoparticles on the MCF-7 and HepG-2 cancer cell lines

Platinum nanoparticles (PNPs) were synthesized by chemical reduction of potassium hexachloroplatinate (IV) with trisodium citrate under vigorous stirring and addition of sodium dodecyl sulfate as stabilizer reagent. Reducing agent was chosen depending on the oxidation reactions and potential values of the chemical materials used in the experiment. The aim of this study is to investigate the effects of PNPs on the different cancer cell lines and cytotoxicity study of this nanomaterial. The morphology of PNPs was investigated by scanning electron microscope (XL30, Philips Electronics, Amsterdam, The Netherlands) with the ability to perform elemental analysis by EDX. Malvern Zetasizer 3000 HSA (Malvern Instruments, Worcestershire, UK) was used to determine the distribution of particle size and zeta potential of PNPs. The cytotoxicity property of the nanoparticles was evaluated by MTT assay on MCF-7 and HepG-2 cell lines, and the cytotoxic concentration 50% values were determined for 24 h.

Pt nanoparticles/graphene paste electrode for sodium borohydride electrooxidation

The graphene paste electrode (GPE), modified with platinum nanoparticles (NPt), is fabricated and characterized by electrochemical impedance spectroscopy and cyclic voltammetry. Borohydride electrooxidation and hydrogen evolution reaction (HER) are investigated by cyclic voltammetry at surface of the fabricated electrode. Linear sweep voltammetry of NPt/GPE and NPt/carbon paste electrode in different concentrations of borohydride was studied. Results demonstrate good conductivity and electrocatalytic activity of NPt/GPE toward borohydride electrooxidation and HER. The morphology of platinum nanoparticles is studied by atomic force microscopy.

Structure and morphology of platinum nanoparticles with critical new issues of low- and high-index facets

In this paper, Pt nanoparticles were successfully prepared by modified polyol method using silver nitrate as an effective structure-modifying agent. The characterization of Pt nanoparticles was investigated by using UV-Vis-NIR spectroscopy, transmission electron microscopy (TEM) and high resolution (HR) TEM, and x-ray diffraction (XRD). The method of selected area electron diffraction (SEAD) was used to study the structure of Pt nanoparticles. The results showed that the as-prepared Pt nanoparticles exhibiting the complexity of surface structure and morphology could be used as efficient catalysts for polymer electrolyte membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs).