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Synthesis and characterization of carbon nanotubes decorated with platinum nanoparticles

Dobrzański L. A., Pawlyta M., Krztoń A., Liszka B., Labisz K.

Journal of Achievements in Materials and Manufacturing Engineering

2010

Vol. 39, nr 2

184-189

Purpose: In presented work results of synthesis of carbon nanotubes decorated with platinum nanoparticles by organic colloidal process as an example of direct formation of nanoparticles onto CNTs are reported. Design/methodology/approach: CNT were grown by chemical vapour deposition (CVD) by the catalytic decomposition of CO. To improve metal deposition onto CNTs the purification procedure with a mixture of concentrated HNO3–H2SO4 and H2O2 reduction reagent was applied. CNT–nanocrystal composite was fabricated by direct deposition of nanoparticles onto the surface of CNTs. Chemical composition and crystallographic structure of the obtained Pt/CNT composites were confirmed by energy dispersive X-ray spectroscopy (EDS) and by X-ray diffraction (XRD) measurements, while transmission (TEM) and scanning electron microscopy (SEM) were used for characterization of the morphology of composite as well as the distribution of nanocrystals on the CNTs surfaces. Findings: High efficiency of proposed method was confirmed as well as possibility of the coating of Pt nanoparticles onto CNTs, without aggregation of these particles. Research limitations/implications: Many others noble metals such as palladium, platinum, gold and iridium can be used for deposition on the CNTs using described procedure. Originality/value: Obtained material can be employed in constructing various electrochemical sensors. As a result of increasing of the surface area of Pt caused by the reduction of the size of used particles, fabricated sensor may be characterized by higher sensitivity.

Voltammetric determination of caffeine at pt/carbon nanotubes composite modified glassy carbon electrode

Wei Y., Zhang L., Shao C., Li C.

Chemia Analityczna

2009

Vol. 54, No. 4

607-617

Platinum nanoparticles (Pt) supported on carbon nanotubes (CNTs) were used to modify glassy carbon electrode (GCE) in order to determine caffeine. In 0.01 mol L-1 H2SO4 solution, the modified electrode (Pt-CNTs-GCE) showed obvious electrocatalytic activitytowards oxidation of caffeine. The oxidation peak current increased significantly and the oxidation potential shifted negatively. All experimental parameters were optimised.The magnitude of the oxidation peak current of caffeine was proportional to its concentration over the range 1.0 x 10-6-1.0 x l0-4mol L-1 and detection limit was 2 * 10-7 mol L-1. Relative standard deviation (RSD) of seven replicate determinations of l x 10-5 mol L-1caffeine was 2.03%. The proposed method was applied to the determination of caffeine in real samples with the recovery in the range from 96.5% to 102%.

Nanocząsteczki platyny wsparte węglowymi nanorurkami użyto do modyfikacji elektrody z węgla szklistego w celu oznaczenia kofeiny. Zmodyfikowana elektroda wykazywała elektrokatalityczną aktywność w procesie utlenienia kofeiny. Prąd utleniania kofeiny wzrastał a potencjał piku woltamperometrycznego stawał się bardziej ujemny. Zoptymalizowano parametry eksperymentalne. Wysokość piku woltamperometrycznego rosła liniowo ze stężeniem kofeiny w zakresie 1.0x10-6-1.0x l O-4 mol L-1. Granica wykrywalności wyniosła 2 x 10-7mol L-1 a względne odchylenie standardowe dla stężenia l x 10-1mol L-1 wyniosło2.03%. Opracowaną metodę zastosowano do oznaczania kofeiny w rzeczywistych próbkach. Odzysk metody wyniósł od 96.5 do 102%.