Ultrafine Platinum Nanoparticles Uniformly Dispersed on Arrayed CN_x Nanotubes with High Electrochemical Activity

Abstract

The structure and electrochemical properties of arrayed nitrogen-containing carbon nanotube (CN x NT)−platinum nanoparticle (Pt NP) composites directly grown on Si substrates have been investigated. The CN x nanotube arrays were grown by microwave-plasma-enhanced chemical vapor deposition first and then acted as the template and support for Pt dispersion in the following sputtering process. Under the same sputtering conditions, it was found that well-separated Pt NPs would form with an average diameter of 2 nm on the arrayed NTs while a continuous Pt thin film was observed on the bare Si substrate. X-ray photoelectron spectroscopy (XPS), X-ray diffraction, and electron microscopy were employed to study bonding and structure changes with increasing deposition time. Implications of the C1s and N1s bonding changes in XPS and their possible relation to the NT−Pt composite structures with self-limited size distribution are discussed. Cyclic voltammograms show well-behaved curves in methanol oxidation, suggesting an efficient electronic conduction mechanism from the substrate via CN x NTs to reach individual Pt NPs is in operation. Such an integrated nanocomposite approach possesses a high potential for micro direct methanol fuel cell applications.

CNx-modified Fe3O4 as Pt nanoparticle support for the oxygen reduction reaction

“…After Pt is deposited on the surface of Fe 3 O 4 -CN x , the typical diffraction peaks of Fe 3 O 4 become relatively small, which may be explained by the relative intensity ration of the Pt, and the The peak at high-binding-energy, i.e., 401.2 eV, corresponds to nitrogen bonded in a threefold coordination (N-sp 2 ), which is a feature of N bonding with the graphite layer. The other peak present in the low-binding-energy side corresponds to the pyridine-type N bonding (N-sp 3 ), which results from the interlinked node morphology inside the CN x [31]. The area of the XPS peak could be qualitatively estimated the level of element content.…”

Synthesis and Site Structure of a Replica Platinum−Carbon Composite Formed Utilizing Ordered Mesopores of Aluminum-MCM-41 for Catalysis in Fuel Cells

“…1 The morphologic effects of Pt nanoparticles, films, and alloys on the oxygen reduction reaction were reported. 1,21 In contrast that the Pt nanoparticles have been formed on various types of controlled C materials, [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] the electric contact of Pt with C has never been controlled and monitored nanoscopically.…”

Carbon Nanotubes Supported Metal Nanoparticles for the Applications in Proton Exchange Membrane Fuel Cells (PEMFCs)

“…It can therefore avoid using functionalization processes that might be detrimental to the catalytic properties of the obtained metal/N-CNT composites (Maiyalagan et al, 2005; C.L. Sun et al, 2005; C.-H. Zamudio et al, 2006). For example, Maiyalagan et al (Maiyalagan et al, 2005) studied the electrocatalytic properties of Pt/N-CNTs synthesized by a reduction of Pt 2+ adsorbed on the surface of unfunctionalized N-CNTs.…”