Pt Nanoparticle Binding on Functionalized Multiwalled Carbon Nanotubes

Abstract

To create new catalyst materials for fuel cell applications, multiwalled carbon nanotubes (CNTs) were functionalized with sCdO, sCsOsCs, sCOOs, and sCsOH groups using a sonochemical treatment method under acidic aqueous solution (HNO 3 /H 2 SO 4 ) conditions to make them amenable to deposition of highly dispersed, ∼4 nm diameter Pt nanoparticles. The Pt-CNT interface was probed with X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure spectroscopy (EXAFS), and Raman and attenuated total reflection infrared (ATR-IR) spectroscopies to elucidate the nature of the Pt cluster-CNT surface binding. The degree of disorder of the sp 3 -hybridized C from the CNTs, as measured by the Raman D-to-G integrated peak area ratios, increased with the degree of surface oxidation of the CNTs. EXAFS of the Pt L III edge showed Pt coordination with oxygen (in the form of PtO x ) at the outermost perimeter of the Pt clusters while the majority of the bulk, as shown by the XPS Pt 4f core level, was in the metallic form. Infrared measurements showed that the carbonyl CdO stretching at 1700 cm -1 red shifted to ∼1550 cm -1 following Pt cluster deposition. In addition, changes in the CsO structural features at ∼1030 and 1150 cm -1 were observed, indicative of Pt cluster binding with the ionic form of carboxylate, COO(Pt), or ester-like, C(dO)CO(Pt), O atoms.

Platinum and palladium on carbon nanotubes: Experimental and theoretical studies

“…We note that the interaction we observe differs from that of Hull et al who deposited pre-prepared Pt nanoclusters onto functionalised carbon nanotubes [31]. In this case, while the majority of the Pt was present in metallic form, they observed a weak XPS signal indicating PtO x formation on the nanocluster surfaces.…”

Cu2ZnSnS4–PtM (M = Co, Ni) Nanoheterostructures for Photocatalytic Hydrogen Evolution

“…Figure 3 shows the Pt 4f and Co 2p XPS spectra obtained from CZTS−Pt and CZTS−PtCo nanoheterostructures. As for monometallic CZTS−Pt (Figure 3a), 19 the Pt 4f spectrum of CZTS−PtCo (Figure 3b) presented relatively broad bands, which pointed to the presence of at least two pairs of doublets and thus two Pt chemical states, Pt 0 and Pt 2+ . From the fitting of the spectra it became clear that in both samples the metallic Pt 0 state is the main component.…”

Facile synthesis and application of Ag-chemically converted graphene nanocomposite

“…The loss of intensity of the peak at 3450 cm -1 confirms the involvement and reduction of oxygen-containing groups in the formation of the Ag nanoparticles. Besides, it also suggests that strong interactions may exist between the Ag nanoparticles and the remaining surface hydroxyl O atoms [67]. Interestingly, the interactions between the nanoparticles and CCG were strong enough to ensure the nanoparticles remained attached even after chemical cleaning and ultrasonication.…”