Platinum Nanomaterials Research Articles

Platinum Nanoparticles as Photoactive Substrates for Mass Spectrometry and Spectroscopy Sensors

Platinum nanomaterials are the focus of great expectations to expand the reach of modern sensor technology. In this work, we have evaluated the ability of different types of platinum nanoparticles to enhance the response of analytical techniques based on optical excitation methods, namely nanoparticle-assisted laser desorption/ionization (NALDI), Raman scattering (SERS), and infrared absorption (SEIRA). Physical (laser ablation) and chemical (redox) methods of synthesis have been employed to produce spherical particles with sizes ranging from a few to tens of nanometers, stabilized with different coating agents. The nanoparticles have then been tested as active substrate materials to enhance the sensitivity of NALDI of a model peptide (angiotensin I) and a synthetic polymer (PEG600) and those of SERS and SEIRA of a common chromophore (rhodamine 6G). A fairly similar overall performance is found for nanoparticles homogeneous in size synthesized by chemical reduction as for heterogeneous sets of particles p...

Controlled synthesis of porous platinum nanostructures for catalytic applications.

Porous platinum, that has outstanding catalytic and electrical properties and superior resistant characteristics to corrosion, has been widely applied in chemical, petrochemical, pharmaceutical, electronic, and automotive industries. As the catalytic activity and selectivity depend on the size, shape and structure of nanomaterials, the strategies for controlling these factors of platinum nanomaterials to get excellent catalytic properties are discussed. Here, recent advances in the design and preparation of various porous platinum nanostructures are reviewed, including wet-chemical synthesis, electro-deposition, galvanic replacement reaction and de-alloying technology. The applications of various platinum nanostructures are also discussed, especially in fuel cells.

Double-template electrosynthesis of platinum nanomaterials for sensing application

Platinum nanomaterials were synthesized through a double-template electrochemical deposition. Scanning electron microscope, energy dispersive X-ray spectroscopy and X-ray diffraction was used to investigate the morphology and ingredient changes during the fabrication process of platinum nanoparticles (PtNPs)/nanozinc oxide (nanoZnO) modified glassy carbon electrode (GCE). Electrochemical methods were adopted to characterize the sensing properties of the proposed modified electrode towards hydrogen peroxide (H2O2) and hydrazine hydrate (N2H4). The results indicated that the PtNPs/nanoZnO/GCE showed synergistic electrochemical effect for electrocatalytic reduction of H2O2 and electrocatalytic oxidation of N2H4. Take N2H4 sensing for example, the modified electrode displayed a fast response (<4s), high sensitivity (110μAmM−1cm−1) and broad linear in the range from 0.5 to 1300μM and 1300 to 6000μM with a relatively low detection limit of 0.2μM (S/N=3). Zero current potentiometry was used for in situ probing the changes of the interfacial potential during the electrocatalytic oxidation of N2H4 on the modified electrode.

Facile Synthesis of a Platinum Nanoflower Monolayer on a Single-Walled Carbon Nanotube Membrane and Its Application in Glucose Detection

Platinum nanomaterials have shown to be highly attractive due to their superior catalytic ability with high utilization efficiency. Electrodeposition is a flexible technique to produce nanostructures with controllable morphology and high purity. In this study, platinum nanoparticles with tunable structure were synthesized on a single-walled carbon nanotube membrane via cyclic voltammetry. Specifically, a Pt nanoflower monolayer consisting of numerous petal-like nanosheets with a high specific surface area was obtained under the optimized condition. The Pt nanosheet grew anisotropically along the ⟨111⟩ direction and showed a typical face-centered cubic crystal structure. Moreover, the as-prepared free-standing Pt nanoflower membrane exhibited excellent catalytic ability toward amperometric detection of glucose at neutral pH with a low detection limit and a wide linear range.

Double-template synthesis of platinum nanomaterials for oxygen reduction

Gas bubble dynamic template, a new green and promising template, can be used to prepare nanostructured materials with different shapes from electrochemical deposition processes. Different morphological platinum nanomaterials have been synthesized by the replacement reaction of the deposited copper nanomaterials which were obtained under negative potential along with H2 evolution (dynamic template) at a glassy carbon electrode. Scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and electrochemical methods were adopted to characterize their structures and properties. The nanomaterials platinum exhibited excellent catalytic activity toward oxygen reduction. The results demonstrated that the strategy is a simple, cost-effective, and potent method to prepare platinum nanomaterials.

Synthesis of Platinum Nanowire Networks Using a Soft Template

Platinum nanowire networks have been synthesized by chemical reduction of a platinum complex using sodium borohydride in the presence of a soft template formed by cetyltrimethylammonium bromide in a two-phase water-chloroform system. The interconnected polycrystalline nanowires possess the highest surface area (53 +/- 1 m2/g) and electroactive surface area (32.4 +/- 3.6 m2/g) reported for unsupported platinum nanomaterials; the high surface area results from the small average diameter of the nanowires (2.2 nm) and the 2-10 nm pores determined by nitrogen adsorption measurements. Synthetic control over the network was achieved simply by varying the stirring rate and reagent concentrations, in some cases leading to other types of nanostructures including wormlike platinum nanoparticles. Similarly, substitution of a palladium complex for platinum gives palladium nanowire networks. A mechanism of formation of the metal nanowire networks is proposed based on confined metal growth within a soft template consisting of a network of swollen inverse wormlike micelles.

Platinum Nanoflowers for Surface-Assisted Laser Desorption/Ionization Mass Spectrometry of Biomolecules

No-template synthesis of surface clean platinum nanomaterials with thin projections (petals) on the Pt nanoparticle surface, termed Pt nanoflowers, has been developed, and Pt nanoflowers have achieved superior performance on surface-assisted laser desorption/ionization mass spectrometry (SALDI−MS) of biomolecules. With this new material, one can obtain high-resolution mass spectra with lower laser energy and smaller sample amounts, and no organic matrix is needed for laser desorption/ionization. The mass spectra also have fewer obstacle peaks at the lower m/z region. Furthermore, this novel substrate is quite stable against aging and showed no sweet-spot problems, that is, equal sensitivity on the whole substrate surface. Various biomolecules, including peptides and phospholipids, were examined, and Pt nanoflowers showed good performance for matrix-free laser desorption/ionization MS of these materials.

Green and controlled synthesis of gold and platinum nanomaterials using vitamin B2: density-assisted self-assembly of nanospheres, wires and rods

For the first time, we report efficient density-assisted self-assembly synthesis of gold and platinum nanospheres, nanowires and nanorods using vitamin B2 (riboflavin) at room temperature without employing any special capping or dispersing agent; this environmentally benign and general approach affords a facile entry to production of shape-selective Au and Pt noble nanostructures, which can be extended to silver and palladium nanostructures.