Non-noble metals (Fe, Co or Cu) supported on N-doped carbons were investigated for the first time as electrocatalysts reduction of nitrobenzene to aniline in a half-cell setup. The prepared by pyrolysis composites activated carbon (AC) and polyaniline (PANI) with incorporated metal sites. electrocatalyst performance was strongly influenced nature synthesis method. For latter, different optimum identified each metal. Cu-based synthesised low amount PANI Cu relative AC, best based its onset...

Hydrocarbon oligomers, high-molecular-weight polymers, and polymer additives have been covered with 2−60 nmol of gold/cm2 in order to enhance the ionization efficiency for static secondary ion mass spectrometry (s-SIMS) measurements. Au-cationized molecules (up ∼3000 Da) fragments trimer) are observed positive spectra metallized polystyrene (PS) oligomer films. Beyond 3000 Da, entanglement chains prevents ejection intact from a "thick" organic film. This limit can be overcome by embedding...

Nanoparticles of undoped and copper-doped cobalt ferrite Co1-x Cu x Fe2O4 at very low dopant concentrations (x = 0; 0.02; 0.04; 0.06; 0.08) were successfully synthesized by pyrolysis the corresponding hetero metal octanoate precursors obtained via coprecipitation using ligand as precipitating agent. The then characterized FTIR, ICP-AES TG-DTA analyses results reveal formation a copper-cobalt-iron hydroxooctanoate represented formula [Co1-x Fe2(C8H15O2)6(OH)2·2H2O]. decomposition products...

The present theoretical study explores the interaction of various energetic molecular projectiles and clusters with a model polymeric surface, direct implications for surface analysis by mass spectrometry. projectile sizes (up to 23 kDa) are intermediate between polyatomic ions (SF(5), C(60)) used in secondary ion spectrometry large organic microdroplets generated, example, desorption electrospray ionization. target is amorphous polyethylene, already previous [Delcorte, A.; Garrison, B. J....

This work presents a simple, fast (20 min treatment), inexpensive, and highly efficient method for synthesizing nitrogen-doped titanium dioxide (N-TiO2) as an enhanced visible light photocatalyst. In this study, N-TiO2 coatings were fabricated by atmospheric pressure dielectric barrier discharge (DBD) at room temperature. The composition the chemical bonds of TiO2 characterized X-ray photoelectron spectroscopy (XPS) time-of-flight secondary ion mass (ToF-SIMS). results indicate that nitrogen...

The metallization procedure, proposed recently for signal improvement in organic secondary ion mass spectrometry (SIMS) (Delcorte, A.; Médard, N.; Bertrand, P. Anal. Chem. 2002, 74, 4955)., has been thoroughly tested a set of kilodalton molecules bearing various functional groups: Irganox 1010, polystyrene, polyalanine, and copper phthalocyanine. In addition to gold, we evaluate the effect silver evaporation as sample treatment prior static SIMS analysis. Ion yields, damage cross sections,...

Different from the conventional use of charged supports, assembly thin coatings by alternate adsorption oppositely polyelectrolytes was realized on a variety uncharged standard polymers, such as poly(propylene), poly(styrene), poly(methyl methacrylate), and poly(ethylene terephthalate). For multilayer buildup, polyelectrolyte pair poly(styrenesulfonate)/poly(choline methacrylate) used. The quality investigated UV/vis spectroscopy, time-of-flight secondary ion mass spectrometry (ToF-SIMS),...

Buckminsterfullerene projectiles have demonstrated their outstanding capabilities for the secondary ion mass spectrometric (SIMS) analysis of bulk organic films. In this contribution, we focus on modeling mechanisms energy transfer and sputtering induced by kiloelectronvolt C60 in molecular solids polymers, which are important from viewpoint applications not been theoretically studied yet. The chosen methodology relies dynamics (MD) simulations, with a coarse-grained representation samples...

Abstract A new type of polymer compound that allows the formation highly ordered microstructured films by casting from a volatile solvent in presence humidity, and its characterization ToF‐SIMS (time‐of‐flight secondary‐ion mass spectrometry) are presented. honeycomb structure is obtained activation 2,2,6,6‐tetramethyl‐1‐piperidinyloxyl (TEMPO)‐terminated polystyrene (PS) with p ‐toluenesulfonic acid (PTSA). The mechanism this reaction, leading to more polar PS termination, deduced simple...

With the recent developments in secondary ion mass spectrometry (SIMS), it is now possible to obtain molecular depth profiles and 3D images of organic thin films, i.e. SIMS where information spectrum retained through sputtering sample. Several approaches have been proposed for "damageless" profiling, including with SF5(+) C60(+) clusters, low energy Cs(+) ions and, more recently, large noble gas clusters (Ar500-5000(+)). In this article, we evaluate merits these different analysis...

Selective protein adsorption is a key challenge for the development of biosensors, separation technologies, and smart materials medicine biotechnologies. In this work, strategy was developed selective adsorption, based on use mixed polymer brushes composed poly(ethylene oxide) (PEO), protein-repellent polymer, poly(acrylic acid) (PAA), weak polyacid whose conformation changes according to pH ionic strength surrounding medium. A mixture lysozyme (Lyz), human serum albumin (HSA), fibrinogen...

In an effort to improve our understanding of large molecule emission in organic SIMS, the sub-kiloelectronvolt and kiloelectronvolt Ar atom-induced sputtering polystyrene tetramers adsorbed on Ag{111} is modeled using classical molecular dynamics. Above 1 keV, addition trajectories consisting successive collisions between individual atoms, we observe a significant number high action where several hundreds substrate atoms are moving simultaneously. These events can generate unusually yields...

The advantages and drawbacks of using either monatomic or buckminsterfullerene primary ions for metal-assisted secondary ion mass spectrometry (MetA-SIMS) are investigated a series organic samples including additive molecules, polyolefins, small peptides. Gold deposition is mostly performed by sputter-coating, in some cases, the results compared to those thermal evaporation (already used previous article: Delcorte, A.; Médard, N.; Bertrand, P. Anal. Chem. 2002, 74, 4955). microstructure...

In this study, a bio-derived precipitating agent/ligand, palm kernel oil, has been used as an alternative route for the green synthesis of nanoparticles Fe-doped Co3O4 via co-precipitation reaction. The oil was extracted from dried seeds by crushing, squeezing and filtration. reaction with potassium hydroxide, under reflux, yielded solution containing mixture carboxylate excess hydroxide ions, irrespective length saponification. as-obtained reacts aqueous iron cobalt ions to yield desired...

Polystyrene oligomers adsorbed on Ag{111} have been used as a model system for molecular dynamics study of polyatomic fragment ejection from large organic adsorbates metals. The simulation the interaction between incident 500 eV Ar atoms and sample predicts nature kinetic energy characteristic fragments observed in low-mass range experimental polystyrene secondary ion mass spectrum (SIMS). This agreement confirms that can be result collisional emission process. Moreover, results indicate...

Understanding the surface properties of microbial cells is a major challenge current microbiological research and key to efficiently exploit them in biotechnology. Here, we used three advanced analysis techniques with different sensitivity, probing depth, lateral resolution, that is, situ atomic force microscopy, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, gain insight into conidia human fungal pathogen Aspergillus fumigatus. We show native ultrastructure, protein...

The adsorption of a globular protein on chemically well controlled surfaces was investigated in order to correlate its orientation the surface properties. To this end, three different alkyl thiols, differing by their end group (−COOH, −CH3, and −NH2), were used build up self-assembled monolayers (SAMs) gold substrates. β-Lactoglobulin (βLG) then adsorbed these SAMs immersion phosphate buffer solution. modification with thiols subsequent proteins characterized ex situ polarization modulated...