Mario Sergio Moreno

• Ph.D.
• Researcher at Bariloche Atomic Centre

Active packaging for reducing surrounding ethylene of climacteric produce is becoming more widespread in the global market. Their practical use requires shaping porous materials to confer mechanical strength, structural integrity, and improved handling properties. For this reason, powder materials and composites were studied to determine the evolut...

The presence of silver nanoparticles (AgNPs) in water bodies has emerged as a new environmental concern and the efficient separation of these nanoparticles remains a critical challenge. Here, we developed novel magnetic nanoflocculants for the recovery of AgNPs from water. Alternating layers of biopolymers, in particular, chitosan, alginate, and po...

Metal nanostructures have received significant attention in recent years owing to their peculiar physical and chemical properties, which span a wide range of practical applications in a variety of scientific and engineering fields. Herein, we report a study of the optical properties and application in the field enhancement of silver nanoplates (Ag-...

We explore the use of industrial sources of silicon and surfactant for obtaining low-cost MCM-41 materials and evaluate their performances as CO2 adsorbents. All of them presented a high specific surface area with different structural characteristics and textural properties. Interestingly, the MCM-41 manufactured with the most economical reagents p...

Different kinds of highly porous nanostructured carbon (xerogels) were obtained by a new synthetic strategy based on surface-driven polymerization of resorcinol–formaldehyde resin in the presence of zinc oxide (ZnO) nanostructures. The synthesis method involved spatially confined polycondensation of resorcinol with formaldehyde in the presence of Z...

We explore the use of industrial sources of silicon and surfactant for obtaining low-cost MCM-41 materials and evaluate their performance as CO2 adsorbents. All of them presented a high specific surface area with different structural characteristics and textural properties. The template was removed by using thermal treatments in an air atmosphere o...

The synergy of superparamagnetic iron oxide nanoparticles (SPIONs) and ionizing radiation (IR), attributed to reactive oxygen species (ROS) and DNA double-strand breaks (DSBs) increase, was widely investigated in different cancers, but scarcely in melanoma. Herein, SPIONs were evaluated as radiosensitizers in A-375 human melanoma cells. Moreover, t...

We propose here a novel green synthesis route of core-shell magnetic nanomaterials based on the polyol method, which uses bio-based substances (BBS) derived from biowaste, as stabilizer and directing agent. First, we studied the effect of BBS concentration on the size, morphology, and composition of magnetic iron oxides nanoparticles obtained in th...

Ni–Co catalysts supported on MgAl2O4–CeO2 were prepared by the sol–gel method. The solids were calcined under a reducing atmosphere to obtain Ni and/or Co active sites. The influence of the cobalt content (1, 3 and 5% w/w) was studied on bimetallic catalysts containing 8% w/w of Ni. The catalysts were characterized by TG, FTIR, SBET, AAS, XRD, TPR,...

Crystalline LiCoO2 nanoparticles were coated with NiO nanocrystals. The coating was made using a one-pot strategy by solution combustion synthesis with different weight percentages. The method used is simple, economical, and easily scalable. The resulting materials were characterized morphologically, structurally, and electrochemically by transmiss...

Lithium oxosilicate has the highest proportion of lithium among lithium silicates, which is desirable for applications. Although Li8SiO6 is a stable phase, its obtention as a polycrystalline pure phase is not reported yet, probably because of the high sensitivity of the system Li2O–SiO2 to the synthesis conditions. In this work, we adapted a citrat...

Two different synthesis approaches were used to prepare silver/iron oxides nanocomposites: the polyol synthesis and laser ablation. The nanocomposites consisted of 10–20 nm Ag nanoparticles immersed in 100––300 nm iron oxide structures, being the Ag:Fe greater for the nanomaterial prepared by the chemical procedure. Both nanomaterials were able to...

Composites resulting from the combination of magnetic nanoparticles (MNP) with an electric conductive matrix may produce a framework where the competition between different magnetic interactions, and the existence of free...

Controlling the accumulation of ethylene is important in fruit and vegetable packaging. In this work, the potential use of Ag-containing SBA-15 mesoporous silica adsorbent as ethylene scavenger is studied. The adsorption capacity and affinity toward this gas are probing as a function of Ag content and Ag nanospecies present in the materials that we...

Spinel LiMn2O4is a promising cathode material for lithium-ion batteries. However, bulk LiMn2O4commonly suffers from capacity fading due to the dissolution of Mn into the electrolyte during cycling. Moreover, bulk LiMn2O4exhibits a low Li+diffusion coefficient that limits the volume available to Li+storage. Herein, we report the synthesis of small h...

The thermal decomposition of organometallic precursors in the presence of surfactants and a long-chain alcohol is a valuable method to synthesize magnetic nanoparticles (MNPs) because it provides good control of the final morphology and crystallinity of the magnetic material. These parameters, and consequently the magnetic properties, depend on sev...

Co catalysts supported on La2O3-SiO2 binary systems were used in the steam ethanol reforming reaction for the production of hydrogen. Calcined and used catalysts were characterized by different techniques, in situ Raman spectroscopy, XPS and HRTEM to determine the Co species present in the solids before and after the reaction. The Co catalysts were...

Ag-Zeolite-based adsorbents were prepared in order to investigate the nature of the Ag species present in the structure and its correlation with their adsorption capacity and affinity towards ethylene. Na+ in NaA were partially replaced with Ag+ by varying the AgNO3 concentration used in the aqueous solutions, obtaining two dissimilar Ag+ exchange...

This paper addresses the development of new magnetic silica-based nanoadsorbents and evaluates their potential application in the removal of contaminants of emerging concern (CECs), polyaromatic hydrocarbons (PAHs) and aliphatic hydrocarbons. For this purpose, magnetic iron oxide nanoparticles were covered with a hybrid shell of silica and 3-(trime...

A one-pot strategy was developed to coat micro- and nanomaterials with crystalline nanoparticles. Three Li-based materials were coated by a solution combustion synthesis method. By this procedure, we obtained LiCoO2 nanoparticles covered with nanocrystals of NiO and Ag; LiMn2O4 nanoparticles covered with Ag, and LiNi0·5Mn1·5O4 microparticles covere...

A study to determine the optimal content of Nb(V) ethoxide required to efficiently catalyze the H2 sorption kinetics in the Mg/MgH2 system is reported. The materials were synthesized by hand mixing different amounts of additive (from 0.10 to 1 mol%) to pre-milled MgH2. Considering kinetics and capacity the best performance corresponds to a 0.25 mol...

Here, we propose the use of silver‐coated gold nanostars as the basis for a multiplex sensing system based on surface‐enhanced Raman scattering (SERS)/surface‐enhanced resonance Raman scattering (SERRS) ultrasensitive detection of porphyrins using a 532 nm laser excitation. By modifying the synthetic parameters, we were able to shift the plasmon pe...

It is now well-established that boundaries separating tetragonal-like (T) and rhombohedral-like (R) phases in BiFeO3 thin films can show enhanced electrical conductivity. However, the origin of this conductivity remains elusive. Here, we study mixed-phase BiFeO3 thin films, where local populations of T and R can be readily altered using stress and...

Thermal neutron attenuation capacity of Li4SiO4 was evaluated to assess its potential capabilities as a beam shaping material for boron neutron capture therapy (BNCT) facilities. Samples of Li4SiO4 were prepared by two different synthesis methods, using different raw materials and were characterized using x-ray, electron diffraction and transmissio...

In this work, we present the preparation of hybrid materials constituted by a Metal Organic Framework (type CPO-27-Mg) and a mesoporous silica (type KIT-6) which were successfully assembled through an in situ hydrothermal method. The composites were characterised by powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), th...

Fe/SBA-15 catalyst with different iron (Fe) loads (6% and 10% wt.) was synthesized via incipient wetness impregnation. The potential photocatalytic properties were tested using solar radiation, as a novel catalyst in heterogeneous Fenton approach to degrade Methyl Orange azo dye. A partial pore blocking of the substrate by Fe nanoparticles was dete...

Synthesis and characterization of hierarchical carbon materials, CMK-5 type, with high specific surface areas and large pore volumes is reported and tested in CO2 adsorption. These materials were successfully synthesized by the nanocasting process using a hard silica template SBA-15, furfuryl alcohol (FA) as carbon precursor, and 1,3,5-trimethylben...

Iron oxide particles were deposited in an ordered mesoporous material (SBA-15) with the aim of studying its behavior in the catalytic hydrogenation of CO (Fischer–Tropsch Synthesis). Bulk iron oxide, and iron supported on porous silica with different textural properties (Aerosil®-200) were used for comparison. The characterization of the materials...

CMK-3 carbons were synthesized varying the carbonization conditions and studying the effect of the templates calcined at different temperatures. The textural characterization of different SBA-15 templates calcined at 350, 450, and 550 °C shows a variation of the specific surface area below 10%. Based on the results, the SBA-15 obtained at 350 °C (t...

In the present work, an oil-in-water emulsion was developed for the encapsulation of xanthone, a potent anti-inflammatory and antitumor molecule of natural source. The xanthone is insoluble in water so it was encapsulated for oral administration purposes. Then, nonionic surfactants and bovine serum albumin protein for interface stabilization were u...

Zeolite/nanoparticle composites are synthesized and used as additive for waterborne formulations in replacement of traditional isothiazolinone-based biocides. Silver nanoparticles dispersed onto micrometer-sized crystals of A-type zeolite were prepared by thermal treatment or chemical reduction methods applied to the Ag-exchanged zeolite. The antif...

Fasciolosis is a zoonotic world widely distributed disease caused by the liver fluke Fasciola hepatica, which affects animals and occasionally humans. On the other hand, natural iron oxide particles like magnetite are commonly found in soils where they participate in a wide range of environmental processes like organic matter decomposition, the ads...

The Formic Acid Electro-oxidation (FAEO) on Pt/Au Nanoparticles (PtAu NP) supported on Hierarchical Porous Carbon (HPC), was studied by cyclic voltammetry and chronoamperometry. The supported HPC-Pt nanoparticles were surface modified by Au spontaneous deposits. The morphological and compositional characterization was performed by Scanning Electron...

Pt catalysts were prepared by encapsulating the active metal in the NaA zeolite structure. The catalysts were prepared by hydrothermal synthesis using two heating sources, conventional heating through a thermal bath and microwave radiation. The synthesis time was significantly reduced using microwave radiation without affecting the crystallinity or...

Gold nanoparticles with NIR absorption are promising for photothermal therapy applications. Different syntheses have been proposed and, among them, that based on the reduction of Au(III) with thiosulfate is important because it yields gold nanotriangles (AuNTs) with strong absorption in the near-infrared region. It has been previously reported by o...

Development of nanostructured electrodes for application in Li-ion batteries implies the control of particle morphology and size distribution. Using the high temperature thermal decomposition synthesis for different temperatures and changing the reactant concentration, we obtained highly crystalline LiFePO4 nanoparticles with different morphologies...

RESUMEN Se sintetizaron nanopartículas de óxido de litio cobalto (LiCoO2) utilizando el método de síntesis por combustión de soluciones. Se estudiaron cuatro relaciones combustible/oxidante (φe) en un rango de 0,5 a 1,25, utilizando almidón como combustible y nitrato de litio y de cobalto como oxidantes y fuente de metales. Uno de los procesos se l...

Ru catalysts on carbon fibers were prepared by electroless deposition, with 0.6 wt% Ru loading. The reduced and used catalysts were characterized by different techniques in order to analyze oxidation states and surface composition, the metallic content at volumetric level, and particle size. These solids were evaluated for the production of hydroge...

Embedding 2D layered materials into polymers and other materials as composites has resulted in the development of ultra-sensitive pressure sensors, tunable conductive stretchable polymers and thermoelectric coatings. As a wettable paint or ink, many 2D materials may be penciled, printed, or coated onto a range of surfaces for a variety of applicati...

The electronic structure of stoichiometric tin dioxide (SnO 2) is studied by probing its unoccupied states using the fine structure in the electron energy-loss spectra (EELS) at the oxygen-K (O-K) edge. The spectral measurements were performed both at room and at high temperatures (773 K) and compared to ab initio calculations carried out using the...

We have studied the products of the controversial synthesis of HAuCl4 with Na2S, which include gold nanostructures (Au NSs) that absorb in the near-infrared (NIR) and are highly promising for photothermal therapies and other nanomedical applications. From high resolution transmission electron microscopy, X-ray absorption spectroscopy and small angl...

The room temperature photoluminescence (PL) from ZnO/MgO core/shell nanowires (NWs) grown by a simple two-step vapour transport method was studied for various MgO shell widths (w). Two distinct effects induced by the MgO shell were clearly identified. The first one, related to the ZnO/MgO interface formation, is evidenced by strong enhancements of...

Embedding 2D layered materials into polymers can form a paint with many useful applications. In bulk form the thermoelectric material bismuth telluride (Bi 2 Te 3 ) has a high figure of merit (ZT) at room temperature. When bulk Bi 2 Te 3 is exfoliated to smaller dimensions, such as its 2D form (nanosheets), its thermoelectric effects are improved b...

Results of measurements of electronic energy loss for few keV protons and deuterons interacting with multi-walled carbon nanotubes are presented. Analyses of the energy loss distributions, for both type of ions, show a particular shape which is due to the cylindrical geometry of the nanotubes. These distributions can be explained in detail by a Mon...

The effects of catalyst matrix porosity composition on the catalytic performance have been studied using sulfonated mesoporous SBA-15 silica. The matrix was sulfonated with three different methods grafting, in situ oxidation, and carbon infiltration. Additionally, unordered sulfonated mesoporous carbon, and the commercial catalysts Amberlite IR-120...

In this work, we report the morphological and electrical characterization of highly crystalline LiCuXFe1-XPO4 nanoparticles synthesized via the high-temperature (380 °C) thermal decomposition of organometallic precursors. The mean diameter of the studied nanoparticles was 30-40 nm. The Cu/Fe relations of 0, 0.001 and 0.042 for the three studied sam...

Trimetallic PtMRu/C cathode catalysts with M = Co or Fe obtained by an impregnation procedure using ethylene glycol and NaBH4 as reducing agent, with suitable activity for the oxygen reduction reaction (ORR) and improved tolerance to methanol, have been physically characterized by HRTEM, EDS and XPS. The examined nanoparticles have a small particle...

Direct methanol fuel cells (DMFCs) generate electricity in a clean and efficient way, so they are a valuable alternative to traditional environmentally harmful technologies. Portable power sources are one of the applications of passive DMFCs. One of the requirements in these devices is the use of high alcohol concentration. Methanol permeation acro...

The characterization of the inclusion complex between 2-hydroxybenzophenone (2OHBP) and β-cyclodextrin (βCD) in the solid state was performed using Fourier-Transform infrared spectroscopy (FTIR), Powder X-ray diffractometry (PXRD), Differential scanning calorimetry (DSC), Thermogravimetric analysis (TGA) and Transmission electron microscopy (TEM)....

The aim of the present work was to investigate Rh nanoparticle catalysts supported on La2O3-SiO2, with different contents of La2O3, in the ethanol steam reforming reaction. The size of Rh particles was determined by both XPS, applying the Davis model, and CO chemisorption measurements. Particle sizes between 1.2 and 3 nm were estimated with these t...

We present an atomic resolution transmission electron microscopy (TEM) and scanning TEM (STEM) study of the local structure and composition of graphene oxide modified with Ba2+. In our experiments, which are carried out at 80 kV, the acquisition of contamination-free high-resolution STEM images is only possible while heating the sample above 400 °C...

In the design and engineering of functional core-shell nanostructures, materials characterization at small length scales remains one of the major challenges. Here we show how electron tomography in high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) mode can be applied successfully to perform nano-metrological chara...

Ni/MCM-41 samples have been successfully prepared by wet impregnation method with different degrees of metal loading. Various techniques including X-ray diffraction, N-2 adsorption-desorption, transmission electron microscopy, inductively coupled plasma atomic emission spectroscopy, electron microprobe analysis, UV-Vis diffuse reflectance spectra,...

An improvement in ethanol oxidation electrocatalysis is possible with multifunctional Pt-based combinations. Thus, the addition to Pt of Sn, Ir or Ni enhances the ethanol oxidation reaction (EO) and shifts the onset oxidation potential to lower values. It has been suggested that metallic oxides in the vicinity of Pt have the capacity of promoting t...

We have investigated experimentally and by computer simulations the energy-loss distributions of low-energy (E < 10 keV) protons and deuterons transmitted through polycrystalline palladium thin films. In contrast to previous experiments on various transition metals we find that the stopping power of Pd is proportional to the ion velocity. Data of p...

Nanometric inclusions filled with nitrogen, located adjacent to FenN (n¼3 or 4) nanocrystals within (Ga,Fe)N layers, are identified and characterized using scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS). High-resolution STEM images reveal a truncation of the Fe-N nanocrystals at their boundaries with t...

The particular properties of carbon nanoparticles (CNPs) have generated great interest in biomedicine, bioanalysis and optoelectronics. However, an association between the CNPs' physicochemical properties with their molecular and morphological characteristics is, even today, a topic of discussion. In this work, we use a simple method of synthesis w...

Supported PtSnIr/C, PtSn/C, and IrSn/C catalysts with potential application in a direct alcohol fuel cell were prepared by chemical reduction employing Pechini methodology. The catalyst particles were characterized by high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy (XPS)....

Electron energy-loss spectroscopy (EELS) is used to study p-doped layers in n-i-p amorphous thin film Si solar cells grown on steel foil substrates. For a solar cell in which an intrinsic amorphous hydrogenated Si (a-Si-H) layer is sandwiched between 10-nm-thick n-doped and p-doped a-Si:H layers, we assess whether core-loss EELS can be used to quan...

The fabrication and catalytic properties of hierarchical porous carbon loaded with PtRu particles was studied. A silica nanoparticles opal is filled with resorcinol/formaldehyde resin, which is then pyrolized to form a macroporous carbon. Depending on synthesis conditions the volume contraction induces mesopore formation in the macroporous carbon,...

Supported Pt–Sn–Ir/C (P), Pt–Sn/C (PO) and PtRu/C (BH) catalysts with potential application in a direct alcohol fuel cell (DAFC) were prepared by chemical reduction employing Pechini (P), Polyol (PO) and NaBH4 (BH) methodology. The catalyst particles were characterized by high resolution transmission electron microscopy (HRTEM), energy-dispersive X...

In this work we report the covalent functionalization of multiwalled carbon nanotubes (MWCNTs) with polyacrylonitrile (PAN) and polyvinylpyridine (PVP) by the graft from method. Differences in the electronic distribution of both polymers resulted in different interaction between polymers and the nanotubes. It was found that PVP chains wrapped the n...

High temperature solid state synthesis was used for preparation of LiFePO4/C composite material and cobalt doped LiFePO4/C composite material. Glycine assisted combustion method was involved as a carbon coating procedure. It uses glycine as a carbon precursor for conductive coating and connecting of active material nanoparticles. Two different samp...

The capability of silicon nanoparticles to increase the yield of reactive species upon 4 MeV X-ray irradiation of aqueous suspensions and C6 glioma cell cultures was investigated. ROS generation was detected and quantified using several specific probes. The particles were characterized by FTIR, XPS, TEM, DLS, luminescence, and adsorption spectrosco...

The goal of this study was to investigate how the binding of humic acids (HA) to magnetite nanoparticles affects the ability of the HA to generate reactive oxygen species (ROS) upon irradiation. To this end, magnetite nanoparticles coated with two different HA were prepared by the co-precipitation method. These particles were characterized by sever...

Electron energy-loss spectroscopy (EELS) is used to study the B distribution in a p-i-n layered solar cell structure. The boron concentration in the p-doped Si layer is expected to be ∼1021 cm−3 and should not exceed 1017 cm−3 in the neighbouring intrinsic layer. We show that B concentrations as low as 3×l020 cm−3 (0.6 at. %) can be measured using...

a b s t r a c t The goal of this study was to investigate how the binding of humic acids (HA) to magnetite nanoparticles affects the ability of the HA to generate reactive oxygen species (ROS) upon irradiation. To this end, mag-netite nanoparticles coated with two different HA were prepared by the co-precipitation method. These particles were chara...

Two types of samples of LiFePO4 cathode material for lithium ion batteries was synthesized by glycine assisted sintering in our laboratories. Different type of conductive carbon support was used during synthesis. Often used amorphous Super P carbon in the first sample was altered for multiwall carbon nanotubes in the second sample. Physical charact...

Direct mapping of the lithium spatial distribution and the chemical state provides critical information on structure-correlated lithium transport in electrode materials for lithium batteries. Nevertheless, probing lithium, the lightest solid element in the periodic table, poses an extreme challenge with traditional X-ray or electron scattering tech...

The effect of nitric/sulfuric acid oxidation treatment on commercial arc-discharge multiwall carbon nanotubes was studied. Purification and structure modifications were assessed via Transmission Electron Microscopy and Thermogravimetric Analysis; while changes in adsorption properties were monitored by nitrogen and methane adsorption isotherms. Aft...

Multiwalled carbon nanotubes were obtained by chemical vapor deposition of xylene–ferrocene and employed as supports for PtSn alloy nanoparticles synthesized by the polyol method. The same metal alloy catalyst was also supported on Vulcan XC-72R to compare the influence of the substrate on the catalyst behavior for ethanol oxidation.The physical ch...

Titanium is a corrosion-resistant and biocompatible material widely used in medical and dental implants. Titanium surfaces, however, are prone to bacterial colonization that could lead to infection, inflammation, and finally to implant failure. Silver nanoparticles (AgNPs) have demonstrated an excellent performance as biocides, and thus their integ...

This paper presents the synthesis and characterization of colloidal NaYF4 and NaYF4:20% Gd lanthanide nanocrystals. The nanoparticles were prepared by chemical route using co-thermolysis of Na(CF3COO), Y(CF3COO)3 and Gd(CF3COO)3 precursor in oleylamine surfactant/phenylether at Ts = 250 degrees C. By tuning the precursor/surfactant molar ratio duri...

Instrumentation and Techniques SymposiaFast mechanical shutter in Hitachi HF 3300, a 60 kV to 300 kV TEMArticle author querymalac m [PubMed] [Google Scholar]mcleod r [PubMed] [Google Scholar]li p [PubMed] [Google Scholar]bigelow w [PubMed] [Google Scholar]howe j [PubMed] [Google Scholar]allard l [PubMed] [Google Scholar]taniguchi y [PubMed]...

The preparation and characterisation of Pt nanoparticles electrodeposited on carbon substrates by pulsating electrolysis are presented. The characterisation studies of metal electrodeposits by using SEM, TEM, XRD and cyclic voltammetry revealed the presence of facetted Pt nanoparticles having a predominant (111) preferential crystal orientation. Th...

Pt-Sn-Ni/C and the Pt-Sn/C supported catalysts with potential application in a direct ethanol fuel cell (DEFC) were prepared by a chemical reduction method.The Vulcan XC-72R (Vu) used as carbon support was chemically treated with concentrated HNO3 (Vut) and then analyzed by thermal programmed desorption (TPD) and X-ray photoelectron spectroscopy (X...

The realization of materials at the nanometer scale creates new challenges for quantitative characterization and modeling as many physical and chemical properties at the nanoscale are highly size and shape-dependent. In particular, the accurate nanometrological characterization of noble metal nanoparticles (NPs) is crucial for understanding their o...

The structure of an intermediate form of tin oxide was investigated by precession electron diffraction. The results support a revised version of a layered, vacancy-ordered structure for Sn304 proposed in the preceding literature. The lattice parameters were found to be consistent with a monoclinic cell which is a distorted superlattice of the cassi...

of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

The effect of tungsten (W) on the growth of multi-walled carbon nanotubes (MWNTs) using the chemical vapour deposition (CVD) process over a metal Fe–W catalyst incorporated into a silica matrix is reported. A W molar content in Fe/SiO2 up to 10% was studied. The incorporation of only 2% of W substantially modifies the crystalline phases and the cry...

We have investigated the interaction between Pd and Ce in a (0.47 wt %) CeO _x– Pd (1 wt  %)/α -Al ₂ O ₃ catalyst that is used in the reforming reaction of CH ₄ with CO ₂ . The freshly reduced catalyst was characterized by various electron microscopy techniques, such as elemental mapping, Z -con...