A5061581191- Graphene research and applications
- Carbon Nanotubes in Composites
- Gold and Silver Nanoparticles Synthesis and Applications
- Molecular Junctions and Nanostructures
- Catalytic Processes in Materials Science
- Nanoparticles: synthesis and applications
- Electrocatalysts for Energy Conversion
- TiO2 Photocatalysis and Solar Cells
- ZnO doping and properties
- Semiconductor materials and devices
- Advanced Photocatalysis Techniques
- Multiferroics and related materials
- Electrochemical Analysis and Applications
- Nanocluster Synthesis and Applications
- Advancements in Battery Materials
- Fuel Cells and Related Materials
- Nanopore and Nanochannel Transport Studies
- Quantum Dots Synthesis And Properties
- Electrochemical sensors and biosensors
- Supercapacitor Materials and Fabrication
- Advanced battery technologies research
- Boron and Carbon Nanomaterials Research
- Plasmonic and Surface Plasmon Research
- Laser-Ablation Synthesis of Nanoparticles
- Nanoparticle-Based Drug Delivery
Universidad Nacional Autónoma de México
2015-2025
Center for Scientific Research and Higher Education at Ensenada
2023
Ensenada Institute of Technology
2019-2020
Institut Català de Nanociència i Nanotecnologia
2019-2020
Universidad Autónoma Monterrey
2020
Universidad Autónoma de Baja California
2015-2016
Universidade de Vigo
2009-2012
Institute for Scientific and Technological Research
2005-2009
Massachusetts Institute of Technology
2008-2009
Oak Ridge National Laboratory
2009
Graphene nanoribbons can exhibit either quasi-metallic or semiconducting behavior, depending on the atomic structure of their edges. Thus, it is important to control morphology and crystallinity these edges for practical purposes. We demonstrated an efficient edge-reconstruction process, at scale, graphitic by Joule heating. During heating electron beam irradiation, carbon atoms are vaporized, subsequently sharp step-edge arrays stabilized, mostly with zigzag- armchair-edge configurations....
We report the use of chemical vapor deposition (CVD) for bulk production (grams per day) long, thin, and highly crystalline graphene ribbons (<20-30 microm in length) exhibiting widths 20-300 nm small thicknesses (2-40 layers). These layers usually exhibit perfect ABAB... stacking as graphite crystals. The structure has been carefully characterized by several techniques electronic transport gas adsorption properties have measured. With this material available to researchers, it should be...
The establishment of covalent junctions between carbon nanotubes (CNTs) and the modification their straight tubular morphology are two strategies needed to successfully synthesize nanotube-based three-dimensional (3D) frameworks exhibiting superior material properties. Engineering such 3D structures in scalable synthetic processes still remains a challenge. This work pioneers bulk synthesis macroscale nanotube elastic solids directly via boron-doping strategy during chemical vapour...
More than ten years ago, it was suggested theoretically that boron nitride (BN) nanotubes could be produced. Soon after, various reports on their synthesis appeared and a new area of nanotube science born. This review aims to cover the latest advances related BN nanotubes. We show these tubes can now produced in larger amounts and, particular, chemistry appears very important production reinforced composites with insulating characteristics. From theoretical standpoint, we also (BN)-C...
We show extensive theoretical studies related to the generation and characterization of 2D 3D ordered networks using 1D units that are connected covalently. experimentally created multi-terminal junctions containing carbon blocks in order study most common morphologies branched structures could be used design network models. found mechanical electronic characteristics based on nanotubes (ON-CNTs) dominated by their specific super-architecture (hexagonal, cubic, square, diamond-type). charges...
Carbon nanotube growth in the presence of nitrogen has been subject much experimental scrutiny, sparking intense debate about role formation diverse structural features, including shortened length, reduced diameters, and bamboo-like multilayered nanotubules. In this paper, origin these features is elucidated using a combination theoretical techniques, showing that N acts as surfactant during growth. doping enhances smaller diameter tubes. It can also promote tube closure which includes...
Arrays of multiwalled carbon nanotubes doped with phosphorus (P) and nitrogen (N) are synthesized using a solution ferrocene, triphenyl-phosphine, benzylamine in conjunction spray pyrolysis. We demonstrate that iron phosphide (Fe3P) nanoparticles act as catalysts during nanotube growth, leading to the formation novel PN-doped nanotubes. The samples were examined by high resolution electron microscopy microanalysis techniques, their chemical stability was explored means thermogravimetric...
Highly symmetric gold nanoparticle clusters with coordination numbers up to seven were produced by using coating block copolymers. The resulting separated density gradient centrifugation and characterized SEM optical spectroscopy (see picture). Noble metal nanoparticles exhibit excitations known as surface plasmons that produce large enhancement of the local light intensity under external illumination, particularly when are arranged in closely spaced configurations.1 interparticle gap...
Gold nanostars can easily undergo reshaping into spherical particles by simply adding a small amount of CTAB. Such be understood in terms Ostwald ripening involving dissolution weakly bound surface atoms at areas with high convex curvature and re-deposition concave areas. This process stopped any time silver ions, which block bromide stabilize the surface. Because localized plasmon resonance (LSPR) band colloid gradually changes during etching, stabilization intermediate morphologies allows...
Buckypapers made with CNx nanotubes.
Going out on a limb: A combination of theoretical techniques, high-resolution microscopy, and energy-dispersive X-ray spectroscopy shows the role sulfur plays in branching phenomena during carbon nanotube (CNT) network growth. model is proposed which small amounts are enough to trigger growth bud CNT, leading kink formation subsequent branch (see SEM image).
Abstract We examine the possibility of controlling nanotube growth and simultaneously manipulating properties by adding elements in minute amounts (such as nitrogen, phosphorous, sulfur) that are different from carbon metal catalyst during process. This procedure is shown to be capable producing bamboo‐type morphologies, heterodoped nanotubes, Y‐junctions. also represents a critical step toward tailoring architectures, thus promoting development novel materials with unusual electronic...
The quantum transport properties of graphene nanoribbon networks are investigated using first-principles calculations based on density functional theory. Focusing systems that can be experimentally realized with existing techniques, both in-plane conductance in interconnected nanoribbons and tunneling out-of-plane intersections were studied. characteristics the ab initio electronic through cross-points is found to agreement results obtained semiempirical approaches. Both simulations confirm...
High and uniform near fields are localized at the eight similar sharp corners of cubic gold nanoparticles. Moreover, by introducing concavity in particle lateral planes, such field intensities can be further increased tuned infrared region without altering overall size Herein, we perform a thorough investigation morphological, crystallographic plasmonic properties concave nanocubes (GNCs) sub-70 nm range, for their potential application as highly efficient SERS substrates size-limiting...
Electrical current could be efficiently guided in 2D nanotube networks by introducing specific topological defects within the periodic framework. Using semiempirical transport calculations coupled with Landauer-Buttiker formalism of quantum multiterminal nanoscale systems, we provide a detailed analysis processes governing atomic-scale design circuits. We found that when are introduced as patches sites, they act bouncing centers reinject electrons along paths, via wave reflection process....
Water contamination is a worldwide concerning problem. Emerging contaminants have made conventional water treatment processes ineffective. This makes the search for new materials with improved physical-chemical properties an urgent necessity. Doping metal oxides nanostructures can improve photocatalytic degradation of and antimicrobial activity material. During this process, not only involves toxic pollutants, but also elimination virus bacteria. Then, it important to study effect dopant in...
Using density functional theory, we have studied a graphene structure with single C vacancy, doped three pyridinic N atoms and metallic adatom (Fe, Ni, Cu) as catalyst for the oxygen reduction reaction (ORR), one of most critical reactions in electrocatalysis. Nitrogen(N)-doped graphitic structures are promising candidates ORR, incorporation adatoms could improve their activity. Previous experimental theoretical reports indicate that Fe favors four-electron pathway, resulting formation water...
Abstract A detailed characterization, using high resolution electron microscopy/microanalysis (SEM, TEM, HRTEM, and EDX), reveals tubular carbon nanostructures exhibiting complex fascinating morphologies. The materials were obtained by sulfur‐assisted chemical vapor deposition. It is demonstrated that S not only acts on the catalyst, but also can be detected in lattice of nanostructures. experimental data presented here confirms critical role S, which responsible for inducing curvature...
N‐doped carbon nanostructures have gained attention as an alternative electrocatalyst for diverse reactions. They are making attractive the scalable methods to achieve enough material. However, optimizing appropriate nitrogen species in graphitic electrocatalysts is critical. Here, N‐doping process obtain graphene starting from oxide (GO) precursor contributing toward this goal explored. The role of doping temperatures and times on incorporation into sheets, subsequent desorption, influence...