Browse
Submit Data
Databases
API
Help

Dataset Information

22 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Noble-Metal Nanorod Cryoaerogels with Electrocatalytically Active Surface Sites.

ABSTRACT: Noble-metal-based electrocatalysts usually contain small nanoparticle building blocks to ensure a high specific surface area as the scene for the surface processes. Here, we show that relatively large noble-metal nanorods are also promising candidates to build up functional macrostructures with prominent electrocatalytic activity. After optimizing and upscaling the syntheses of gold nanorods and gold bipyramid-templated silver nanorods, cryoaerogels are fabricated on a conductive substrate via flash freezing and subsequent freeze drying. The versatile cryoaerogelation technique allows the formation of macrostructures with dendritic, open-pore structure facilitating the increase of the accessible nanorod surfaces. It is demonstrated via electrochemical oxidation and stripping test experiments that noble-metal surface sites are electrochemically active in redox reactions. Furthermore, gold nanorod cryoaerogels offer a platform for redox sensing, ethanol oxidation reaction, as well as glucose sensing. Compared to their simply drop-cast and dried counterparts, the noble-metal nanorod cryoaerogels offer enhanced activity due to the open porosity of the fabricated nanostructure while maintaining structural stability.

SUBMITTER: Zambo D

PROVIDER: S-EPMC8662650 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Customizable Ligand Exchange for Tailored Surface Property of Noble Metal Nanocrystals.

Project description:It is highly desirable, while still challenging, to obtain noble metal nanocrystals with custom capping ligands, because their colloidal synthesis relies on specific capping ligands for the shape control while conventional ligand exchange processes suffer from "the strong replaces the weak" limitation, which greatly hinders their applications. Herein, we report a general and effective ligand exchange approach that can replace the native capping ligands of noble metal nanocrystals with virtually any type of ligands, producing flexibly tailored surface properties. The key is to use diethylamine with conveniently switchable binding affinity to the metal surface as an intermediate ligand. As a strong ligand, it in its original form can effectively remove the native ligands; while protonated, it loses its binding affinity and facilitates the adsorption of new ligands, especially weak ones, onto the metal surface. By this means, the irreversible order in the conventional ligand exchange processes could be overcome. The efficacy of the strategy is demonstrated by mutual exchange of the capping ligands among cetyltrimethylammonium, citrate, polyvinylpyrrolidone, and oleylamine. This novel strategy significantly expands our ability to manipulate the surface property of noble metal nanocrystals and extends their applicability to a wide range of fields, particularly biomedical applications.

| S-EPMC6998038 | biostudies-literature

Critical role of intercalated water for electrocatalytically active nitrogen-doped graphitic systems.

Project description:Graphitic materials are essential in energy conversion and storage because of their excellent chemical and electrical properties. The strategy for obtaining functional graphitic materials involves graphite oxidation and subsequent dissolution in aqueous media, forming graphene-oxide nanosheets (GNs). Restacked GNs contain substantial intercalated water that can react with heteroatom dopants or the graphene lattice during reduction. We demonstrate that removal of intercalated water using simple solvent treatments causes significant structural reorganization, substantially affecting the oxygen reduction reaction (ORR) activity and stability of nitrogen-doped graphitic systems. Amid contrasting reports describing the ORR activity of GN-based catalysts in alkaline electrolytes, we demonstrate superior activity in an acidic electrolyte with an onset potential of ~0.9 V, a half-wave potential (E ½) of 0.71 V, and a selectivity for four-electron reduction of >95%. Further, durability testing showed E ½ retention >95% in N2- and O2-saturated solutions after 2000 cycles, demonstrating the highest ORR activity and stability reported to date for GN-based electrocatalysts in acidic media.

| S-EPMC4803488 | biostudies-literature

Noble metal nanoparticles for biosensing applications.

Project description:In the last decade the use of nanomaterials has been having a great impact in biosensing. In particular, the unique properties of noble metal nanoparticles have allowed for the development of new biosensing platforms with enhanced capabilities in the specific detection of bioanalytes. Noble metal nanoparticles show unique physicochemical properties (such as ease of functionalization via simple chemistry and high surface-to-volume ratios) that allied with their unique spectral and optical properties have prompted the development of a plethora of biosensing platforms. Additionally, they also provide an additional or enhanced layer of application for commonly used techniques, such as fluorescence, infrared and Raman spectroscopy. Herein we review the use of noble metal nanoparticles for biosensing strategies--from synthesis and functionalization to integration in molecular diagnostics platforms, with special focus on those that have made their way into the diagnostics laboratory.

| S-EPMC3304133 | biostudies-literature

On the role of surface diffusion in determining the shape or morphology of noble-metal nanocrystals.

Project description:Controlling the shape or morphology of metal nanocrystals is central to the realization of their many applications in catalysis, plasmonics, and electronics. In one of the approaches, the metal nanocrystals are grown from seeds of certain crystallinity through the addition of atomic species. In this case, manipulating the rates at which the atomic species are added onto different crystallographic planes of a seed has been actively explored to control the growth pattern of a seed and thereby the shape or morphology taken by the final product. Upon deposition, however, the adsorbed atoms (adatoms) may not stay at the same sites where the depositions occur. Instead, they can migrate to other sites on the seed owing to the involvement of surface diffusion, and this could lead to unexpected deviations from a desired growth pathway. Herein, we demonstrated that the growth pathway of a seed is indeed determined by the ratio between the rates for atom deposition and surface diffusion. Our result suggests that surface diffusion needs to be taken into account when controlling the shape or morphology of metal nanocrystals.

| S-EPMC3637688 | biostudies-literature

Surface Plasmon Resonance or Biocompatibility-Key Properties for Determining the Applicability of Noble Metal Nanoparticles.

Project description:Metal and in particular noble metal nanoparticles represent a very special class of materials which can be applied as prepared or as composite materials. In most of the cases, two main properties are exploited in a vast number of publications: biocompatibility and surface plasmon resonance (SPR). For instance, these two important properties are exploitable in plasmonic diagnostics, bioactive glasses/glass ceramics and catalysis. The most frequently applied noble metal nanoparticle that is universally applicable in all the previously mentioned research areas is gold, although in the case of bioactive glasses/glass ceramics, silver and copper nanoparticles are more frequently applied. The composite partners/supports/matrix/scaffolds for these nanoparticles can vary depending on the chosen application (biopolymers, semiconductor-based composites: TiO₂, WO₃, Bi₂WO₆, biomaterials: SiO₂ or P₂O₅-based glasses and glass ceramics, polymers: polyvinyl alcohol (PVA), Gelatin, polyethylene glycol (PEG), polylactic acid (PLA), etc.). The scientific works on these materials' applicability and the development of new approaches will be targeted in the present review, focusing in several cases on the functioning mechanism and on the role of the noble metal.

| S-EPMC5551879 | biostudies-other

Two-Dimensional Noble-Metal Chalcogenides and Phosphochalcogenides.

Project description:Noble-metal chalcogenides, dichalcogenides, and phosphochalcogenides are an emerging class of two-dimensional materials. Quantum confinement (number of layers) and defect engineering enables their properties to be tuned over a broad range, including metal-to-semiconductor transitions, magnetic ordering, and topological surface states. They possess various polytypes, often of similar formation energy, which can be accessed by selective synthesis approaches. They excel in mechanical, optical, and chemical sensing applications, and feature long-term air and moisture stability. In this Minireview, we summarize the recent progress in the field of noble-metal chalcogenides and phosphochalcogenides and highlight the structural complexity and its impact on applications.

| S-EPMC7463173 | biostudies-literature

Unusual 4H-phase twinned noble metal nanokites.

Project description:Twinning commonly exists in noble metals. In recent years, it has attracted increasing interest as it is powerful to tune the physicochemical properties of metallic nanomaterials. To the best of our knowledge, all the reported twinned noble metal structures exclusively possess the close-packed {111} twinning plane. Here, we report the discovery of non-close-packed twinning planes in our synthesized Au nanokites. By using the bent Au nanoribbons with unique 4H/face-centered cubic)/4H crystal-phase heterostructures as templates, Au nanokites with unusual twinned 4H-phase structures have been synthesized, which possess the non-close-packed {10[Formula: see text]2} or {10[Formula: see text]6} twinning plane. By using the Au nanokites as templates, twinned 4H-phase Au@Ag and Au@PdAg core-shell nanostructures have been synthesized. The discovery of 4H-phase twinned noble metal nanostructures may pave a way for the preparation of metal nanomaterials with unique twinned structures for various promising applications.

| S-EPMC6598997 | biostudies-literature

Elucidating Oxygen Reduction Active Sites in Pyrolyzed Metal-Nitrogen Coordinated Non-Precious-Metal Electrocatalyst Systems.

Project description:Detailed understanding of the nature of the active centers in non-precious-metal-based electrocatalyst, and their role in oxygen reduction reaction (ORR) mechanistic pathways will have a profound effect on successful commercialization of emission-free energy devices such as fuel cells. Recently, using pyrolyzed model structures of iron porphyrins, we have demonstrated that a covalent integration of the Fe-N x sites into ?-conjugated carbon basal plane modifies electron donating/withdrawing capability of the carbonaceous ligand, consequently improving ORR activity. Here, we employ a combination of in situ X-ray spectroscopy and electrochemical methods to identify the various structural and functional forms of the active centers in non-heme Fe/N/C catalysts. Both methods corroboratively confirm the single site 2e- × 2e- mechanism in alkaline media on the primary Fe2+-N4 centers and the dual-site 2e- × 2e- mechanism in acid media with the significant role of the surface bound coexisting Fe/Fe x O y nanoparticles (NPs) as the secondary active sites.

| S-EPMC4010287 | biostudies-literature

Metalloallostery and Transition Metal Signaling: Bioinorganic Copper Chemistry Beyond Active Sites.

Project description:Transition metal chemistry is essential to life, where metal binding to DNA, RNA, and proteins underpins all facets of the central dogma of biology. In this context, metals in proteins are typically studied as static active site cofactors. However, the emergence of transition metal signaling, where mobile metal pools can transiently bind to biological targets beyond active sites, is expanding this conventional view of bioinorganic chemistry. This Minireview focuses on the concept of metalloallostery, using copper as a canonical example of how metals can regulate protein function by binding to remote allosteric sites (e.g., exosites). We summarize advances in and prospects for the field, including imaging dynamic transition metal signaling pools, allosteric inhibition or activation of protein targets by metal binding, and metal-dependent signaling pathways that underlie nutrient vulnerabilities in diseases spanning obesity, fatty liver disease, cancer, and neurodegeneration.

| S-EPMC10754205 | biostudies-literature

Enhanced Charge Transport and Increased Active Sites on α-Fe<sub>2</sub>O<sub>3</sub> (110) Nanorod Surface Containing Oxygen Vacancies for Improved Solar Water Oxidation Performance.

Project description:The effect of oxygen vacancies (VO) on α-Fe2O3 (110) facet on the performance of photoelectrochemical (PEC) water splitting is researched by both experiments and density functional theory (DFT) calculations. The experimental results manifest that the enhancement in photocurrent density by the presence of VO is related with increased charge separation and charge-transfer efficiencies. The electrochemical analysis reveals that the sample with VO demonstrates an enhanced carrier density and reduced charge-transfer resistance. The results of DFT calculation indicate that the better charge separation is also contributed by the decrease of potential on the VO surface, which improves the hole transport from the bulk to the surface. The reduced charge-transfer resistance is owing to the greatly increased number of active sites. The current study provides important insight into the roles of VO on α-Fe2O3 photoanode, especially on its surface catalysis. The generated lesson is also helpful for the improvement of other PEC photoanode materials.

| S-EPMC6643919 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data