Browse
Submit Data
Databases
API
Help

Dataset Information

27 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Nano conductive ceramic wedged graphene composites as highly efficient metal supports for oxygen reduction.

ABSTRACT: A novel conductive ceramic/graphene nanocomposite is prepared to prohibit the re-stacking of reduced graphene oxide (RGO) by wedging zirconium diboride (ZrB2) nanoparticles (NPs) into multiple layer nanosheets using a simple solvothermal method. Surprisingly, the RGO/ZrB2 nanocomposite supported Pt NPs shows very excellent catalytic activity. Its electrochemical surface area (ECSA) is up to 148 m(2)g(-1) (very approaches the geometry surface area of 155 m(2)g(-1)), much greater than that of the previous report (usually less than 100 m(2)g(-1)). The mass activity is as high as 16.8 A/g(-1), which is almost 2 times and 5 times that of Pt/RGO (8.6 A/g(-1)) and Pt/C (3.2 A/g(-1)), respectively, as benchmarks. Moreover, after 4000 cycles the catalyst shows only 61% of ECSA loss, meaning a predominantly electrochemical stability. The remarkably improved electrochemical properties with much high Pt utilization of the new catalyst show a promising application in low temperature fuel cells and broader fields.

SUBMITTER: Wu P

PROVIDER: S-EPMC3913918 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Bulk Polymer-Derived Ceramic Composites of Graphene Oxide.

Project description:Bulk polymer-derived ceramic (PDC) composites of SiCO with an embedded graphene network were produced using graphene-coated poly(vinyl alcohol) (PVA) foams as templates. The pyrolysis of green bodies containing cross-linked polysiloxane, PVA foams, and graphene oxide (GO) resulted in the decomposition of PVA foams, compression of GO layers, and formation of graphitic domains adjacent to GO within the SiCO composite, leading to SiCO composites with an embedded graphene network. The SiCO/GO composite, with about 1.5% GO in the ceramic matrix, offered an increase in the electrical conductivity by more than 4 orders of magnitude compared to that of pure SiCO ceramics. Additionally, the unique graphene network in the SiCO demonstrated a drop in the observed thermal conductivity of the composite (∼0.8 W m-1 K-1). Young's modulus of the as-fabricated SiCO/GO composites was found to be around 210 MPa, which is notably higher than the reported values for similar composites fabricated from only ceramic precursors and PVA foams. The present approach demonstrates a facile and cost-effective method of producing bulk PDC composites with high electrical conductivity, good thermal stability, and low thermal conductivity.

| S-EPMC6641334 | biostudies-literature

Tough metal-ceramic composites with multifunctional nacre-like architecture.

Project description:The brick-and-mortar architecture of biological nacre has inspired the development of synthetic composites with enhanced fracture toughness and multiple functionalities. While the use of metals as the "mortar" phase is an attractive option to maximize fracture toughness of bulk composites, non-mechanical functionalities potentially enabled by the presence of a metal in the structure remain relatively limited and unexplored. Using iron as the mortar phase, we develop and investigate nacre-like composites with high fracture toughness and stiffness combined with unique magnetic, electrical and thermal functionalities. Such metal-ceramic composites are prepared through the sol-gel deposition of iron-based coatings on alumina platelets and the magnetically-driven assembly of the pre-coated platelets into nacre-like architectures, followed by pressure-assisted densification at 1450 °C. With the help of state-of-the-art characterization techniques, we show that this processing route leads to lightweight inorganic structures that display outstanding fracture resistance, show noticeable magnetization and are amenable to fast induction heating. Materials with this set of properties might find use in transport, aerospace and robotic applications that require weight minimization combined with magnetic, electrical or thermal functionalities.

| S-EPMC7810751 | biostudies-literature

Design of Heat-Conductive hBN-PMMA Composites by Electrostatic Nano-Assembly.

Project description:Micro/nanoscale design of composite materials enables alteration of their properties for advanced functional materials. One of the biggest challenges in material design is the controlled decoration of composite materials with the desired functional additives. This study reports on and demonstrates the homogeneous decoration of hexagonal boron nitride (hBN) on poly(methylmethacrylate) (PMMA) and vice versa. The formation of the composite materials was conducted via a low environmental load and a low-energy-consuming, electrostatic nano-assembly method which also enabled the efficient usage of nano-sized additives. The hBN/PMMA and PMMA/hBN composites were fabricated in various size combinations that exhibited percolated and layer-oriented structures, respectively. The thermal conductivity behaviors of hBN/PMMA and PMMA/hBN composites that exhibited good microstructure were compared. The results showed that microstructural design of the composites enabled the modification of their heat-conducting property. This novel work demonstrated the feasibility of fabricating heat-conductive PMMA matrix composites with controlled decoration of hBN sheets, which may provide a platform for further development of heat-conductive polymeric materials.

| S-EPMC7022472 | biostudies-literature

Noble-Metal-Free Iron Nitride/Nitrogen-Doped Graphene Composite for the Oxygen Reduction Reaction.

Project description:Considerable effort has been devoted recently to replace platinum-based catalysts with their non-noble-metal counterparts in the oxygen reduction reaction (ORR) in fuel cells. Nitrogen-doped carbon structures emerged as possible candidates for this role, and their earth-abundant metal-decorated composites showed great promise. Here, we report on the simultaneous formation of nitrogen-doped graphene and iron nitride from the lyophilized mixture of graphene oxide and iron salt by high-temperature annealing in ammonia atmosphere. A mixture of FeN and Fe2N particles was formed with average particle size increasing from 23.4 to 127.0 nm and iron content ranging from 5 to 50 wt %. The electrocatalytic oxygen reduction activity was investigated via the rotating disk electrode method in alkaline media. The highest current density of 3.65 mA cm-2 at 1500 rpm rotation rate was achieved in the 20 wt % catalyst via the four-electrode reduction pathway, exceeding the activity of both the pristine iron nitride and the undecorated nitrogen-doped graphene. Since our catalysts showed improved methanol tolerance compared to the platinum-based ones, the formed non-noble-metal system offers a viable alternative to the platinum-decorated carbon black (Pt/CB) ORR catalysts in direct methanol fuel cells.

| S-EPMC6647991 | biostudies-literature

Nanostructured Iron Sulfide/N, S Dual-Doped Carbon Nanotube-Graphene Composites as Efficient Electrocatalysts for Oxygen Reduction Reaction.

Project description:Nanostructured FeS dispersed onto N, S dual-doped carbon nanotube-graphene composite support (FeS/N,S:CNT-GR) was prepared by a simple synthetic method. Annealing an ethanol slurry of Fe precursor, thiourea, carbon nanotube, and graphene oxide at 973 K under N2 atmosphere and subsequent acid treatment produced FeS nanoparticles distributed onto the N, S-doped carbon nanotube-graphene support. The synthesized FeS/N,S:CNT-GR catalyst exhibited significantly enhanced electrochemical performance in the oxygen reduction reaction (ORR) compared with bare FeS, FeS/N,S:GR, and FeS/N,S:CNT with a small half-wave potential (0.827 V) in an alkaline electrolyte. The improved ORR performance, comparable to that of commercial Pt/C, could be attributed to synergy between the small FeS nanoparticles with a high activity and the N, S-doped carbon nanotube-graphene composite support providing high electrical conductivity, large surface area, and additional active sites.

| S-EPMC8122905 | biostudies-literature

3D graphene preparation via covalent amide functionalization for efficient metal-free electrocatalysis in oxygen reduction.

Project description:3D and porous reduced graphene oxide (rGO) catalysts have been prepared with sp3-hybridized 1,4-diaminobutane (sp3-DABu, rGO-sp3-rGO) and sp2-hybridized 1,4-diaminobenzene (sp2-DABe, rGO-sp2-rGO) through a covalent amidation and have employed as a metal-free electrocatalyst for oxygen reduction reaction (ORR) in alkaline media. Both compounds have used as a junction between functionalized rGO layers to improve electrical conductivity and impart electrocatalytic activity to the ORR resulting from the interlayer charge transfer. The successful amidation and the subsequent reduction in the process of catalyst preparation have confirmed by X-ray photoelectron spectroscopy. A hierarchical porous structure is also confirmed by surface morphological analysis. Specific surface area and thermal stability have increased after successful the amidation by sp3-DABu. The investigated ORR mechanism reveals that both functionalized rGO is better ORR active than nonfunctionalized rGO due to pyridinic-like N content and rGO-sp3-rGO is better ORR active than rGO-sp2-rGO due to higher pyridinic-like N content and π-electron interaction-free interlayer charge transfer. Thus, the rGO-sp3-rGO has proven as an efficient metal-free electrocatalyst with better electrocatalytic activity, stability, and tolerance to the crossover effect than the commercially available Pt/C for ORR.

| S-EPMC5327434 | biostudies-literature

Synthesis and Characterization of Lithium-Ion Conductive LATP-LaPO4 Composites Using La2O3 Nano-Powder.

Project description:LATP-based composite electrolytes were prepared by sintering the mixtures of LATP precursor and La2O3 nano-powder. Powder X-ray diffraction and scanning electron microscopy suggest that La2O3 can react with LATP during sintering to form fine LaPO4 particles that are dispersed in the LATP matrix. The room temperature conductivity initially increases with La2O3 nano-powder addition showing the maximum of 0.69 mS∙cm-1 at 6 wt.%, above which, conductivity decreases with the introduction of La2O3. The activation energy of conductivity is not largely varied with the La2O3 content, suggesting that the conduction mechanism is essentially preserved despite LaPO4 dispersion. In comparison with the previously reported LATP-LLTO system, although some unidentified impurity slightly reduces the conductivity maximum, the fine dispersion of LaPO4 particles can be achieved in the LATP-La2O3 system.

| S-EPMC8269504 | biostudies-literature

Highly Thermally Conductive Polymer/Graphene Composites with Rapid Room-Temperature Self-Healing Capacity.

Project description:Composites that can rapidly self-healing their structure and function at room temperature have broad application prospects. However, in view of the complexity of composite structure and composition, its self-heal is facing challenges. In this article, supramolecular effect is proposed to repair the multistage structure, mechanical and thermal properties of composite materials. A stiff and tough supramolecular frameworks of 2-[[(butylamino)carbonyl]oxy]ethyl ester (PBA)-polydimethylsiloxane (PDMS) were established using a chain extender with double amide bonds in a side chain to extend prepolymers through copolymerization. Then, by introducing the copolymer into a folded graphene film (FGf), a highly thermally conductive composite of PBA-PDMS/FGf with self-healing capacity was fabricated. The ratio of crosslinking and hydrogen bonding was optimized to ensure that PBA-PDMS could completely self-heal at room temperature in 10 min. Additionally, PBA-PDMS/FGf exhibits a high tensile strength of 2.23 ± 0.15 MPa at break and high thermal conductivity of 13 ± 0.2 W m-1 K-1; of which the self-healing efficiencies were 100% and 98.65% at room temperature for tensile strength and thermal conductivity, respectively. The excellent self-healing performance comes from the efficient supramolecular interaction between polymer molecules, as well as polymer molecule and graphene. This kind of thermal conductive self-healing composite has important application prospects in the heat dissipation field of next generation electronic devices in the future.

| S-EPMC9200911 | biostudies-literature

Tunneling Conductivity and Piezoresistivity of Composites Containing Randomly Dispersed Conductive Nano-Platelets.

Project description:In this study, a three-dimensional continuum percolation model was developed based on a Monte Carlo simulation approach to investigate the percolation behavior of an electrically insulating matrix reinforced with conductive nano-platelet fillers. The conductivity behavior of composites rendered conductive by randomly dispersed conductive platelets was modeled by developing a three-dimensional finite element resistor network. Parameters related to the percolation threshold and a power-low describing the conductivity behavior were determined. The piezoresistivity behavior of conductive composites was studied employing a reoriented resistor network emulating a conductive composite subjected to mechanical strain. The effects of the governing parameters, i.e., electron tunneling distance, conductive particle aspect ratio and size effects on conductivity behavior were examined.

| S-EPMC5453361 | biostudies-other

Micro- and nano-patterned conductive graphene-PEG hybrid scaffolds for cardiac tissue engineering.

Project description:A lack of electrical conductivity and structural organization in currently available biomaterial scaffolds limits their utility for generating physiologically representative models of functional cardiac tissue. Here we report on the development of scalable, graphene-functionalized topographies with anisotropic electrical conductivity for engineering the structural and functional phenotypes of macroscopic cardiac tissue constructs. Guided by anisotropic electroconductive and topographic cues, the tissue constructs displayed structural property enhancement in myofibrils and sarcomeres, and exhibited significant increases in the expression of cell-cell coupling and calcium handling proteins, as well as in action potential duration and peak calcium release.

| S-EPMC5548490 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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