Search results for " Graphene"
showing 10 items of 102 documents
Electron-electron interactions in artificial graphene
2012
Recent advances in the creation and modulation of graphenelike systems are introducing a science of ``designer Dirac materials''. In its original definition, artificial graphene is a man-made nanostructure that consists of identical potential wells (quantum dots) arranged in an adjustable honeycomb lattice in the two-dimensional electron gas. As our ability to control the quality of artificial graphene samples improves, so grows the need for an accurate theory of its electronic properties, including the effects of electron-electron interactions. Here we determine those effects on the band structure and on the emergence of Dirac points.
AB Initio Calculations of CUN@Graphene (0001) Nanostructures for Electrocatalytic Applications
2018
Funding from European Union’s Horizon 2020 Research and Innovation Programme project under grant agreement No. 768789 is greatly acknowledged.
Electrochemical biosensing using N-GQDs: Recent advances in analytical approach
2018
Abstract This review is meant to provide an overview of the electrochemical biosensors based on Nitrogen doped graphene quantum dots (N-GQDs) for analytical approaches, along with significant advances over the last several years in related technologies. In addition, this review described: i) Most frequently applied principles in biosensing based on of N-GQDs ii) The aspects of fabrication in the perspective of biosensing applications iii) The potential of various electrochemical, biosensors for the determination of target analytes within sub-micromolar range and the circumvention of the most serious problem in biosensing will be discussed. iv) Some of multiplex electrochemical biosensors ha…
RETRACTED: Optical bio(sensing) using nitrogen doped graphene quantum dots: Recent advances and future challenges
2018
Abstract The exceptional optical properties and the presence of high number of reactive sites make nitrogen doped graphene quantum dots (N-GQDs) powerful tools in analytical nanoscience and nanotechnology. At the same time, their opto-electronics properties make them excellent nanomaterials for biomedical analysis aspects. This review aims to explore progress to date various features of N-GQDs for optical bio (sensing) of target analytes. Moreover, as another aim of this review is to provide insight into the intensity based spectroscopic methods which are applied in bio (sensing) discussing their advantages and disadvantages. More importantly, we discuss in detail different aspects of the a…
PHOTO-OXIDATION OF PA6/GRAPHENE OXIDE FILMS
2014
Graphene oxide (GrO) was synthesized with Marcano’s method [1] and added at 0.5 and 1 wt% loading content to a polyamide 6 (PA6). In particular, three different techniques have been used for the preparation of the nanocomposites: (i) melt blending in a batch mixer, (ii) solvent casting in formic acid, (iii) preparation of a masterbatch by solvent casting and further melt processing. The films (80 m) were photo-oxidized in a QU-V chamber up to about 100 hours. The effect of filler content and preparation technique on the photo-stability of the nanocomposites has been followed by monitoring the change of the mechanical and spectroscopic properties undergone upon artificial exposure to UV-B l…
Modification of Structural and Luminescence Properties of Graphene Quantum Dots by Gamma Irradiation and Their Application in a Photodynamic Therapy
2015
Herein, the ability of gamma irradiation to enhance the photoluminescence properties of graphene quantum dots (GQDs) was investigated. Different doses of gamma-irradiation were used on GQDs to examine the way in which their structure and optical properties can be affected. The photoluminescence quantum yield was increased six times for the GQDs irradiated with high doses compared to the nonirradiated material. Both photoluminescence lifetime and values of optical band gap were increased with the dose of applied gamma irradiation. In addition, the exploitation of the gamma-irradiated GQDs as photosensitizers was examined by monitoring the production of singlet oxygen under UV illumination. T…
Study of ordered hadron chains with the ATLAS detector
2017
The analysis of the momentum difference between charged hadrons in high-energy proton-proton collisions is performed in order to study coherent particle production. The observed correlation pattern agrees with a model of a helical QCD string fragmenting into a chain of ground-state hadrons. A threshold momentum difference in the production of adjacent pairs of charged hadrons is observed, in agreement with model predictions. The presence of low-mass hadron chains also explains the emergence of charge-combination-dependent two-particle correlations commonly attributed to Bose-Einstein interference. The data sample consists of 190 μb-1 of minimum-bias events collected with proton-proton colli…
Bilayer graphene lattice-layer entanglement in the presence of non-Markovian phase noise
2018
The evolution of single particle excitations of bilayer graphene under effects of non-Markovian noise is described with focus on the decoherence process of lattice-layer (LL) maximally entangled states. Once that the noiseless dynamics of an arbitrary initial state is identified by the correspondence between the tight-binding Hamiltonian for the AB-stacked bilayer graphene and the Dirac equation -- which includes pseudovector- and tensor-like field interactions -- the noisy environment is described as random fluctuations on bias voltage and mass terms. The inclusion of noisy dynamics reproduces the Ornstein-Uhlenbeck processes: a non-Markovian noise model with a well-defined Markovian limit…
Robust Two-Dimensional Electronic Properties in Three-Dimensional Microstructures of Rotationally Stacked Turbostratic Graphene
2017
We report on the electronic properties of turbostratic graphitic microdisks, rotationally stacked systems of graphene layers, where interlayer twisting leads to electronic decoupling resulting in charge-transport properties that retain the two dimensionality of graphene, despite the presence of a large number of layers. A key fingerprint of this reduced dimensionality is the effect of weak charge-carrier localization that we observe at low temperatures. The disks' resistivity measured as a function of magnetic field changes its shape from parabolic at room temperature to linear at a temperature of 2.7 K indicating further this type of two-dimensional transport. Compared to Bernal stacked gr…
C3N4/reduced graphene oxide photocatalysts loaded with Ag or Ag/Pt for H2 evolution from aqueous solution of triethanolamine
2023
Composites of C3N4/reduced graphene oxide have been used as photocatalysts for triethanolamine photo- reforming with H2 generation in aqueous solution. The rate of H2 production over the Ag loaded best per- forming photocatalyst reached 525 μmol⋅h