scholarly journals Bandgap Engineering in Iron Doped Graphene Nanosheets: Electrical Performance Boosting for Application in Nano-electronics 

2020 ◽  
Author(s):  
Swarnava Biswas ◽  
Debajit Sen ◽  
Moumita Mukherjee
Keyword(s):  
Electrical Properties ◽  
Graphene Nanosheets ◽  
Electrical Performance ◽  
Pristine Graphene ◽  
Iron Doping ◽  
Bandgap Engineering ◽  
Graphene Nanosheet ◽  
Potential Measurement ◽  
Energy Value ◽  
Doped Graphene

The study reports electrical properties of iron atom doped graphene nanosheets using Atomistix Tool Kit- Virtual NanoLab (ATK-VNL) QuantumWise simulation package. Density Function Theory (DFT) has been adopted for the present study. The introduction of iron atoms in a bare graphene nanosheet make changes in the band-structure of otherwise perfectly overlapped bandgap of pristine graphene nanosheets. The controlled amount of iron doping opens a small bandgap in graphene and that enhances gradually with further increase of doping concentration. Chemical potential measurement indicates a steady increase in the magnitude from - 5.661314 eV to - 5.910896 eV. The study depicts that the pristine graphene nanosheet exhibits a DOS value of ~330 eV-1 at energy value ~12 eV, but in case of its doped counterpart, the DOS values change to ~290 eV-1, ~270 eV-1 and ~250 eV-1 respectively for one, two and three atoms doped graphene nanosheets at a specific energy value of ~12 eV. The paper will address the total energy and transmission spectrum of bare and doped graphene nanosheets. The role of iron dopant in tuning the electrical properties of graphene nanosheets are studied extensively for application in nano-electronics. To the best of authors knowledge this is the first report on bandgap engineering in graphene nanosheets by controlled iron doping.

scholarly journals Investigation of the Effect of 3d TM-TM Atom Co-Doped in Graphene Nanosheet: DFT Based Calculations

2021 ◽  
pp. 122-132
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Graphene Nanosheets ◽  
Single Point ◽  
Magnetic Behavior ◽  
Pristine Graphene ◽  
Graphene Nanosheet ◽  
Metallic Behavior ◽  
Doped Graphene ◽  
Co Doped

Graphene, an interesting 2D system has a rare electronic structure of two inverted Dirac cones touching at a single point, with great electron mobility and promising microelectronics applications. In the present article, a theoretical investigation has been performed on the structural, electronic, and magnetic properties of pristine graphene nanosheet and also the effect of 3d transition metal (TM) co-doped in graphene nanosheet within the density functional theory framework. 3d TM is categorized into two groups: Cr- group (Cr-Cr, Cr-Mn, and Cr-Fe) and Ni-group (Ni-Cr, Ni-Ti, Ni-Mn). After co-doping TM atoms on graphene, it still holds its planar shape which refers to the stability of these co-doped graphene nanosheets. This is also confirmed by the increasing bond length of carbon and TM atoms on graphene nanosheets. Highest zero-point energies have been found of -12049.24eV and -10936.87eV respectively for Cr-Cr and Ni-Cr co-doped graphene nanosheet. According to Mulliken's charge and electron density differences, all the TM atoms can act as electron donors while the graphene nanosheet is electron acceptor. All the TMs co-doped graphene nanosheet show metallic behavior in terms of band structures and DOS plots except Ti-Ni which has shown a little band gap. In terms of electronic properties, Cr-Cr and Ni-Cr co-doped graphene nanosheets are found most stable among the other studied systems and they can exhibit magnetic behavior as there is a variation in their up and down spin as shown in spin polarized DOS. That’s why they are beneficial to the application of various magnetic devices as well as sectors. Besides Cr-group co-doped graphene nanosheet can exhibit better magnetic properties than Ni-group.

scholarly journals CO Tolerance and Stability of Graphene and N-Doped Graphene Supported Pt Anode Electrocatalysts for Polymer Electrolyte Membrane Fuel Cells

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 597
Author(s):  
Martin González-Hernández ◽  
Ermete Antolini ◽  
Joelma Perez
Keyword(s):  
Fuel Cells ◽  
Polymer Electrolyte ◽  
Graphene Nanosheets ◽  
Polymer Electrolyte Membrane ◽  
Co Adsorption ◽  
Active Surface Area ◽  
Pristine Graphene ◽  
Electrolyte Membrane ◽  
Co Tolerance ◽  
Doped Graphene

Pt electrocatalysts supported on pristine graphene nanosheets (GNS) and nitrogen-doped graphene nanoplatelets (N-GNP) were prepared through the ethylene glycol process, and a comparison of their CO tolerance and stability as anode materials in polymer electrolyte membrane fuel cells (PEMFCs) with those of the conventional carbon (C)-supported Pt was made. Repetitive potential cycling in a half cell showed that Pt/GNS catalysts have the highest stability, in terms of the highest sintering resistance (lowest particle growth) and the lowest electrochemically active surface area loss. By tests in PEMFCs, the Pt/N-GNP catalyst showed the highest CO tolerance, while the poisoning resistance of Pt/GNS was lower than that of Pt/C. The higher CO tolerance of Pt/N-GNP than that of Pt/GNS was ascribed to the presence of a defect in graphene, generated by N-doping, decreasing CO adsorption energy.

Chemiresistive gas sensor for the sensitive detection of nitrogen dioxide based on nitrogen doped graphene nanosheets

RSC Advances ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 1527-1534 ◽  
Author(s):  
Mahabul Shaik ◽  
V. K. Rao ◽  
Manish Gupta ◽  
K. S. R. C. Murthy ◽  
Rajeev Jain
Keyword(s):  
Nitrogen Dioxide ◽  
Gas Sensor ◽  
Room Temperature ◽  
Graphene Nanosheets ◽  
Sensitive Detection ◽  
Graphene Nanosheet ◽  
Interdigitated Electrodes ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Nitrogen doped graphene nanosheet coated interdigitated electrodes for sensitive detection of NO2 gas at room temperature.

scholarly journals Highly porous N-doped graphene nanosheets for rapid removal of heavy metals from water by capacitive deionization

2017 ◽  
Vol 53 (5) ◽  
pp. 881-884 ◽  
Author(s):  
Lianjun Liu ◽  
Xiaoru Guo ◽  
Rebecca Tallon ◽  
Xingkang Huang ◽  
Junhong Chen
Keyword(s):  
Heavy Metals ◽  
Graphene Nanosheets ◽  
Capacitive Deionization ◽  
Efficient Removal ◽  
Graphene Nanosheet ◽  
Removal Of Heavy Metals ◽  
Doped Graphene ◽  
Rapid Removal ◽  
Multiple Heavy Metals ◽  
Highly Porous

Highly porous N-doped graphene nanosheet-based capacitive deionization for rapid and efficient removal of multiple heavy metals from water.

A DFT Study of CO and NO Adsorptions on AlN-, AlP-, and ZnO-doped Graphene Nanosheets

2016 ◽  
Vol 230 (2) ◽  
Author(s):  
Niwat Promthong ◽  
Nadtanet Nunthaboot ◽  
Wanno Banchob
Keyword(s):  
Density Functional ◽  
Gas Adsorption ◽  
Graphene Nanosheets ◽  
Nitrogen Monoxide ◽  
Density Functional Theory Calculations ◽  
Pristine Graphene ◽  
Functional Theory ◽  
Co Doping ◽  
Doped Graphene ◽  
Co Doped

AbstractDensity functional theory calculations were performed to investigate the adsorption abilities of carbon monoxide (CO) and nitrogen monoxide (NO) gas molecules onto pristine graphene nanosheet (GNS), and AlN-, AlP-, and ZnO-doped GNSs. The co-doping of AlN, AlP, and ZnO onto GNS can improve the CO and NO adsorption abilities of GNS. The gas adsorption abilities on the pristine and co-doped GNSs were determined to be, in decreasing order: ZnO-GNS ∼ AlP-GNS > AlN-GNS > pristine GNSs and AlP-GNS > AlN-GNS > ZnO-GNS > pristine GNSs for the adsorptions of CO and NO, respectively. These newly developed co-doped GNSs could be candidates for CO and NO gas storages. The adsorption geometries, adsorption energies, density of states, and charge transfers were also reported.

scholarly journals N-doped graphene foam obtained by microwave-assisted exfoliation of graphite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malgorzata Skorupska ◽  
Anna Ilnicka ◽  
Jerzy P. Lukaszewicz
Keyword(s):  
Electron Microscopy ◽  
Electrode Materials ◽  
Elemental Content ◽  
Research Approach ◽  
Pristine Graphene ◽  
Active Electrode ◽  
Graphene Foam ◽  
Practical Applications ◽  
Microwave Reactor ◽  
Doped Graphene

AbstractThe synthesis of metal-free but electrochemically active electrode materials, which could be an important contributor to environmental protection, is the key motivation for this research approach. The progress of graphene material science in recent decades has contributed to the further development of nanotechnology and material engineering. Due to the unique properties of graphene materials, they have found many practical applications: among others, as catalysts in metal-air batteries, supercapacitors, or fuel cells. In order to create an economical and efficient material for energy production and storage applications, researchers focused on the introduction of additional heteroatoms to the graphene structure. As solutions for functionalizing pristine graphene structures are very difficult to implement, this article presents a facile method of preparing nitrogen-doped graphene foam in a microwave reactor. The influence of solvent type and microwave reactor holding time was investigated. To characterize the elemental content and structural properties of the obtained N-doped graphene materials, methods such as elemental analysis, high-resolution transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy were used. Electrochemical activity in ORR of the obtained materials was tested using cyclic voltamperometry (CV) and linear sweep voltamperometry (LSV). The tests proved the materials’ high activity towards ORR, with the number of electrons reaching 3.46 for tested non-Pt materials, while the analogous value for the C-Pt (20 wt% loading) reference was 4.

scholarly journals An Investigation of the Physical and Electrical Properties of Knitted Electrodes When Subjected to Multi-Axial Compression and Abrasion

Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 2
Author(s):  
Arash M. Shahidi ◽  
Theodore Hughes-Riley ◽  
Carlos Oliveira ◽  
Tilak Dias
Keyword(s):  
Heart Rate ◽  
Electrical Properties ◽  
Applied Load ◽  
Pressure Sensors ◽  
Electrical Performance ◽  
Electronic Textiles ◽  
Heart Rate Monitors ◽  
Mechanical Loads ◽  
And Performance ◽  
Over Time

Knitted electrodes are a key component to many electronic textiles including sensing devices, such as pressure sensors and heart rate monitors; therefore, it is essential to assess the electrical performance of these knitted electrodes under different mechanical loads to understand their performance during use. The electrical properties of the electrodes could change while deforming, due to an applied load, which could occur in the uniaxial direction (while stretched) or multiaxial direction (while compressed). The properties and performance of the electrodes could also change over time when rubbed against another surface due to the frictional force and generated heat. This work investigates the behavior of a knitted electrode under different loading conditions and after multiple abrasion cycles.

Optimum Design of Inductors Used for Wireless Power Transmission Micro-Module

2004 ◽  
Author(s):  
Chao-Liang Chang ◽  
Uei-Ming Jow ◽  
Chao-Ta Huang ◽  
Hsiang-Chi Liu ◽  
Jr-Yuan Jeng ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Electrical Properties ◽  
Optimum Design ◽  
Thermal Loading ◽  
Power Transmission ◽  
Thermal Strain ◽  
Electrical Performance ◽  
Wireless Power ◽  
Wireless Power Transmission ◽  
Analysis Software

The micro-inductor is a key component in wireless power transmission micro modules. In this paper, an optimum design for the micro-inductor was studied and related MEMS fabrication techniques were also developed. Commercial electromagnetic property analysis software, ANSOFT, was used to screen the main design factors of the micro-inductor. It was found that the high inductance and high quality factors of the micro-inductor implied high power transmission efficiency for the micro-module’s wireless power transmission. The electrical performance of the micro-inductor was affected by the thermal stress and thermal strain induced in the operational environment of the wireless power transmission micro-module. In order to investigate the reliability of the micro-inductor, commercial stress analysis software, ANSYS, was used to calculate thermal stress and thermal strain. The deformed model of the micro-inductor was then imported into ANSOFT in order to calculate its electrical properties. Glass substrate Pyrex 7740 was used to reduce the substrate loss of the magnetic flux of the micro-inductor. The surface micromachining technique, a kind of MEMS processing, was chosen to fabricate the micro-inductor; the coil of the micro-inductor was electroplated with copper to reduce the series resistance. The minimum line width and line space of the coil were 20 μm and 20 μm respectively. Polyimide (PI) was used for supporting the structure of micro-inductors. The maximum shear stress was 74.09MPa and the maximum warpage was 2.197 μm at a thermal loading of 125°C. For the simulated data, the most suitable areas for 31-turn and 48-turn coils were at an area ratio of 1.27 and 2, respectively. The electrical properties of the inductors changed slightly under thermal loading.

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