scispace - formally typeset
Search or ask a question

Answers from top 10 papers

More filters
Papers (10)Insight
This paper reports a novel universal method to grow and etch graphene film using a one-step laser-scribing process.
Herein, we demonstrate a facile and scalable chemical vapor deposition approach to synthesize meter-sized super-clean graphene with an average cleanness of 99%, relying on the weak oxidizing ability of CO2 to etch away the intrinsic contamination, i. e., amorphous carbon.
These reports show that metallic nanoparticles etch the surface layers of graphite or graphene anisotropically along the crystallographic zig-zag ‹11-20› or armchair ‹10-10› directions.
Graphene etch stops enable one-step patterning of sophisticated devices from heterostructures by accessing buried layers and forming one-dimensional contacts.
Here we demonstrate an atomically thin graphene etch stop for patterning van der Waals heterostructures through the selective etch of two-dimensional materials with xenon difluoride gas.
Here, we show that graphene origami is an efficient way to convert graphene into atomically precise, complex nanostructures.
Graphene hydrogenation is an attractive approach to functionalize graphene.
By using a self-aligned contact method during device fabrication, we can skip the dry-etch process which requires an exact etch-stop at the surface of the graphene layer and is not easy to control.
It is possible to build graphene-based electronic circuits from graphene hydroxide without the need for cutting or etching.
Electron-beam induced deposition on graphene might be used to create nanometer-scale doping patterns, diffraction gratings, or etch masks in this novel electronic material.

Related Questions

How to etch HfO2 by atomic layer etching?3 answersHfO2 can be etched by atomic layer etching (ALE) using different methods. One approach involves surface modification by fluorocarbon film deposition followed by activation of etching through Ar ion bombardment. Another method involves exposure to atomic hydrogen beams, which leads to the formation of a volatile hafnium dihydroxide and allows for precise control of the etching conditions. A selective ALE process for HfO2 can be achieved by combining substrate-selective deposition with etching using a CH4/CHF3 mixture. Additionally, thermal ALE using HF and TiCl4 as reactants has been studied, showing self-limiting etching of HfO2 films. The etching selectivity can be explained by the reaction thermochemistry and the stability and volatility of the possible etch products.
How to etch SnO2 by atomic layer etching?5 answersSnO2 can be etched by atomic layer etching (ALE) using fluorine-based etching processes. Tin forms nonvolatile compounds with fluorine at process temperatures, allowing it to function as an etch mask. In ALE, the substrate is alternately exposed to a first vapor phase non-metal halide reactant (e.g., fluorinating gas) and a second vapor phase halide reactant (e.g., chlorinating gas). The ALE process cycle includes forming an adsorption monolayer of the etchant on the substrate, purging the excess etchant, desorbing the adsorption monolayer by exposing it to gas ions, and purging the system again. To etch SnO2, one can use SF6 reactive ion etching (RIE) with SnO2 as the etch mask. Grid patterns can be transferred into Si(001) using SF6 RIE when a certain number of atomic layer deposition (ALD) cycles of SnO2 are grown.
What are the problems with over-etching during Mxene synthesis?4 answersOver-etching during MXene synthesis can lead to several problems. One issue is the subsequent formation of carbide-derived carbon (CDC). This over-etching of the parent MAX phases can result in the formation of CDC instead of MXene. Another problem is the introduction of defects in the MXene material. The presence of aluminum and the unsuccessful removal of AlF3 by-products can lead to the presence of defects in the MXene layers. Additionally, over-etching can increase the fluorine content in the MXene, which can lead to an increase in the number of defects in the material. These problems highlight the importance of carefully balancing the etching parameters to avoid over-etching and ensure the production of high-quality MXene materials.
What are the factors that affect the etching time of MXene?3 answersThe factors that affect the etching time of MXene include the type and concentration of the etchant, the temperature of the etching process, and the particle size of the MAX phase precursor. Different fluoride-based salts, such as lithium fluoride (LiF) and ammonium fluoride (NH4F), have been used as etchants for MXene synthesis. NH4HF2 has been found to be the most efficient etchant, reducing the etching time to a few hours. The concentration of the etchant also plays a role, with optimal concentrations of LiF at 5M and NH4F at 3M. The temperature of the etching process is another important factor, with room temperature being the optimum due to the exothermic reaction involved. Additionally, the particle size of the MAX phase precursor can influence the etching kinetics, with narrow fractions of particle sizes yielding better results.
How do you prepare graphene coating?10 answers
How to mold graphene?10 answers

See what other people are reading

How does the presence of Fe3O4 affect the kinetics of PDA formation?
5 answers
The presence of Fe3O4 influences the kinetics of polydopamine (PDA) formation by aiding in the quick separation of the substrate from solutions, simplifying the detection process, and facilitating substrate reuse. Fe3O4@PDA@GDH nanoparticles, for instance, demonstrated efficient glycerol dehydrogenation due to the polydopamine-coated Fe3O4 nanoplatform. Additionally, Fe3O4@PDA-TLL nanobiocatalysts showed successful immobilization of Thermomyces lanuginosus lipase, leading to regioselective acylation reactions with high conversion rates and stability. Fe3O4@PDA core–shell nanoparticles were also effective in removing Pb(II) and Cu(II) from wastewater due to the versatile PDA layer's functional groups, indicating fast removal kinetics and high adsorption capacities. Overall, the presence of Fe3O4 in various nanocomposites significantly impacts the kinetics and efficiency of PDA formation and subsequent catalytic or adsorption processes.
Why graphene oxide should be chosen over reduced graphene oxide in photocatalytic activity?
5 answers
Graphene oxide should be chosen over reduced graphene oxide in photocatalytic activity due to its superior properties. Graphene oxide-based photocatalysts exhibit enhanced performance in CO2 reduction, thanks to their excellent physical and chemical characteristics and strong π–π conjugation with CO2 molecules. Furthermore, in the context of nanocomposite materials, the concentration of graphene oxide plays a crucial role in increasing the efficiency of the material, with a 7 wt% concentration showing significant improvements in photocurrent and absorption ability. Additionally, TiO2-RGO composites have demonstrated better degradation rates for various dyes compared to TiO2 alone, attributed to graphene's strong electron transport ability and adsorption properties. These findings collectively highlight the importance of graphene oxide in enhancing photocatalytic activities in various applications.
Durian seed as a chalk?
4 answers
Durian seed has been explored for various applications, but using it as chalk is not a common practice based on the available research. Studies have highlighted the potential of durian seed gum as an excipient in topical drug delivery, as a substrate for angkak production, and for the removal of dyes from aqueous solutions. Additionally, durian seed has been utilized in the synthesis of a durian-like mischcrystal TiO2/graphene photocatalyst for desulfurization. While durian seed has shown promise in diverse applications, there is no specific mention of its use as chalk in the existing literature. Further research may be needed to explore the feasibility and effectiveness of utilizing durian seed for chalk production.
What the methods for fabrication of carbon electrodes using silicon wafers?
5 answers
The fabrication methods for carbon electrodes using silicon wafers involve several key steps. Initially, a mixture containing a precursor, silicon particles, and carbon fibers is provided on a current collector, followed by pyrolysis to convert the precursor into carbon phases, forming a composite material adhered to the current collector. Another approach includes forming a composite material film by providing a mixture with a precursor and silane-treated silicon particles, then pyrolyzing the mixture to create the composite material film with distributed silicon particles. Additionally, a method entails coating a current collector with a slurry containing silicon particles, polymeric binders, and carbon fibers, followed by pyrolysis at specific temperatures to produce an electrode with a silicon-based host material layer. These methods collectively contribute to the efficient fabrication of carbon electrodes using silicon-based materials.
What is the relationship between the amount of incident light and the catalytic properties of Cu2O?
5 answers
The relationship between the amount of incident light and the catalytic properties of Cu2O nanoparticles is crucial for understanding their photocatalytic efficiency. Studies have shown that Cu2O nanoparticles with different shapes and sizes exhibit varying photocatalytic activities under different light intensities. Specifically, Cu2O crystals with irregular but thick platelet-like shapes and small granule spheres showed enhanced photocatalytic activity. Additionally, decorating Cu2O nanooctahedra with small Au nanograins improved the photocatalytic activity even under low-power excitation. Furthermore, Cu2O nanostructures exhibiting dielectric Mie resonances demonstrated significantly higher photocatalytic rates compared to those without, showing a relationship between the size of Cu2O nanospheres and nanocubes and their photocatalytic efficiency. These findings highlight the importance of incident light intensity in modulating the catalytic properties of Cu2O nanoparticles.
Stair free contact 공정 개선을 위한 Photolithography의 역할은 뭔가요?
5 answers
Photolithography plays a crucial role in improving the stair-free contact process by enabling precise patterning of materials. Stair-stepping issues, common in rapid prototyping systems, can be addressed through innovative scanning techniques like slant beam rotation (SBR) scanning, which reduces surface roughness significantly. Additionally, advancements in lithographic techniques, such as creating borderless contact holes using multiple layers of dielectric with different etch rates, contribute to enhancing contact processes. By incorporating these techniques, the efficiency and reliability of the contact process can be improved, reducing time consumption for position exchange and enhancing system performance. Overall, photolithography plays a pivotal role in enabling precise and efficient fabrication processes essential for achieving stair-free contacts in various applications.
How does the wavelength of incident light affect the rate of catalysis in Cu2O?
5 answers
The wavelength of incident light significantly influences the rate of catalysis in Cu2O. Cu2O nanoparticles have been studied for their photocatalytic properties, especially in dye degradation processes. Different wavelengths of light, such as green, blue, red, and amber, have been utilized to selectively degrade methylene blue dye peaks through Mie resonance mediated photocatalysis using Cu2O as a catalyst. Additionally, Cu2O/TNA/Ti junctions have shown higher photocurrent spectral responses due to the UV-visible light absorption of Cu2O, leading to improved photocatalytic properties compared to other junctions. Moreover, the absorption range of Cu2O/ZnO catalysts shifts from ultraviolet to visible light due to the doping of Cu2O, enhancing the degradation efficiency of methyl orange solution under visible light.
What is the specific capacitance for double layer capacity on carbon nanotubes?
4 answers
The specific capacitance for electric double-layer capacitors (EDLCs) on carbon nanotubes varies depending on the specific surface area and the synthesis method. Studies have shown that different types of carbon nanotubes, such as vertically-aligned (VA) and laterally-aligned (LA) CNTs, exhibit specific capacitances ranging from 1.5 mF cm−2 to 25-75 F/g. Additionally, the incorporation of graphene/carbon nanotube nanocomposites in EDLC electrodes has demonstrated specific capacitances of 15.5 F cc−1. Furthermore, utilizing multiwalled carbon nanotubes in combination with nano silica dispersed in a gel polymer electrolyte has shown a specific capacitance of 92 mF cm−2, equivalent to 92 F g−1. These findings highlight the potential of carbon nanotubes in enhancing the specific capacitance of EDLCs, offering promising advancements in energy storage technology.
What is the uF cm-2 for double layer capacity on carbon nanotubes?
5 answers
The double-layer capacity on carbon nanotubes (CNTs) varies based on the specific type and structure. Research has shown that vertically-aligned CNTs (VACNTs) grown on graphite surfaces exhibit the highest electrostatic capacity of 1.5 mF cm−2 among different CNT configurations, such as laterally-aligned CNTs (LACNTs) and pristine graphite. Additionally, Single Walled Carbon Nanotubes (SWCNTs) used as active materials in supercapacitors have shown specific capacitance in the range of 40-45 F/g. Furthermore, the combination of graphene flakes and carbon nanotubes in EDLC electrodes has demonstrated high active material mass loadings up to around 30 mg cm-2, resulting in excellent electrode energy densities and operating power densities.
How does the use of boron catalysts affect the efficiency of methane oxidation?
5 answers
The use of boron-based catalysts, such as hexagonal BN (h-BN) and boron-doped carbon materials, significantly impacts the efficiency of methane oxidation. Boron catalysts exhibit high selectivity towards valuable products like formaldehyde and propylene. These catalysts act as radical generators, inducing gas-phase radical reactions of methane oxidation, leading to improved selectivity and anti-overoxidation ability. Boron peroxo species on the catalyst surface play a crucial role in dehydrogenating propane, favoring propene formation over deep oxidation. Boron oxide (B2O3) has shown reactivity towards dioxygen for methane activation, with mechanistic pathways leading to formaldehyde production. Overall, boron catalysts enhance methane oxidation efficiency by promoting selective oxidation pathways and providing active sites for radical reactions.
Can E.coli take other forms other than rod shape?
4 answers
Yes, Escherichia coli (E. coli) can take other forms besides the rod shape. Filamentous growth, where E. coli elongates into long thin shapes called filaments, has been observed in certain conditions. These filaments are thought to be advantageous for the bacteria during infections as they are too long to be engulfed and killed by immune cells called macrophages. Additionally, pleomorphic varieties of E. coli, which exhibit aberrant morphological variations, have been observed. These pleomorphic forms can include spherical or cell wall-deficient protoplasmic states. The acquisition of these aberrant morphological variations can be a phenotypic manifestation of antibiotic resistance and adaptation to toxic environments. Therefore, E. coli has the ability to exhibit different forms beyond the typical rod shape.