Nitrogen-doped graphene showed a high electrocatalytic activity

Because graphene is no bandgap, making its conductivity is not the same as a conventional semiconductor completely controlled, and the graphene surface smooth and inert, is not conducive to the composite and other materials, thus impeding the application of graphene.

Hetero atom doping is another effective method for graphene biosensor to improve performance, in which the nitrogen atom in the regulation of carbon-doped material electronic properties play an important role. Scientists graphene nitrogen plasma treatment to prepare nitrogen-doped graphene, this nitrogen-doped graphene reduction of H2O2 showed a high electrocatalytic activity, and to achieve a rapid GOx of direct electron transfer. Nitrogen-doped graphene bandgap can open and adjust the conductivity type, change the electronic structure of graphene to improve the free carrier density graphene to improve conductivity and stability of graphene, in addition, graphene carbon network Introduced nitrogen atom lattice structure, can increase the graphene surface adsorption active sites of the metal particles, thereby enhancing the interaction between the metal particles and graphene.

The role of nitrogen-doped graphene can be introduced in a carbon grid nitrogen-containing functional groups, these functional groups can become active adsorption of metal particles, thereby enhancing the interaction between the metal and the graphene, they can make graphene performance greatly improved, resulting in wide range of applications. Especially as the use of lithium ion batteries, lithium-air battery and supercapacitor electrode materials and fuel cell oxygen reduction catalysts and other new energy materials. In the lithium-ion batteries by doping nitrogen in graphene can throw maintain a high irreversible capacity, etc. at a high charge and discharge rate.

Nitrogen-doped graphene has a high oxygen reduction activity under alkaline conditions. In alkaline fuel cell test found in a wide voltage range of the steady-state catalytic current nitrogen doped graphene electrode is 5 times that of conventional electrodes and a more long-term stability.

In addition, the electrode material can also be used graphene ultracapacitors and other nitrogen doping.

 

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Graphene “King of the material” will Shake the World

Graphene is a single layer of carbon atoms in a two-dimensional structure of the material, it is not only the world’s strongest, hardest, thinnest substance, and because it is aware of the material resistivity minimum, the highest thermal conductivity and, therefore, Ideally electrode and the semiconductor material is considered to lead to revolutionary modern electronic technology and information technology.

Graphene is harder than diamond, with a hundred times of tougher than the best steel in the world so that scientists want to use it for preparing coveted “space elevator” super tough cable. 2020, graphene global market capitalization $ 149 million. Graphene’s future depends on our ability to provide high-end basic materials.

How will the “King Materials” subvert the world

Most people’s experience of using pencil writing on paper is that traces of graphite layers peeled off, when stripped to the minimum limit is only one carbon atom thick single layer of graphite, which is graphene. Surprisingly, this seemingly ordinary matter, because by two University of Manchester scientists Andre Geim and Konstantin Novoselov shared the discovery after the 2010 Nobel Prize in Physics, Since then, it seems that it opens a world of new materials, “Alibaba” door.

“It is the thinnest, the largest stenght of the mechanical material discovered in nature, which can be infinitely stretched, bent to a large angle is not broken, you can also resist very high pressures.” Nobel Laureate Professor Heim said to the reporters.

Graphene is harder than diamond, with a hundred times of tougher than the best steel in the world so scientists want to use it for preparing coveted “space elevator” super tough cable. It stabilizes the lattice structure of the carbon atoms has excellent electrical conductivity, excellent light transmission and a relatively high mechanical strength.

What will be the future development trend of graphene

Many people worry that the year will be like graphene nanomaterials first appeared as yet what the product, the concept of speculation on the fly, reducing the industry credibility; and fear as the photovoltaic industry, as many companies rush optimistic until excess production.

The Chinese Academy of Sciences, and Prof. Dr. Liu Zhongfan Molecular Engineering, Peking University chemistry in an interview with Science and Technology Daily reporter interview that “Graphene is not a very low threshold for the industry! Not everyone can enter, it is technically demanding.” We can say that this is a potential infinite but high-risk industries.

He said: “The current people talk about the future of graphene is still at relatively vague concept, its future development trend, there are three expectations, and with reference to describe the three: the first one is expected silicon, leaving the silicon chip, there is no , while the body of the information society is the chip; the second is a carbon fiber dominate the market in a particular field, such as Toray carbon fiber monopoly for defense; third is plastic, has a hundred years of development history, in people’s lives essential. so, for us, the development of minimum standards graphene is a carbon fiber, in the end, such as plastic, silicon is the highest standard, but this possibility is not known how much. ”

Winning future high-end research

Liu Zhongfan told reporters, “There is no future with graphene, graphene can depend on what made this material, we can provide the base material for high-end. Draw an analogy, you first need to make clothes of high quality cloth we strive to make the best cloth carbon fibers label, graphene material in the future there will be a label, if the former can do 10 years, then, the latter can do for 30 years. What need to do ideal thing is to do like the carbon fiber in Japan technically do dominate the global market. ”

Liu Zhongfan stressed that no carbon fiber graphene wide range of applications, if able to grasp the key graphene, I believe the future is ours. Everyone no doubt that the application of graphene in the future will develop more rapidly, then when who made high-end applications for graphene materials, who is the boss!

Is graphene’s Spring coming?

Held in Qingdao “2015 China International graphene Innovation Conference” drop curtain on the occasion, President of the European graphene flagship program of the Executive Committee, Professor Andrea Ferrari of Cambridge University Graphene Research Center founder and director of the Science and Technology Daily reporter interviewed told when excitedly said that the development in China found that graphene is very fast, last year, only to see a lot of production of graphene material, and this year actually saw related products, such as science and technology development, and manufacturing ene Wang graphene intelligent physiotherapy care waist and fever clothes.

As some experts put it, “graphene spring came not over, and the interpretation of its industrialization is still too early, but the ambience of the spring has come,” can be described as graphene from the outset, along with the question, doubt, combat, and grow, and it’s a skill like pregnant “black gold” will eventually glowing.

Carbon Nanotubes and Conductive Polymer Composites Reinforced composites

Use of carbon nanotubes with good conductivity properties, it can be used as a cathode or instead of the conductive polymer material as a conductive medium to produce high energy miniature batteries. These high energy miniature batteries will not only small, high energy, and life is very long, is used as a portable computer’s power supply and automotive electronic ignition best choice.

If pressed into sheets and carbon nanotubes as a capacitor plate, it can be made into high-energy capacitor. The small amount of carbon nanotubes added to other materials, but also can significantly improve the conductive material, for example, adding a certain amount of carbon nanotubes in the polymer material, polymer material can make the resistivity decreases three orders of magnitude.

Carbon nanotube reinforced composite material using the properties of carbon nanotubes that can produce a lot of excellent properties of the composite material. Such as carbon nanotubes reinforced plastic material excellent mechanical properties, electrical conductivity, corrosion resistance, shielding radio waves. Make use of cement matrix carbon nanotube composites has good impact resistance, anti-static, anti-wear, high stability, easy to impact on the environment. Carbon nanotubes and metal combine to form a metal matrix composite. Such materials have high strength, high modulus, high temperature, thermal expansion coefficient and strong thermal resistance performance.

 

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What will replace ITO? Metal mesh? Or silver nanowires?

What is ITO?
Indium Tim Oxide(ITO), is a thin-film material, usually used in LCD,PDP,EL/OLED, Touch Panel, Solar Cells and transparency electrode of other electronic instruments.

ITO is now widely used in electronic products, but the future of electronics, such as mobile terminals, wearable devices, smart appliances, etc. Touch panel is hoped to become the large-size, cost-reduction and flexible. This is bound to promote the new materials to replace traditional ITO.
Traditional ITO thin film can’t used in flexible application, and its inherent problems—-conductivity and light transmittance are difficult to overcome. Thus, numerous manufacturers begin to find the substitutes for ITO, such as silver nanowires, metal mesh, carbon nanotubes(CNTs) and graphene.
From technology and marketization level, metal mesh and silver nanowires will be the two major roles in new-developing touch technology.

ITO alternatives – silver nanowires
What is the silver nanowires?
Silver nanowires (SNW, silvernano wire) technology, the silver nanowires ink material is applied on plastic or glass substrate, and then using the laser lithography technology to portray into a transparent conductive film with nanoscale silver line conductive network pattern.
The Advantages and Disadvantages of Silver Nanowires Advantages:
1.the production process is simple and good rate.
2.since the line width is small, the conductive thin film made of silver nanowires technique can achieve higher light transmittance than the one made of a metal grid technology.
3.compared to the metal mesh film, silver nanowires films own a smaller radius of curvature and the resistance change rate is small while bending, the application on devices with surface display, such as smart watches, bracelets, etc, has more advantages.
4.besides excellent electrical conductivity than silver, because of the nanoscale size effect, silver nanowires also have excellent transparency and resistance to flex.
5.large aspect ratio of silver nanowires effect makes its applications in conductive plastic, thermal plastic and other fields also have outstanding advantages.

Disadvantages:
With the severe diffuse reflection light irradiation in outdoor scenes, the screen reflective strongly, you can not see the screen clearly.

Silver nanowires Status
1. although silver nanowires has slightly high raw material costs, its preparation is simple, thus the overall cost is not high. And diffuse phenomenon can use some techniques to reduce;
2. the silver nanowires coated with a high refractive index material film;
3. blackening silver nanowires surface;
4. Reduce the reflective intensity;
5. roughened silver nanowires.

Interesting Copper nanoparticles

Copper nanoparticle synthesis has been gaining attention due to its availability. However, factors such as agglomeration and rapid oxidation have made it a difficult research area. Pure copper nanoparticles were prepared in the presence of a chitosan stabilizer through chemical means. The purity of the nanoparticles was authenticated using different characterization techniques, including ultraviolet visible spectroscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and field emission scanning electron microscopy. The antibacterial as well as antifungal activity of the nanoparticles were investigated using several microorganisms of interest, including methicillin-resistant Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella choleraesuis, and Candida albicans. The effect of a chitosan medium on growth of the microorganism was studied, and this was found to influence growth rate. The size of the copper nanoparticles obtained was in the range of 2–350 nm, depending on the concentration of the chitosan stabilizer.
Copper nanoparticles are very interesting, not only because they show unique nanoscale phenomena like plasmonic absorption and high surface to volume ratio, but also due to useful properties like antibacterial and fungicidal activity. Copper nanoparticles and metal oxide nanoparticles of copper have widespread commercial presence, especially as fungicides. Copper fungicides are extremely effective against certain species of fungi that are common agricultural pathogens. Copper nanoparticles show good to great antimicrobial property against many pathogenic microbes and also used as a commercial antimicrobial agent. Liquid copper dispersions are used as an antimicrobial spray or to prepare antimicrobial surfaces. Other copper nanoparticle applications include conductive ink, chemical sensors, bio sensors etc. Some of these applications may be difficult for you to reproduce at home.
In acidic conditions, copper metal (Cu) in the anode (copper rod attached to the positive wire of the power supply) oxidizes (loses electrons) to form copper ions (Cu+2). These copper ions are released to the solution and will slowly travel towards the cathode (copper rod attached to the negative wire of the power supply). At the cathode, these copper ions will gain electrons and reduces back to copper metal, leaving a metal deposit on the cathode side. This is the main concept behind, electrodeposition.
However, our system is bit different. We have ascorbic acid; a reducing agent (chemical that can donate electrons to induce reduction) in our solution. Also we heat up the solution to spice things up. Now, for the copper ions that are traveling across the solutions, the journey would not be as easy. This is because, copper ions present the ideal opportunity for ascorbic acid molecules to give off their electrons and reduce the copper ions to copper metal. Therefore, in our system copper particles will be formed well before copper ions reach to the cathode.
Ascorbic acid, will not only function as a reducing agent but also as a capping agent. This means that when small copper particles are formed, ascorbic acid molecules will cap or surround the particle making it difficult for similar copper particles to come near to each other. This prevents the uncontrolled growth of the particles to micron sized dimensions.

Related reading: Copper Oxide Nanoparticles Nickel Oxide Nanoparticles

Silver or Silver Nanoparticles

Gold nanoparticles have good stability, small size effect, surface effect, an optical effect and unique biological affinity, in many areas show a potential application, aroused great interest in science and technology workers, scientists have synthesized a silver (Ag) nanocluster that is virtually identical to a gold (Au) nanocluster. On the outside, the silver nanocluster has a golden yellow color, and on the inside, its chemical structure and properties also closely mimic those of its gold counterpart. The work shows that it may be possible to create silver nanoparticles that look and behave like gold despite underlying differences between the two elements, and could lead to creating similar analogues between other pairs of elements.

The researchers, led by Osman Bakr, Associate Professor of Materials Science and Engineering at King Abdullah University of Science and Technology (KAUST) in Saudi Arabia, have published the paper in a recent issue of the Journal of the American Chemical Society.

“In some aspects, this is very similar to alchemy, but we call it ‘nano-alchemy,'” Bakr told Phys.org. “When we first encountered the optical spectrum of the silver nanocluster, we thought that we may have inadvertently switched the chemical reagents for silver with gold, and ended up with gold nanoparticles instead. But repeated synthesis and measurements proved that the clusters were indeed silver and yet show properties akin to gold. It was really surprising to us as scientists to find not only similarities in the color and optical properties, but also the X-ray structure.”

Like all chemical elements, silver and gold are defined by their number of protons: silver has 47, and gold has 79. The work here doesn’t change the number of protons in an atom of silver; otherwise it would no longer be considered silver. Instead, the researchers synthesized a nanocluster of 25 silver atoms, along with 18 other molecules called “ligands” that surround the silver atoms. The entire negatively charged, silver-based complex ion has the chemical formula [Ag25(SPhMe2)18]-.

Although a few other silver nanoparticle have been synthesized in recent years, this is the first silver nanocluster that has a matching analogue in gold: [Au25(SPhMe2)18]- has previously been reported. Besides both nanoclusters having 25 metal atoms and 18 ligands, they also both have all of their atoms and electrons arranged in almost exactly the same way.

In their study, the researchers performed tests demonstrating that the silver and gold nanoclusters have very similar optical properties. Typically, silver nanoclusters are brown or red in color, but this one looks just like gold because it emits light at almost the same wavelength (around 675 nm) as gold. The golden color can be explained by the fact that both nanoclusters have virtually identical crystal structures.

Related reading: Silver Nanoparticles Antimicrobial antibacterial coating nano silver

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