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Carbon, oxygen and hydrogen. These are the three elements that you would get if you separated the carbon dioxide and water molecules. The same atoms are the building blocks of the chemical compounds we use as fuel, such as ethanol and methane. If it was possible to convert carbon dioxide and water into a renewable fuel, this could be an alternative to using fossil fuels and help reduce our carbon dioxide emissions in the future. 39; atmosphere.
Jianwu Sun, associate professor at Linköping University, is currently studying a way to do this.
The first step is that researchers must develop the material that they intend to use. Researchers at Linköping University (LiU) have previously developed a silicon carbide production method, one of the best in the world, made of silicon and carbon. The cubic shape has the ability to capture solar energy and create charge carriers.
Subject to unique characteristics
But this is not enough. The graphic, one of the thinnest materials ever produced, now plays the leading role in the project. The material consists of a single layer of carbon atoms that bind to each other in a hexagonal pattern in chicken fillet. The graph has a great ability to conduct electrical current, a property that can be used to transform solar energy. It also has several unique features and the world is currently the subject of much research on the possible applications of the graph.
In recent years, researchers have sought to develop the process of graph growth on a surface to control the properties of the graph. An article recently published in Carbon magazine describes one of the latest advances.
– It is relatively easy to develop a layered graph on cubic silicon carbide. However, if you want to enlarge the chart in even-numbered layers over a larger area, the challenge is greater. Now we show that it is possible to control in a controlled manner up to four layers of even graphs, says Jianwu Sun of the Department of Physics, Chemistry and Biology (IFM).
Create even more stock
One of the difficulties with the multilayered tomb is that the surface becomes uneven because of the fact that there are different layers in different places. The edge of a warehouse ends with a small staircase at the nanoscale. For researchers who want large and regular surfaces, these steps can be an obstacle. Particularly disturbing, when the stairs go up, the staircase joins the same place, in the manner of a filthy staircase, where several steps were squeezed together at a level too high. Now, scientists have found a way to get rid of the phenomenon of step by step by developing the graph under a carefully adjusted temperature and duration. In addition, LiU researchers have shown that this approach makes it possible to control the number of layers composing the graph. This is the first step of the research project to manufacture fuel from water and carbon dioxide.
In a closely related scientific article, published in the journal Nano Letters, researchers studied the electronic properties of a multilayered tomb planted on cubic silicon carbide.
Can be used as a superconductor
– We have found that the multilayer graft has very promising electrical properties, which allow the material to be used as a superconductor with zero resistance. This peculiarity only appears when the layers of graphs are organized in a particular way with respect to each other ", explains Jianwu Sun.
In previous research, theoretical calculations predicted that these properties might appear when graph layers are organized in a particular way. The present study is the first to demonstrate experimentally that this is indeed the case. Ultraconductive materials are used in superconducting magnets, which are very resistant and used in magnetic cameras for medical examinations and particle accelerators for research purposes. Many hope that superconductors will be able to be used on power lines without energy losses or on high speed trains floating on magnetic fields, among other things. Current use is limited by the fact that the superconductors present do not operate at room temperature, but only at extremely low temperatures.
note:
The studies were conducted with researchers at the Lund MAX IV Laboratory and were funded with support from the Swedish Research Council, FORMAS, STINT, the ÅForsk Foundation and the Olle Engkvist Byggmästare Foundation.
Contact:
Jianwu Sun, Associate Professor, Department of Physics, Chemistry and Biology (IFM), Linköping University, [email protected], 013-28 27 03
Articles:
Deletion of steps in the growth of large-area monolayer and multilayer graphene on off-axis 3C-SiC, Yuchen Shi, Alexei A. Zakharov, Ivan G. Ivanov, Reza Yazdi G., Valdas Jokubavicius, Mikael Syväjärvi, Rositsa Yakimova and Jianwu Sun, (2018). Carbon, 140, 533-542
Flat-band electronic structure and inference in rhombohedral four-layer graphene, Weimin Wang, Shi Yuchen, Alexei A. Zakharov, Mikael Syväjärvi, Rositsa Yakimova, Roger Uhrberg IG and Jianwu Sun, (2018), Nano Lett. 18 (9) 5862-5866
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