Despite the rise of graphene and other two-dimensional (2-D) materials, semiconducting single-walled carbon nanotubes are still regarded as strong candidates for the next generation of high-performance, ultra-scaled and thin-film transistors as well as for opto-electronic devices. In new work, a European team of researchers demonstrates simultaneous confinement of electrons and holes between artificial defects separated by less than 10 nm in semiconducting carbon nanotubes.
The detection of carbon monoxide (CO) in the air is a vital issue, as CO is a highly toxic gas and an environmental pollutant. Carbon monoxide is poisonous because it blocks the binding site for oxygen in hemoglobin. It is exactly this principle - a porphyrin ring with a central iron or cobalt atom that the poisonous gas attaches to - that can be used to implement sensors to warn against carbon monoxide. While carbon monoxide sensors have been extensively researched and commercialized, none make use of a molecule that can be voltage-activated using a newly reported method.
Metal-organic frameworks (MOFs) are well-ordered, lattice-like crystals. The nodes of the lattices are metals, which are connected by organic molecules. Their size-controllable nanopores, special structure and large surface area make MOFs very attractive materials for next-generation, highly sensitive gas sensors. In new work, researchers demonstrate a process that can be used for developing low-cost and highly sensitive gas sensors. By increasing the sensitivity, the amount of gas sensitive material and device size can be reduced which in turn would reduce the overall cost of the device and energy consumption.
Researchers have focused on nanocellulose as a novel biomaterial with industrial and scientific applications, which range from the creation of new kinds of commercially useful materials and uses in medical technology all the way to the food and pharmaceutical industries. Engineers now have developed a new use for nanofibrillated cellulose by combining it with carbon nanotubes to form strong, conductive microfibers through a 3D-printing process. The team's 3D-printed wood nanocellulose-carbon nanotube microfibers combine high electrical conductivity and mechanical strength, which can be potentially used in wearable electronics with high performance and low cost.
Turning atmospheric carbon dioxide (CO2) into valuable products seems like a great idea to help remove this greenhouse gas to mitigate climate change. Using a process of molten carbonate electrolytic transformation of CO2 to carbon nanotubes, researchers have now demonstrated 'carbon nanotube wool'. These are the first carbon nanotubes that can be directly woven into a cloth as they are of macroscopic length (over 1mm) and are cheap to produce. The sole reactant to produce the carbon nanotube wools is carbon dioxide. This transforms CO2 from a pollutant into a useful, valuable resource.
New work demonstrates that one of the most important security primitives, i.e. a true random number generator (TRNG), can be realized within the rigorous constraints required for future Internet-of-Things electronics. The solution-processability of semiconducting single-walled carbon nanotubes allows to meet these strict constraints by simultaneously enabling small-scale, low cost fabrication of low-power, ultra-thin, printable, and mechanically flexible security devices. This presents a significant milestone in enabling higher level cryptographic solutions using scalable solution processing.
In spite of the numerous research efforts regarding the development of miniaturized, low-cost, and highly sensitive sensors based on different organic and semiconducting materials, carbon nanotubes still remain the most promising ones. An international team of researchers has now developed a simple way for fabrication and operation of carbon nanotube-based chemical sensors. The sensor consists of carboxylated single-walled carbon nanotubes, which were spin-coated over the polymer substrate between sputtered metal electrodes.
In two new studies, researchers show that cement plants can have their carbon dioxide exhaust eliminated while co-producing carbon nanotubes. They demonstrate that with their C2CNT (carbon dioxide into carbon nanotubes) process, a wide portfolio of tailored carbon nanotubes, such as those with special shapes or conductivity can be made. C2CNT is a straightforward process that transforms CO2 to carbon nanotubes by molten electrolysis with inexpensive (nickel and steel) electrodes and low voltage. This synthesis consumes only CO2 and electricity, and is constrained only by the cost of electricity.