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.
Metal-organic frameworks (MOFs) are well-ordered, lattice-like crystals. The nodes of the lattices are metals, which are connected by organic molecules. The most impressive features of MOFs are their extremely high surface area, high porosity, and tunable pore sizes, which are remarkable advantages over other porous materials (e.g., zeolites and carbons). With their special structure and large surface area, MOFs open up new opportunities for alternative systems for gas and energy storage (e.g. carbon dioxide and hydrogen storage), in catalysis, chemical sensing, as nanoreactors, and in drug delivery, making them hugely interesting for both university research and industry.
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.
The serious threat of particulate matter (PM) air pollution to human health spurs development of advanced filter technologies. Particular efforts have been made in designing air filters with both high filtration efficiency and low airflow resistance by utilizing carbon nanotubes and electrospun polymer and inorganic nanofibers. In new work, scientists explored the performance of electrospun silk nanofiber membranes as air filters, which showed both of lightweight and high efficient features.
Newly developed nanocomposites possess efficient photothermic properties for highly targeted interfacial phase transition reactions that are synergistically favorable for seawater catalysis and desalination. The nanocomposites are seawater and photostable for practical solar conversion of seawater to simultaneously produce clean energy and water. This work defines the forefront of plasmonic photothermic technology, which is vastly untapped and has broad implications in other fields.
Inspired by the multiple water purification mechanisms of water hyacinth, a group of researchers has combined different decontamination techniques - adsorption, photocatalytic degradation, distillation - into a single paper-based composite system for water purification by using solar light as the clean energy input. Compared with water treatment with a single mechanism, the multifunctional composite reported in this work could significantly enhance the clean water generation efficiency and maximize the use of the broad-spectrum solar light in a facile and effective way.
Self-powered nanotechnology based on these nanogenerators aims at powering nanodevices and nanosystems using the energy harvested from the environment in which these systems are suppose to operate. An interesting approach comes from a group of Chinese scientists who propose to scavenge the large amounts of wasted wind energy in cities: they propose hybridized nanogenerator that consists of a solar cell and a triboelectric nanogenerator, which can be utilized to individually or simultaneously scavenge solar and wind energies.
This dossier is concerned with the question to what extent a concept along the lines of the 'green nano design principles' developed by the German NanoCommission can contribute to environmentally friendly developments in the area of nanotechnology. For this purpose, it introduces research projects which have implemented certain aspects of the green nano design principles. Moreover, on the basis of technological and scientific research and development, the question is raised whether or not, and if so, to what extent concepts such as green nano design principles can support the incorporation of environmental aspects into research.