Nanowerk November 9, 2022 While technological developments of 2D MOFs typically take advantage of substrates for growth, support, and electrical contacts, investigations often ignore substrates and their dramatic influence on electronic properties. Researchers in Australia have shown how substrates alter the correlated magnetic phases in Kagome MOFs using systematic density functional theory and mean-field Hubbard calculations. They demonstrated that MOF-substrate coupling, MOF-substrate charge transfer, strain, and external electric fields are key variables, activating and deactivating magnetic phases in these materials. They used the Kagome-arranged 9,10-dicyanoanthracene molecules coordinated with copper atoms as an example. According to the researchers their findings can […]
New technology creates carbon neutral chemicals out of thin air
Nanowerk November 9, 2022 An international team of researchers (UK, Spain) has demonstrated the feasibility of a Dual Function Material’s (DFM) ability to passively capture CO2 directly from the air opening the possibilities of chemical production from dilute sources of CO2, through a combination of CO2 adsorption and subsequent chemical transformation. Combinations of Ni Ru bimetallic catalyst with Na2O, K2O or CaO adsorbent were supported on CeO2–Al2O3 to develop flexible DFMs. They were shown to reversibly adsorb CO2 between the 350 and 650 °C temperature range and were easily regenerated by an inert gas purge stream. Captured CO2 could be […]
Novel copper gas penetration electrode can efficiently reduce CO2 to multicarbon products
Phys.org November 8, 2022 Although considerable progress has been made in CO2 electroreduction, sustained production of multicarbon compounds at high current density remains a challenge. Researchers in China reported a hierarchical micro/nanostructured Cu(100)-rich copper hollow fiber as a gas penetration electrode (GPE) that reduces CO2 to C2+ product with a faradaic efficiency of 62.8% and a current density of 2.3 A cm-2 in 0.5 M KHCO3 solution at −1.94 V (vs. RHE). Electrochemical results demonstrate that optimized mass transfer and enhanced three-phase interface reaction synergistically promote CO2 activation and reduction kinetics. Theoretical calculations suggested that the Cu(100) facet of Cu […]
Seeing clearly into a new realm—researchers prototype a new generation of quantum microscopy
Phys.org November 7, 2022 Quantum microscopes for probing material properties and physical processes have relied on quantum defects hosted in rigid, three-dimensional (3D) crystals such as diamond, limiting their ability to closely interface with the sample. An international team of researchers (Australia, China) built a prototype quantum microscope embedding point defects within a thin layer of the van der Waals material hexagonal boron nitride. To show the multi-modal capabilities of this platform, they assembled two different heterostructures of a van der Waals material in combination with a quantum-active boron nitride flake and demonstrated time-resolved, simultaneous temperature and magnetic imaging near […]
Seeing concentrations of toxins with the naked eye
Phys.org November 3, 2022 Current detection methods can only respond to changes in a droplet’s bulk wetting properties, leading to poor detection limits. A team of researchers in the US (Harvard University, Ohio State University) has developed a design principle that overcomes this fundamental limitation by locally concentrating analytes within a droplet’s contact line to modulate the local surface roughness, which further affects droplet mobility. They designed surfaces enabled the ultrasensitive, naked-eye detection of amphiphiles through changes in the droplets’ sliding angles, even when the concentration is four to five orders of magnitude below their critical micelle concentration. They developed […]
Surface melting of glass
Science Daily November 4, 2022 Microscopic properties of glasses largely differ from that of the bulk material. Researchers in Germany experimentally investigated the surface of a two-dimensional glass as a function of the effective temperature. They used colloidal suspension of micron-sized particles interacting via tunable critical Casimir forces to a free surface. They observed surface melting of the glass. However, underneath they found a region with bulk density but much faster particle dynamics. which resulted from connected clusters of highly mobile particles which are formed near the surface and deeply percolate into the underlying material. Because its thickness can reach […]
Team creates crystals that generate electricity from heat
Phys.org November 6, 2022 An international team of researchers (France, Japan, Germany) synthesized a series of self-doped compounds Cu2+xMn1−xGeS4 through Cu for Mn substitution. Using a combination of powder X-ray diffraction, high resolution transmission electron microscopy and precession-assisted electron diffraction tomography, they showed that the materials were composed of interconnected enargite- and stannite-type structures, via the formation of nanodomains with a high density of coherent interfaces. By combining experiments with ab initio electron and phonon calculations, they discussed the structure–thermoelectric properties relationships and clarified the interesting crystal chemistry in this system. They demonstrated that excess Cu+ substituted for Mn2+ dopes […]
Ultrathin solar cells promise improved satellite performance
Nanowerk November 8, 2022 Ultra-thin solar cells’ radiation tolerance may allow them to be used in harsh radiation environments, where thicker cells would degrade rapidly. Researchers in the UK irradiated devices with an 80 nm GaAs absorber layer with 3 MeV protons. They mapped the introduction of radiation-induced defects with increasing proton fluence and characterized a decrease in carrier lifetime after irradiation fluence. Despite the substantial reduction in carrier lifetime, short-circuit current did not degrade up to a proton fluence of 1 × 1015 cm−2, beyond which the short-circuit current collapsed. The exposure correlated with the point at which the carrier lifetime became comparable to […]
Top 10 Science and Technology Inventions for the Week of November 4, 2022
01. The answer is in the sheets: 2D nanosheets as anodes in Li-ion batteries 02. Electrical gating of the charge-density-wave quantum phases opens innovative electronic applications 03. In nanotube science, is boron nitride the new carbon? 04. New Hybrid Virus Discovered as Flu And RSV Fuse Into Single Pathogen 05. Overcoming the optical resolution limit 06. Physicists see light waves moving through a metal 07. Quantum dots form ordered material 08. Researchers design next-generation electrolytes for lithium batteries 09. Revolutionary technique to generate hydrogen more efficiently from water 10. Scientists discover material that can be made like a plastic but […]
The answer is in the sheets: 2D nanosheets as anodes in Li-ion batteries
Phys.org October 31, 2022 2D nanostructures based on transition-metal diborides (TMDs) are theoretically predicted to possess an exceptionally high rate and long cycling stability for Li-ion storage owing to the intrinsic presence of boron honeycomb planes and multivalent transition-metal atoms. An international team of researchers (Japan, India) investigated the Li-ion storage potential of the TMD-based nanostructure–titanium diboride (TiB2)-based hierarchical nanosheets (THNS). They demonstrated that THNS can be utilized as a high-rate anode material for Li-ion battery (LIB) and that a high discharge capacity can be obtained at a current rate of 0.025 A g1– galvanostatic charge/discharge. They demonstrated that the […]