Phys.org October 28, 2020 While surface charge state of co-catalysts plays a critical role for boosting photocatalysis, the study on surface charge regulation via their precise structure control, remains rare. Researchers in China have fabricated an MOF-stabilized bimetallic Pd-Pt nanoparticles which feature adjustable Pt coordination environment and the controlled structure from core-shell to single-atom alloy (SAA). They found that Pt surface charge regulation can be alternatively achieved by changing its coordination environment and the structure of Pd-Pt co-catalyst, where the charge between Pd and Pt is redistributed. The optimized Pd-Pt composite exhibits an exceptionally high photocatalytic hydrogen production activity, far […]
Tag Archives: Advanced material
Chemists develop a new type of one-molecule thick water-repellent film
Nanowerk September 9, 2020 An international team of researchers (Russia, Belarus) developed 0.8-1.5 nm thick calixarene-based films that can work as water-repellent coatings. Calixarenes are large bowl-shaped organic molecules that consist of several rings. The outer ring of the bowl is hydrophilic, and the innermost ring is hydrophobic. Their durability can be increased with UV radiation. The films can be used to create protective hydrophobic or anti-corrosion coatings for organic electronics or to develop molecular filters…read more. TECHNICAL ARTICLE
A new iron based super elastic alloy capable of withstanding extreme temperatures
EurekAlert August 20, 2020 Researchers in Japan have discovered novel iron-based super elastic alloy (SEA) made of Fe-Mn-Al-Cr-Ni whose controllable temperature dependence goes from positive to negative, it is capable of withstanding extreme temperatures -both high and low. Increasing the amount of Chromium allowed the researchers to change the temperature dependence from a positive to a negative. Balancing the Chromium content resulted in zero temperature dependence with the critical stress remaining almost constant at various temperatures. The discovery possesses wide-spread application for outer-space exploration given the large temperature fluctuations that occur. It can potentially be used in tension braces in […]
Scientists use photons as threads to weave novel forms of matter
EurekAlert August 17, 2020 An international team of researchers (UK, France, Italy) has spectroscopically observed bound electrons and holes, leading to the creation of an intraband bound exciton. The discrete resonance appears below the ionization threshold only when the coupling between light and matter is increased above a critical value. The result demonstrates that two charged particles can be bound by the exchange of transverse photons. Light–matter coupling can thus be used as a tool in quantum material engineering, tuning electronic properties of semiconductor heterostructures beyond those permitted by mere crystal structures, with direct applications to mid-infrared optoelectronics…read more. TECHNICAL […]
UBCO researchers create liquid-repelling substance that works on all surfaces
EurekAlert July 15, 2020 Omniphobic–all-liquid repellent–films can repel a broad range of liquids, but the applicability of these coatings has always been limited to silicon wafers or smooth glass. Researchers in Canada have developed a facile procedure to generate an omniphobic coating on any surface, including metals, paper, ceramics, etc. The process involves depositing an ultra smooth, silicon wafer-like silica layer and then treating this layer with a highly reactive chlorosilane, which grafts polydimethylsiloxane chains onto the surface. Negligible contact angle hysteresis (≤1°) for various liquids, including ultralow surface tension oils, alcohols, and fluoro-solvents, was achieved on many different substrates […]
The lightest shielding material in the world
EurekAlert July 2, 2020 An international team of researchers (Switzerland, Singapore) used nanofibers of cellulose as the basis for making an aerogel which is a light, highly porous material. Cellulose fibres obtained from wood enable a wide range of chemical modifications. The composite of cellulose nanofibers and silver nanowires created ultra-light fine structures which provide excellent shielding against electromagnetic radiation. The material has a density of 1.7 milligrams per cubic centimeter, achieves more than 40 dB shielding in the frequency range of high-resolution radar radiation (8 to 12 GHz) – in other words: virtually all radiation in this frequency range […]
Finding the ‘magic angle’ to create a new superconductor
Science Daily October 2, 2019 Earlier this year, scientists at MIT reported that graphene could become a superconductor if one piece of graphene were laid on top of another piece and the layers twisted to a specific angle , they called “the magic angle” of between 1 degree and 1.2 degrees. Now an international team of researchers (USA – Ohio State University, TT Dallas, Japan) found that graphene layers still superconducted at a smaller angle, around 0.9 degrees. It is a small distinction, but the findings provide a wealth of new information to help decipher the strongly correlated phenomena observed […]
Engineering for high-speed devices
Science Daily March 29, 2019 A team of researchers in the US (University of Delaware, industry, Columbia University) combined silicon with graphene which can transmit radiofrequency waves in less than a picosecond at a sub-terahertz bandwidth. Graphene has better carrier mobility and direct bandgap and allows for faster electron transmission and better electrical and optical properties. By combining silicon with graphene, scientists may be able to continue to utilize technologies that are already used with silicon devices. The research could add up to cheaper and faster wireless devices in the future. It could make the network stronger, better and cheaper…read […]
World’s first passive anti-frosting surface fights ice with ice
Science Daily September 17, 2018 A team of researchers in the US (Virginia Tec, Oak Ridge National Laboratory) created their anti-frosting surface on untreated aluminum by patterning ice stripes onto a microscopic array of elevated grooves. The microscopic grooves act as sacrificial areas, where stripes of intentional ice form and create low pressure zones. These low-pressure areas pull nearby moisture from the air onto the nearest ice stripe, keeping the overlapping intermediate areas free of frost, even in humid, sub-freezing conditions. These sacrificial ice stripes make up only 10 percent of the material’s surface area, leaving the remaining 90 percent […]
Nanotube ‘rebar’ makes graphene twice as tough
Science Daily August 4, 2018 In 2014 Rice University researchers developed Rebar graphene that consists of CNTs embedded in graphene. An international team of researchers (USA – Rice University, University of Maine, Brown University, China) implemented a “dry” transfer technique to test the freely suspended rebar graphene under uniaxial tension mode. Combined experiments and molecular dynamics simulations confirmed that the embedded CNTs divert and bridge the propagating crack and provide a toughening mechanism for the material. This is a promising extrinsic toughening strategy for 2D materials and provides mechanistic insights into the fracture process of graphene hybrid material. The experiments […]