Phys.org October 11, 2023 Using the Pt metal as the shell material of the catalyst in polymer electrolyte membrane fuel cells not only increases the surface area but also creates an interfacial interaction between the core metal and platinum, which results in enhanced catalytic activity. Researchers in Canada surface doped Pd@Pt nanoparticles with cobalt to further boost their durability and activity. Characterizing the synthesized catalyst with X-ray absorption fine structure at the Pt L3-edge and cobalt K-edges, together with performance tests, revealed information about the effect of the dopants on the catalytic activity of catalysts. The results of the local […]
Tag Archives: S&T Canada
Decoding how molecules ‘talk’ to each other to develop new nanotechnologies
Nanowerk August 14, 2023 Many scientists believe that the key to designing and programming more complex and useful artificial nanosystems relies on our ability to understand and better employ molecular languages developed by living organisms, namely allostery (molecule binds and modifies the structure of another molecule) and multivalency, (facilitates (or not) the binding of a third molecule by simply increasing its binding interface). As a proof-of-concept researchers in Canada engineered a highly programmable DNA-based switch that could be triggered by either a multivalent or an allosteric DNA activator. By precisely designing the binding interface of the multivalent activator, they showed […]
Capturing non-transparent ultrafast scenes
Phys.org May 26, 2023 Real-time imaging modalities with ultrahigh temporal resolutions are required for capturing ultrashort events on picosecond timescales for unveiling many fundamental mechanisms in physics, chemistry, and biology. Current single-shot ultrafast imaging schemes operate only at conventional optical wavelengths, being suitable solely within an optically transparent framework. Researchers in Canada leveraged the unique penetration capability of terahertz radiation to demonstrate a single-shot ultrafast terahertz photography system that could capture multiple frames of a complex ultrafast scene in non-transparent media with sub-picosecond temporal resolution. By multiplexing an optical probe beam in both the time and spatial-frequency domains, they encoded […]
Researchers advance insights into cause of ripples on icicles
Science Daily December 5, 2022 Icicles that have grown from slightly impure water develop ripples around their circumference. The ripples have a near-universal wavelength and are thought to be the result of a morphological instability. Researchers in Canada used laboratory-grown icicles and various species of impurities, including fluorescent dye, to show that a certain fraction of the impurities remains trapped inside the icicle, forming inclusions within the ice. The inclusions were organized into chevron patterns aligned with the peaks of the ripples. Within the chevrons, there was a substructure of crescent-shaped structures. They also examined the crystal grain structure of […]
Glass-like shells of diatoms help turn light into energy in dim conditions
Nanowerk November 22, 2022 Using a toolkit consisting of numerical models and four microscopy techniques, researchers in Canada evaluated the optical response of frustules belonging to the species Nitzschia filiformis. Localized regions of the frustule exhibited functionalities including diffraction, lensing, waveguiding, circulation, filtering, resonances, and dispersion control. They showed that these functionalities are complementary to each other in contributing to the solar energy harvesting mechanisms of capture, redistribution, and retention. In this context, frustule performance was enhanced by perturbations to its sub-wavelength structure. According to the researchers their finding provides quantitative support to the hypothesis that the frustule enhances photosynthesis […]
Penguin feathers may be secret to effective anti-icing technology
Phys.org October 24, 2022 The body feathers of perpetually ice-free penguins are very good natural examples of anti-icing surfaces, which use two different mitigation strategies for the two disparate problems – water adhesion and ice adhesion. Researchers in Canada constructed the form of the feather’s wire-like structure and decorated it with superimposed nanogrooves by laser micromachining fine woven wire cloths. Post-processing techniques also allowed them to isolate the role of surface chemistry by creating both hydrophilic and hydrophobic versions of the synthetic anti-icing surfaces. Their results showed that water-shedding and ice-shedding characteristics are indeed derived from different physical functions of […]
Producing hydrogen from seawater
Phys.org September 13, 2022 The direct electrolysis of seawater is greatly inhibited by the oxidation of Cl– to free chlorine, an undesirable, corrosive byproduct. To suppress the interference of Cl– and any other ion, researchers in Canada developed a freestanding, electrically conducting, 3D macroporous reduced graphene oxide (rGO) scaffold with cobalt oxide particles selectively deposited on the internal walls of its closed pores. The pore walls act as membranes composed of stacked rGO flakes; the nanochannels between rGO layers are permeable to water and gases while preventing the diffusion of dissolved ions such as Cl–. Due to this, the catalytic […]
Researchers find the missing photonic link to enable an all-silicon quantum internet
Phys.org July 13, 2022 The global quantum internet will require long-lived, telecommunications-band photon–matter interfaces manufactured at scale. Preliminary quantum networks based on photon–matter interfaces that meet a subset of these demands are encouraging efforts to identify new high-performance alternatives. Silicon is an ideal host for commercial-scale solid-state quantum technologies. It is already an advanced platform within the global integrated photonics and microelectronics industries, as well as host to record-setting long-lived spin qubits. Despite the overwhelming potential of the silicon quantum platform, the optical detection of individually addressable photon–spin interfaces in silicon have remained elusive. In their work researchers in Canada […]
Review suggests current global efforts are insufficient to limit warming to 1.5°C
Phys.org June 24, 2022 According to researchers in Canada human activities have caused global temperatures to increase by 1.25°C, and the current emissions trajectory suggests that we will exceed 1.5°C in less than 10 years. Though the growth rate of global carbon dioxide emissions has slowed, and many countries have strengthened their emissions targets, current midcentury net zero goals are insufficient to limit global warming to 1.5°C above preindustrial temperatures. The primary barriers to the achievement of a 1.5°C-compatible pathway are not geophysical but rather reflect inertia in our political and technological systems. Both political and corporate leadership are needed […]
Riding a laser to Mars
Phys.org February 8, 2022 Responding a NASA solicitation to send a sagecraft to Mars using laser, researchers in Canada are exploring laser-thermal propulsion. An Earth-based laser array of 10 m diameter and power 100 MW would be able to deliver laser power to spacecraft in cislunar space, where the incident laser is focused into a hydrogen heating chamber via an inflatable reflector. The hydrogen propellant is then exhausted through a nozzle to realize specific impulses of 3000 s. The architecture is shown to be immediately reusable via a burn-back maneuver to return the propulsion unit while still within range of […]