Nanowerk May 31, 2021 For successful implementation of photoelectrocatalytic synthesis of fuels and value-added chemicals hybrid photoelectrodes with low energy consumption and high photocurrent densities are essential. Researchers in Japan have developed a laser-driven technology to print sensitizers with desired morphologies and layer thickness onto different substrates, such as glass, carbon, or carbon nitride (CN). The process uses a thin polymer reactor impregnated with transition metal salts, confining the growth of TMO nanostructures on the interface in milliseconds, while their morphology can be tuned by the laser. Multiple nano-p-n junctions at the interface increase the electron/hole lifetime by efficient charge […]
Category Archives: Advanced materials
One material, two functionalities
Nanowerk May 25, 2021 Flexible metamaterials often harness zero-energy deformation modes. To date they have a single property, such as a single shape change, or are pluripotent. An international team of researchers (the Netherlands, Switzerland) has introduced a class of oligomodal metamaterials that encode a few distinct properties that can be selectively controlled under uniaxial compression. They demonstrated this concept by introducing a combinatorial design space containing various families of metamaterials. They included monomodal (with a single zero-energy deformation mode); oligomodal (with a constant number of zero-energy deformation modes); and plurimodal (with many zero-energy deformation modes), whose number increases with system […]
Harvesting light like nature does
Nanowerk May 15, 2021 Inspired by the formation of hierarchically structured natural biominerals (e.g., bone and tooth), various sequence-defined polymers have been synthesized and exploited for design and synthesis of functional hybrid materials. A team of researchers in the US (Pacific Northwest National Laboratory, Washington State University) created an altered protein-like structure, called a peptoid, and attached a precise silicate-based cage-like structure to one end of it. They found that, under the right conditions, they could induce these molecules to self-assemble into perfectly shaped crystals of 2D nanosheets. It has the programmability of a protein-like synthetic molecule with the complexity […]
Nanoscale defects could boost energy storage materials
Phys.org May 11, 2021 A team of researchers in the US (Cornell University, Virginia Tech, Argonne National Laboratory) synthesized a garnet crystal structure, lithium lanthanum zirconium oxide (LLZO), with various concentrations adding aluminum as a dopant. Through Bragg Coherent Diffractive Imaging they found the material’s morphology and atomic displacements. The researchers now plan to conduct a study that measures how the defects impact the performance of solid-state electrolytes in an actual battery. The study opens the possibility to design defects to make better energy storage materials…read more. TECHNICAL ARTICLE
Nature provides inspiration for breakthrough in self-regulating materials
Phys.org April 27, 2021 To make a series of oscillators to work in unison with each other, a team of researchers (UMass Amherst, Boston University, Harvard University, University of Colorado) has developed a versatile platform of light-driven active particles with interaction geometries that can be reconfigured on demand, enabling the construction of oscillator and spinner networks. The platform relies on the Marangoni effect, which is a phenomenon that describes the movement of solids along the interface between two fluids driven by changes in surface tension. They used hydrogel nanocomposite disks made up of polymer gels and nanoparticles of gold, which […]
New two-dimensional material
Science Daily April 27, 2021 An international team of researchers (USA – Carnegie Institution for Science, Howard University, University of Chicago, Argonne National Laboratory, Germany, France, Russia, Sweden, the Netherlands, China) used the laser-heated diamond anvil cell technique with pressures of up to 100 gigapascals, to synthesize a Dirac material beryllonitrene (BeN4). These are beryllium polynitrides, some of which conform to the monoclinic, others to the triclinic crystal system. The triclinic beryllium polynitrides exhibit an unusual characteristic when the pressure drops. They take on a crystal structure made up of layers. Each layer contains zigzag nitrogen chains connected by beryllium […]
Electrifying cement with nanocarbon black
Nanowerk April 21, 2021 Researchers at MIT performed an experimental-theoretical investigation of the electrical conductivity and resistive heating of highly heterogeneous nanocarbon–cement-based composites (pastes and mortars). Even a small voltage — as low as 5 volts — could increase the surface temperatures of their samples (approximately 5 cm3 in size) up to 41 degrees Celsius (around 100 degrees Fahrenheit). They found that electrical conductivity is determined by the electric tortuosity of a “volumetric wiring” permeating a highly heterogeneous matrix from percolation to saturation. They showed that the electric energy dissipation at the origin of the Joule heating originates from spatial […]
Anti-reflective films: What high-tech can learn from plants
EurekAlert April 13, 2021 Rose petals have a matt and at the same time rich color. The outer tissue of its petals, the epidermis, consists of densely packed microstructures, additionally ribbed by nanostructures. With these structures, the rose manages to couple all incident light into the cells – only the colored light escapes again. Researchers in Germany combined micro- and nanostructure to develop an anti-reflective film that replicates the epidermis of rose petals. The film increases the yield of solar modules by up to ten percent. Posters, display panels, traffic signs, furniture, packaging, facades, and many other applications also benefit […]
Transforming circles into squares
Science Daily April 14, 2021 The fundamental topology of cellular structures can profoundly affect their acoustic, electrical, chemical, mechanical, and optical properties, as well as heat, fluid, and particle transport. In the previous techniques the resulting structures generally preserve the defining connectivity features of the initial topology. Researchers at Harvard University have developed a two-tiered dynamic strategy that achieves systematic reversible transformations of the fundamental topology of cellular microstructures, which can be applied to a wide range of materials and geometries. The approach requires exposing the structure to a selected liquid that can first infiltrate and plasticize the material at […]
Big breakthrough for ‘massless’ energy storage
Science Daily March 22, 2021 Stiff and strong batteries that use solid‐state electrolytes and resilient electrodes and separators are generally lacking. Researchers in Sweden have demonstrated a structural battery composite with unprecedented multifunctional performance featuring an energy density of 24 Wh kg−1 and an elastic modulus of 25 GPa and tensile strength exceeding 300 MPa. The structural battery is made from multifunctional constituents, where reinforcing carbon fibers (CFs) act as electrode and current collector. A structural electrolyte is used for load transfer and ion transport and a glass fiber fabric separates the CF electrode from an aluminum foil‐supported lithium–iron–phosphate positive electrode. The battery performs […]