Impact of Pressure on Metavalent Bonding in BiTe influencing Electronic Topological Transitions.

BiTe, a member of the (Bi2)m(Bi2Te3)n homologous series, possesses natural van der Waals-like heterostructure with a Bi2 bilayer sandwiched between the two [Te-Bi-Te-Bi-Te] quintuple layers. BiTe exhibits both the quantum states of weak topological and topological crystalline insulators, making it a dual topological insulator and a suitable candidate for spintronics, quantum computing and thermoelectrics. Herein, we demonstrate that the chemical bonding in BiTe is to be metavalent, which plays a significant role in the pressure dependent change in the topology of the electronic structure Fermi surface.

Decoding the Hume-Rothery Rule in a Bifunctional Tetra-metallic Alloy for Alkaline Water Electrolysis.

The 90-year-old Hume-Rothery rule was adapted to design an outstanding bifunctional tetra-metallic alloy electrocatalyst for water electrolysis. Following the radius mismatch principles, Fe (131 pm) and Ni (124 pm) are selectively incorporated at the Pd (139 pm) site of MoPd nanosheets. Analogously, Cu (132 pm) alloys with only Pd, while Ag (145 pm) alloys with both Pd and Mo (154 pm).

Coupling-Induced Dynamic Off-Centering of Cu Drives High Thermoelectric Performance in TlCuS.

Seeking new and efficient thermoelectric materials requires a detailed comprehension of chemical bonding and structure in solids at microscopic levels, which dictates their intriguing physical and chemical properties. Herein, we investigate the influence of local structural distortion on the thermoelectric properties of TlCuS, a layered metal sulfide featuring edge-shared Cu-S tetrahedra within CuS layers. While powder X-ray diffraction suggests average crystallographic symmetry with no distortion in CuS tetrahedra, the synchrotron X-ray pair distribution function experiment exposes concealed local symmetry breaking, with dynamic off-centering distortions of the CuS tetrahedra.

Computer simulations of entropic cohesion in reversibly crosslinked polymers.

Reversibly crosslinked polymer networks - polymer networks that can undergo bond association and dissociation reactions - rearrange their structures while maintaining their overall integrity, thus resulting in unique properties such as self-healing, reprocessability, shape memory and adaptability. Here, we show that the introduction of crosslinks, whether reversible or permanent, directly impacts the equilibrium polymer density and hence the material's surface tension. For a limiting case where the bonds are the same size as the polymer chain bonds, simulations, Flory hypotheses and thermodynamic calculations show that the crosslinks induce an increased entropic cohesion in the liquid.

Charge noise in low Schottky barrier multilayer tellurium field-effect transistors.

Creating van der Waals (vdW) homojunction devices requires materials with narrow bandgaps and high carrier mobilities for bipolar transport, which are crucial for constructing fundamental building blocks like diodes and transistors in a 2D architecture. Following the recent discovery of elemental 2D tellurium, here, we systematically investigate the electrical transport and flicker noise of hydrothermally grown multilayer tellurium field effect transistors. While the devices exhibit a dominant p-type behavior with high hole mobilities up to ∼242 cm V s at room temperature and almost linear current-voltage characteristics down to 77 K, ambipolar behavior was observed in some cases.

Peptide-based nanomaterials and their diverse applications.

The supramolecular self-assembly of peptides offers a promising avenue for both materials science and biological applications. Peptides have garnered significant attention in molecular self-assembly, forming diverse nanostructures with α-helix, β-sheet, and random coil conformations. These self-assembly processes are primarily driven by the amphiphilic nature of peptides and stabilized by non-covalent interactions, leading to complex nanoarchitectures responsive to environmental stimuli.

The impact of ligand chain length on the HER performance of atomically precise Pt(SR) nanoclusters.

Atomically precise metal cluster-based electrocatalysts have been paid significant attention for an efficient hydrogen evolution reaction (HER). Herein, we have synthesized atomically precise Pt(SR) nanoclusters using 3-mercaptopropionic acid (MPA), 6-mercaptohexanoic acid (MHA), 8-mercaptooctanoic acid (MOA), and 11-mercaptoundecanoic acid (MUA) thiol ligands in aqueous media at room temperature to understand the impact of ligand chain length on the HER performance. The composition of Pt(SR) metal clusters was confirmed by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry.

Integration of metal-organic frameworks and clay toward functional composite materials.

Metal-organic frameworks (MOFs) have become increasingly important as a class of porous crystalline materials because of their diverse applications. At the same time, significant progress has been achieved in the field of MOF-based composite materials toward novel applications based on the synergistic effect of two or more different components. Clay materials have been explored recently in MOF chemistry for the synthesis of MOF-clay composites, which are a new class of functional materials synthesized by a cooperative combination of MOFs with clay.

Electrically and magnetically readable memory with a graphene/1T-CrTe heterostructure: anomalous Hall transistor.

Using first-principles theoretical analysis, we demonstrate the spin-polarized anomalous Hall conductivity (AHC) response of a 2D vdW heterostructure of graphene and ferromagnetic CrTe that can be controlled with a perpendicular electric field . The origins of AHC and linear magnetoelectric responses are traced to (a) the transfer of electronic charge from graphene to ferromagnetic CrTe causing an out-of-plane electric polarization = 1.69 μC cm and (b) the crystal field and spin-split Dirac points of graphene.

Bioinspired programmable coacervate droplets and self-assembled fibers through pH regulation of monomers.

Phase separation and phase transitions pervade the biological domain, where proteins and RNA engage in liquid-liquid phase separation (LLPS), forming liquid-like membraneless organelles. The misregulation or dysfunction of these proteins culminates in the formation of solid aggregates a liquid-to-solid transition, leading to pathogenic conditions. To decipher the underlying mechanisms, synthetic LLPS has been examined through complex coacervate formation from charged polymers.

Boosting quantum efficiency and suppressing self-absorption in CdS quantum dots through interface engineering.

Applications of photoluminescence (PL) from semiconductor quantum dots (QDs) have faced the dichotomy of excitonic emission being susceptible to self-absorption and shallow defects reducing quantum yield (QY) catastrophically, and doped emissions sacrificing the tunability of the emission wavelength a quantum size effect, making it extremely challenging, if not impossible, to optimize all desirable properties simultaneously. Here we report a strategy that simultaneously optimizes all desirable PL properties in CdS QDs by leveraging interface engineering through the growth of two crystallographic phases, namely wurtzite and zinc blende phases, within individual QDs. These engineered interfaces result in sub-bandgap emissions ultrafast energy transfer (∼780 fs) from band-edge states to interface states protected from surface defects, enhancing stability and prolonging the PL lifetime.

A ratiometric luminescence thermometer based on lanthanide encapsulated complexes.

Lanthanide-containing complexes have been widely developed as ratiometric luminescence thermometers, which are non-invasive, contactless and accurate. The synthesis of these Ln complexes generally requires high temperatures, multiple steps and other harsh conditions. Moreover, bimetallic lanthanide complexes, which have been reported to be better thermometers, are even more challenging to synthesize.

Stretchable hierarchical metal wire networks for neuromorphic emulation of nociception and anti-nociception.

Among biomimetic technologies, the incorporation of sensory hardware holds exceptional utility in human-machine interfacing. In this context, devices receptive to nociception and emulating antinociception gain significance as part of pain management. Here we report, a stretchable two-terminal resistive neuromorphic device consisting of a hierarchical Ag microwire network formed using a crack templating protocol.

Supramolecular Guest Exchange in Cucurbit[7]uril for Bioorthogonal Fluorogenic Imaging across the Visible Spectrum.

Fluorogenic probes that unmask fluorescence signals in response to bioorthogonal reactions are a powerful new addition to biological imaging. They can significantly reduce background fluorescence and minimize nonspecific signals, potentially enabling real-time, high-contrast imaging without the need to wash out excess fluorophores. While diverse classes of highly refined synthetic fluorophores are now readily available, integrating them into a bioorthogonal fluorogenic scheme still requires extensive design efforts and customized structural alterations to optimize quenching mechanisms for each specific fluorophore scaffold.

Role of Covalent Cages and Rattler Atoms in Lowering the Thermal Conductivity in Zintl Metal Chalcogenides.

Zintl phases represent a class of compounds, mainly intermetallics, which are characterized by ionic and covalent bonds in the same crystal. Since its discovery in the late 1800s, Zintl phases have found their importance as an academic interest due to their fascinating structure as well as in industry due to their vast applicability. In recent years, the Zintl phase of metal chalcogenides has further demonstrated its ability as a promising thermoelectric material, primarily due to its intrinsically ultralow lattice thermal conductivity (κ).

A fluorescent probe with serum albumin as a signal amplifier for real-time sensing of HSO in solution, mitochondria of animal cells and rice roots.

Endogenous release of HSO during the enzymatic oxidation of sulfur containing amino acids in mitochondria or insufficiency of sulfite oxidase results in the accumulation of sulfite and thiosulfate in biological fluids affecting mitochondrial homeostasis of brain mitochondria associated with serious clinical symptoms related to neurological disorders. The red fluorescent probe MGQ undergoes self-assembly in water and reveals aggregation induced quenching of fluorescence. MGQ reveals 143-fold and 179-fold increases in fluorescence intensity at 645 nm, respectively, in the presence of HSA and BSA and does not significantly differentiate between two albumins.

Modulating photophysical properties in a flexible porous host by regulating guest-assisted charge transfer interactions.

The 1D array of electron donor-acceptor chromophoric organic molecules is of paramount importance for photovoltaic, catalytic and optoelectronic applications. Herein, we report coordination driven 1D arrays of an electron-donor guest (fluorene, carbazole, dibenzofuran, and dibenzothiophene) and -phen chelator as an acceptor in a Zn-based porous coordination polymer, {[Zn(-phen)(ndc)]·DMF} (PCP-1). All the guest-encapsulated PCPs were characterized by performing single-crystal structure determinations and showed emission driven by charge transfer.

Identification and detection of conserved G-quadruplex in monkeypox virus using conformation specific fluorogenic probe.

Identifying distinct noncanonical structures in pathogenic genomes is crucial for developing new diagnostic tools. This study uncovers stable G-quadruplex (GQ) structures in conserved DNA sequences unique to the monkeypox virus (MPV). Furthermore, we developed a method for the detection of target GQ using a fluorogenic probe.