BINA

With an increasing demand for high-energy-density lithium-ion batteries (LIBs), nickel-rich cathodes such as LiNi0.9Mn0.05Co0.05O2 (NMC90) have gained significant interest due to their relatively low cobalt and high specific energy. However, cycling stability is compromised due to parasitic reactions at the electrode–electrolyte interfaces of NMC90. Herein, we demonstrate improved electrochemical properties of NMC90 using di-tert-butylmethyl adamantoyl silane (RSiCOAd: R is tBu(CH3)2 and Ad is 1-Ad) as an additive in a commercial electrolyte. Upon detailed electrochemical and spectroscopic analysis, we demonstrate that the RSiCOAd additive undergoes in situ decomposition to form a fluorinated organosiloxane passivation layer on the NMC90 surface and enhanced fluorination on the lithium anode surface. This phenomenon could significantly mitigate the parasitic reactions at the cathode–electrolyte …

Rechargeable magnesium batteries (RMBs) have the potential to contribute towards alternative energy storage due to their low cost, high abundance, dendrites free deposition of Mg and high volumetric energy density. Organometallic complex-based electrolytes in ethereal solutions have been extensively studied in the context of RMBs due to their ability to facilitate highly reversible magnesium deposition in rechargeable magnesium batteries, while demonstrating wide enough electrochemical stability windows. However, these solutions containing unique mixture of organo-halo aluminate complexes have detrimental effect on the anodic stability of metallic current collectors for cathodes, like Ni and Al foils. In this work, we were able to synthesize and isolate Mg 2 Cl 3 (THF) 6 Ph 2 AlCl 2/THF electrolyte as the sole electroactive species using simple precursors: Ph 2 AlCl and MgCl 2 in THF, via atom efficient mono …

The electrocatalytic oxygen evolution reaction (OER) is an arduous step in water splitting due to its slow reaction rate and large overpotential. Herein, we synthesized glycerate-anion-intercalated nickel–iron glycerates (NiFeGs) using a one-step solvothermal reaction. We designed various NiFeGs by tuning the molar ratio between Ni and Fe to obtain Ni4Fe1G, Ni3Fe1G, Ni3Fe2G, and Ni1Fe1G, which we tested for their OER performance. We initially analyzed the catalytic performance of powder samples immobilized on glassy carbon electrodes using a binder. Ni3Fe2G outperformed the other NiFeG compositions, including NiFe layered double hydroxide (LDH). It exhibited an overpotential of 320 mV at a current density of 10 mA cm–2 in an electrolytic solution of pH 14. We then synthesized carbon paper (CP)-modified Ni3Fe2G as a self-supported electrode (Ni3Fe2G/CP), and it exhibited a high current density (100 mA cm−2) at a low overpotential of 300 mV. The redox peak analysis for the NiFeGs revealed that the initial step of the OER is the formation of γ-NiOOH, which was further confirmed by a post-Raman analysis. We extensively analyzed the catalyst’s stability and lifetime, the nature of the active sites, and the role of the Fe content to enhance the OER performance. This work may provide the motivation to study metal-alkoxide-based efficient OER electrocatalysts that can be used for alkaline water electrolyzer applications.

Stretched-exponential relaxation is a widely observed phenomenon found in ordered ferromagnets as well as glassy systems. One modeling approach connects this behavior to a droplet dynamics described by an effective Langevin equation for the droplet radius with an r 2/3 potential. Here, we study a Brownian particle under the influence of a general confining, albeit weak, potential field that grows with distance as a sublinear power law. We find that for this memoryless model, observables display stretched-exponential relaxation. The probability density function of the system is studied using a rate-function ansatz. We obtain analytically the stretched-exponential exponent along with an anomalous power-law scaling of length with time. The rate function exhibits a point of nonanalyticity, indicating a dynamical phase transition. In particular, the rate function is double valued both to the left and right of this point …

Water pollution caused by hazardous substances, particularly heavy metal (HM) ions, poses a threat to human health and the environment. Traditional methods for measuring HM in water are expensive and time-consuming and require extensive sample preparation. Therefore, developing robust, simple, and sensitive techniques for the detection and classification of HM is needed. We propose an optical approach that exploits the full scattering profile, meaning the angular intensity distribution, and utilizes the iso-pathlength (IPL) point. This point appears where the intensity is constant for different scattering coefficients, while the absorption coefficient is set. The absorption does not affect the IPL point position, it only reduces its intensity. In this paper, we explore the wavelength influence on the IPL point both in Monte Carlo simulations and experimentally. Next, we present the characterization of ferric chloride (FeCl2 …

Understanding enzyme mechanisms is essential for unraveling the complex molecular machinery of life. In this review, we survey the field of computational enzymology, highlighting key principles governing enzyme mechanisms and discussing ongoing challenges and promising advances. Over the years, computer simulations have become indispensable in the study of enzyme mechanisms, with the integration of experimental and computational exploration now established as a holistic approach to gain deep insights into enzymatic catalysis. Numerous studies have demonstrated the power of computer simulations in characterizing reaction pathways, transition states, substrate selectivity, product distribution, and dynamic conformational changes for various enzymes. Nevertheless, significant challenges remain in investigating the mechanisms of complex multistep reactions, large-scale conformational changes …

Rechargeable magnesium batteries (RMBs) have the potential to contribute towards alternative energy storage due to their low cost, high abundance, dendrites free deposition of Mg and high volumetric energy density. Organometallic complex-based electrolytes in ethereal solutions have been extensively studied in the context of RMBs due to their ability to facilitate highly reversible magnesium deposition in rechargeable magnesium batteries, while demonstrating wide enough electrochemical stability windows. However, these solutions containing unique mixture of organo-halo aluminate complexes have detrimental effect on the anodic stability of metallic current collectors for cathodes, like Ni and Al foils. In this work, we were able to synthesize and isolate Mg 2 Cl 3 (THF) 6 Ph 2 AlCl 2/THF electrolyte as the sole electroactive species using simple precursors: Ph 2 AlCl and MgCl 2 in THF, via atom efficient mono …

Rechargeable magnesium batteries (RMBs) have the potential to contribute towards alternative energy storage due to their low cost, high abundance, dendrites free deposition of Mg and high volumetric energy density. Organometallic complex-based electrolytes in ethereal solutions have been extensively studied in the context of RMBs due to their ability to facilitate highly reversible magnesium deposition in rechargeable magnesium batteries, while demonstrating wide enough electrochemical stability windows. However, these solutions containing unique mixture of organo-halo aluminate complexes have detrimental effect on the anodic stability of metallic current collectors for cathodes, like Ni and Al foils. In this work, we were able to synthesize and isolate Mg2Cl3(THF)(6)Ph2AlCl2/THF electrolyte as the sole electroactive species using simple precursors: Ph2AlCl and MgCl2 in THF, via atom efficient mono …

We investigate a quantum walk on a ring represented by a directed triangle graph with complex edge weights and monitored at a constant rate until the quantum walker is detected. To this end, the first hitting time statistics is recorded using unitary dynamics interspersed stroboscopically by measurements, which is implemented on IBM quantum computers with a midcircuit readout option. Unlike classical hitting times, the statistical aspect of the problem depends on the way we construct the measured path, an effect that we quantify experimentally. First, we experimentally verify the theoretical prediction that the mean return time to a target state is quantized, with abrupt discontinuities found for specific sampling times and other control parameters, which has a well-known topological interpretation. Second, depending on the initial state, system parameters, and measurement protocol, the detection probability can be …

Second-order superlattices form when moir\'e superlattices of similar dimensions interfere with each other, leading to even larger superlattice periodicities. These crystalline structures have been engineered utilizing two-dimensional (2D) materials such as graphene and hexagonal boron nitride (hBN) under specific alignment conditions. Such specific alignment has shown to play a crucial role in facilitating correlation-driven topological phases featuring the quantized anomalous Hall effect. While signatures of second-order superlattices have been found in transport experiments, any real-space visualization is lacking to date. In this work, we present cryogenic nanoscale photovoltage (PV) measurements that reveal a second-order superlattice in magic-angle twisted bilayer graphene (MATBG) closely aligned to hBN. This is evidenced by long-range periodic photovoltage modulations across the entire sample backed by corresponding electronic transport features. Our theoretical framework shows that small strain- or twist-angle variations can lead to a drastic shift between a local one-dimensional, square or triangular superlattices. Our real-space observations shed new light on the mechanisms responsible for breaking spatial symmetries in TBG and pave an avenue to engineer long-range superlattice structures in 2D materials.

Rechargeable magnesium batteries (RMBs) have the potential to contribute towards alternative energy storage due to their low cost, high abundance, dendrites free deposition of Mg and high volumetric energy density. Organometallic complex-based electrolytes in ethereal solutions have been extensively studied in the context of RMBs due to their ability to facilitate highly reversible magnesium deposition in rechargeable magnesium batteries, while demonstrating wide enough electrochemical stability windows. However, these solutions containing unique mixture of organo-halo aluminate complexes have detrimental effect on the anodic stability of metallic current collectors for cathodes, like Ni and Al foils. In this work, we were able to synthesize and isolate Mg 2 Cl 3 (THF) 6 Ph 2 AlCl 2/THF electrolyte as the sole electroactive species using simple precursors: Ph 2 AlCl and MgCl 2 in THF, via atom efficient mono …

IntroductionAnalysis of an individual’s immunoglobulin (IG) gene repertoire requires the use of high-quality germline gene reference sets. When sets only contain alleles supported by strong evidence, AIRR sequencing (AIRR-seq) data analysis is more accurate and studies of the evolution of IG genes, their allelic variants and the expressed immune repertoire is therefore facilitated.MethodsThe Adaptive Immune Receptor Repertoire Community (AIRR-C) IG Reference Sets have been developed by including only human IG heavy and light chain alleles that have been confirmed by evidence from multiple high-quality sources. To further improve AIRR-seq analysis, some alleles have been extended to deal with short 3’ or 5’ truncations that can lead them to be overlooked by alignment utilities. To avoid other challenges for analysis programs, exact paralogs (e.g. IGHV1-69*01 and IGHV1-69D*01) are only represented once in each set, though alternative sequence names are noted in accompanying metadata.Results and discussionThe Reference Sets include less than half the previously recognised IG alleles (e.g. just 198 IGHV sequences), and also include a number of novel alleles: 8 IGHV alleles, 2 IGKV alleles and 5 IGLV alleles. Despite their smaller sizes, erroneous calls were eliminated, and excellent coverage was achieved when a set of repertoires comprising over 4 million V(D)J rearrangements from 99 individuals were analyzed using the Sets. The version-tracked AIRR-C IG Reference Sets are freely available at the OGRDB website (https://ogrdb.airr-community.org/germline_sets/Human) and will be regularly updated to include newly …

Compressing light into nanocavities substantially enhances light–matter interactions, which has been a major driver for nanostructured materials research. However, extreme confinement generally comes at the cost of absorption and low resonator quality factors. Here we suggest an alternative optical multimodal confinement mechanism, unlocking the potential of hyperbolic phonon polaritons in isotopically pure hexagonal boron nitride. We produce deep-subwavelength cavities and demonstrate several orders of magnitude improvement in confinement, with estimated Purcell factors exceeding 108 and quality factors in the 50–480 range, values approaching the intrinsic quality factor of hexagonal boron nitride polaritons. Intriguingly, the quality factors we obtain exceed the maximum predicted by impedance-mismatch considerations, indicating that confinement is boosted by higher-order modes. We expect that our …

This review focuses on the application of nuclear magnetic resonance (NMR) spectroscopy in the study of lithium and sodium battery electrolytes. Lithium-ion batteries are widely used in electronic devices, electric vehicles, and renewable energy systems due to their high energy density, long cycle life, and low self-discharge rate. The sodium analog is still in the research phase, but has significant potential for future development. In both cases, the electrolyte plays a critical role in the performance and safety of these batteries. NMR spectroscopy provides a non-invasive and non-destructive method for investigating the structure, dynamics, and interactions of the electrolyte components, including the salts, solvents, and additives, at the molecular level. This work attempts to give a nearly comprehensive overview of the ways that NMR spectroscopy, both liquid and solid state, has been used in past and present studies …

Hard x-ray imaging is indispensable across diverse fields owing to its high penetrability. However, the resolution of traditional x-ray imaging modalities, such as computed tomography (CT) systems, is constrained by factors including beam properties, the absence of optical components, and detection resolution. As a result, typical resolution in commercial imaging systems is limited to a few hundred microns. This study advances high-photon-energy imaging by extending the concept of computational ghost imaging to multipixel ghost imaging with x-rays. We demonstrate a remarkable enhancement in resolution from 500 microns to approximately 20 microns for an image spanning 0.9 by 1 cm^2, comprised of 400,000 pixels and involving only 1000 realizations. Furthermore, we present a high-resolution CT reconstruction using our method, revealing enhanced visibility and resolution. Our achievement is facilitated by an innovative x-ray lithography technique and the computed tiling of images captured by each detector pixel. Importantly, this method can be scaled up for larger images without sacrificing the short measurement time, thereby opening intriguing possibilities for noninvasive high-resolution imaging of small features that are invisible with the present modalities.

With an increasing demand for high-energy-density lithium-ion batteries (LIBs), nickel-rich cathodes such as LiNi0.9Mn0.05Co0.05O2 (NMC90) have gained significant interest due to their relatively low cobalt and high specific energy. However, cycling stability is compromised due to parasitic reactions at the electrode–electrolyte interfaces of NMC90. Herein, we demonstrate improved electrochemical properties of NMC90 using di-tert-butylmethyl adamantoyl silane (RSiCOAd: R is tBu(CH3)2 and Ad is 1-Ad) as an additive in a commercial electrolyte. Upon detailed electrochemical and spectroscopic analysis, we demonstrate that the RSiCOAd additive undergoes in situ decomposition to form a fluorinated organosiloxane passivation layer on the NMC90 surface and enhanced fluorination on the lithium anode surface. This phenomenon could significantly mitigate the parasitic reactions at the cathode–electrolyte …

Carbon dots (CDs) with an average diameter of 6.3 nm were synthesized from the medicinal seed extract of Syzygium cumini L. using one-pot hydrothermal synthesis. The prepared CDs exhibited excitation-dependent emission characteristics with photoluminescence (PL) emission maxima at an excitation of 340 nm. The CDs at 500 µg/mL displayed antimicrobial activities against four common pathogens. Both Staphylococcus aureus and S. epidermidis were completely eradicated by CDs within 12 h, compared to 24 h for Escherichia coli and Klebsiella pneumonia. The release of various oxygen species (ROS) was postulated to play a critical role in bacterial eradication. The CDs decorated on cotton fabric by ultrasonication also displayed good antibacterial activities against the above bacteria. The finding opens a plausible use of CDs in biomedical textiles with potent antimicrobial properties against both Gram …

Superparamagnetic nanoparticle-arrested hydrogel matrices have immense significance in smart soft biomaterials. Herein, we report the synthesis of superparamagnetic nanoparticle-loaded magneto-responsive tough elastomeric hydrogels for dual-responsive drug delivery. In the first phase of work, we carried out room-temperature synthesis of amine-functionalized superparamagnetic iron oxide nanoparticles (IONPs), and in the second phase of work, we demonstrated that IONPs could act as a toughening agent as well as a viscosity modifier for poly(acrylic acid-co-hydroxyethyl methacrylate) copolymer hydrogels. The hydrogel was tested by Fourier transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and continuous-wave-electron paramagnetic resonance (CW-EPR). Moreover, the IONPs affect its gelation time and elasticity significantly, which was also evaluated from its …

We investigate a quantum walk on a ring represented by a directed triangle graph with complex edge weights and monitored at a constant rate until the quantum walker is detected. To this end, the first hitting time statistics is recorded using unitary dynamics interspersed stroboscopically by measurements, which is implemented on IBM quantum computers with a midcircuit readout option. Unlike classical hitting times, the statistical aspect of the problem depends on the way we construct the measured path, an effect that we quantify experimentally. First, we experimentally verify the theoretical prediction that the mean return time to a target state is quantized, with abrupt discontinuities found for specific sampling times and other control parameters, which has a well-known topological interpretation. Second, depending on the initial state, system parameters, and measurement protocol, the detection probability can be less than one or even zero, which is related to dark-state physics. Both, return-time quantization and the appearance of the dark states are related to degeneracies in the eigenvalues of the unitary time evolution operator. We conclude that, for the IBM quantum computer under study, the first hitting times of monitored quantum walks are resilient to noise. Yet, finite resolution effects lead to new topological, chirality, and broadening effects, which disappear in the asymptotic theory with an infinite number of measurements. Our results point the way for the development of novel quantum walk algorithms that exploit measurement-induced effects on quantum computers.

Conformational dynamics of individual biomolecules have been reported using confocal-based single molecule fluorescence spectroscopy on timescale from nanoseconds to seconds. The data, a list of photon arrival times and detector IDs, can contain several distinct parameters observed simultaneously, such as FRET ratio, polarization ratio, and fluorescence lifetime. Identifying dynamics reflecting conformational changes in this data, however, can be difficult, especially when the dynamics are faster than the few milliseconds it takes for a single molecule to traverse the confocal excitation volume. We demonstrate an extension to the previously developed photon-by-photon hidden Markov modeling (H 2 MM) multi-parameter H 2 MM (mpH 2 MM) as a general and efficient method for extracting fast dynamics from both FRET and PIFE based studies. We demonstrate that H 2 MM can accept number of photon types …

Phase retardation is a cornerstone of modern optics, yet, at mid-infrared (mid-IR) frequencies, it remains a major challenge due to the scarcity of simultaneously transparent and birefringent crystals. Most materials resonantly absorb due to lattice vibrations occurring at mid-IR frequencies, and natural birefringence is weak, calling for hundreds of microns to millimeters-thick phase retarders for sufficient polarization rotation. Here, we demonstrate mid-IR phase retardation with flakes of α-MoO3 that are more than ten times thinner than the operational wavelength, achieving 90 degrees polarization rotation within one micrometer of material. We report conversion ratios above 50% in reflection or transmission mode, and wavelength tunability by several micrometers. Our results showcase that exfoliated flakes of low-dimensional crystals can serve as a platform for mid-IR miniaturized integrated low-loss polarization control.