Evaluation of novel ZnO–Ag cathode for CO2 electroreduction in solid oxide electrolyser

CO₂ and steam/CO₂ electroreduction to CO and methane in solid oxide electrolytic cells (SOEC) has gained major attention in the past few years. This work evaluates, for the very first time, the performance of two different ZnO–Ag cathodes: one where ZnO nanopowder was mixed with Ag powder for preparing the cathode ink (ZnO_mix–Ag cathode) and the other one where Ag cathode was infiltrated with a zinc nitrate solution (ZnO_inf –Ag cathode). ZnO_mix–Ag cathode had a better distribution of ZnO particles throughout the cathode, resulting in almost double CO generation while electrolysing both dry CO₂ and H₂/CO₂ (4:1 v/v). A maximum overall CO₂ conversion of 48% (in H₂/CO₂) at 1.7 V and 700 °C clearly indicated that as low as 5 wt% zinc loading is capable of CO₂ electroreduction. It was further revealed that for ZnO_inf –Ag cathode, most of CO generation took place through RWGS reaction, but for ZnO_mix–Ag cathode, it was the synergistic effect of both RWGS reaction and CO₂ electrolysis. Although ZnO_inf –Ag cathode produced trace amount of methane at higher voltages, with ZnO_mix–Ag cathode, there was absolutely no methane. This seems to be due to strong electronic interaction between Zn and Ag that might have suppressed the catalytic activity of the cathode towards methanation.

     

Studies on the cure parameters of cyanate ester–epoxy blend system through rheological property measurements

Thermosetting blend system of co-cured cyanate ester with epoxy resin is receiving importance for high technological applications because of its wide range of thermo-mechanical, rheological, and electrical properties. However, processing of these system warrant proper knowledge of the rheological behavior of the blend during the curing process. This article discusses the rheological behavior of the blend systems with respect to the pot life, gel time, gelation temperature and also evaluated fitting parameters for the prediction of gelation time and viscosity during the entire curing process from the isothermal rheological measurements.     

Characterization of a Robust CoII Fluorescent Complex Deposited Intact On HOPG

The new diimine fluorescent ligand ACRI‐1 based on a central acridine yellow core is reported along with its coordination complex [Co₂( ACRI‐1 )₂] ( 1 ), a fluorescent weak ferromagnet. Due to the strong fluorescence of the acridine yellow fluorophore, it is not completely quenched when the ligand is coordinated to Co^II. The magnetic properties of bulk complex 1 and its stability in solution have been studied. Complex 1 has been deposited on highly ordered pyrolitic graphite (HOGP) from solution. The thin films prepared have been characterized by AFM, time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS), grazing incidence X‐ray diffraction (GIXRD), X‐ray absorption spectroscopy (XAS), X‐ray magnetic circular dichroism (XMCD) and theoretical calculations. The data show that the complex is robust and remains intact on the surface of graphite.     

Metal‐like Ductility in Organic Plastic Crystals: Role of Molecular Shape and Dihydrogen Bonding Interactions in Aminoboranes

Ductility is a common phenomenon in many metals but is difficult to achieve in molecular crystals. Organic crystals bend plastically on one or two face‐specific directions but fracture when stressed in any other arbitrary directions. An exceptional metal‐like ductility and malleability in the isomorphous crystals of two globular molecules, BH₃NMe₃ and BF₃NMe₃, is reported, with characteristic tensile stretching, compression, twisting, and thinning. The mechanically deformed samples, which transition to lower symmetry phases, retain good long‐range order amenable to structure determination by single‐crystal X‐ray diffraction. Molecules in these high‐symmetry crystals interact through electrostatic forces (B^??N⁺) to form columnar structures with multiple slip planes and weak dispersive forces between columns. On the other hand, the limited number of facile slip planes and strong dihydrogen bonding in BH₃NHMe₂ negates ductility. Our study has implications for the design of soft ferroelectrics, solid electrolytes, barocalorics, and soft robotics.     

DIC Challenge 2.0: Developing Images and Guidelines for Evaluating Accuracy and Resolution of 2D Analyses

Experimental Mechanics - The DIC Challenge 2.0 follows on from the work accomplished in the first Digital Image Correlation (DIC) Challenge Reu et al. (Experimental Mechanics 58(7):1067, 1). The...     

Advantage of Quantum Theory over Nonclassical Models of Communication

Quantum correlations provide dramatic advantage over the corresponding classical resources in several communication tasks. However, a broad class of probabilistic theories exists that attributes greater success than quantum theory in many of these tasks by allowing supra-quantum correlations in “space-like” and/or “time-like” paradigms. In this letter, a communication task involving three spatially separated parties is proposed where one party (verifier) aims to verify whether the bit strings possessed by the other two parties (terminals) are equal or not. This task is called authentication with limited communication, the restrictions on communication being: i) the terminals cannot communicate with each other, but (ii) each of them can communicate with the verifier through single use of channels with limited capacity. Manifestly, classical resources are not sufficient for perfect success of this task. Moreover, it is also not possible to perform this task with certainty in several nonclassical theories although they might possess stronger “space-like” and/or “time-like” correlations. Surprisingly, quantum resources can achieve the perfect winning strategy. The proposed task thus stands apart from all previously known communication tasks as it exhibits quantum advantage over other nonclassical strategies.     

Unusual Surface Latent Heat Flux Variations and Their Critical Dynamics Revealed before Strong Earthquakes

We focus on the possible thermal channel of the well-known Lithosphere–Atmosphere–Ionosphere Coupling (LAIC) mechanism to identify the behavior of thermal anomalies during and prior to strong seismic events. For this, we investigate the variation of Surface Latent Heat Flux (SLHF) as resulting from satellite observables. We demonstrate a spatio-temporal variation in the SLHF before and after a set of strong seismic events occurred in Kathmandu, Nepal, and Kumamoto, Japan, having magnitudes of 7.8, 7.3, and 7.0, respectively. Before the studied earthquake cases, significant enhancements in the SLHF were identified near the epicenters. Additionally, in order to check whether critical dynamics, as the signature of a complex phenomenon such as earthquake preparation, are reflected in the SLHF data, we performed a criticality analysis using the natural time analysis method. The approach to criticality was detected within one week before each mainshock.     

Copper(I) complexes of N-(aryl)pyridine-2-aldimines: Spectral, electrochemical and catalytic properties

The reactions of N-(aryl)pyridine-2-aldimines (L-R; R = OCH₃, CH₃, H, Cl and NO₂), derived from pyridine-2-aldehyde and para-substituted anilines, with CuI in methanol under ambient conditions afford a series of brown complexes of the type [{Cu(L-R)I}₂]. The structure of the [{Cu(L-OCH₃)I}₂] complex has been determined by X-ray crystallography. In these dimeric complexes the two copper centers are linked through an iodo-bridge, and the L-R ligands are coordinated to the metal center through the pyridine-nitrogen and imine-nitrogen. All the complexes show characteristic ¹H NMR signals and intense MLCT transitions in the visible region. These complexes also show an emission near 465 nm, whilst they are excited at 340 nm, with relatively poor quantum yields (φ ∼0.002 at 298 K). Cyclic voltammetry on all the complexes shows two successive Cu(I)-Cu(II) oxidations on the positive side of SCE, and a reduction of the coordinated imine ligand on the negative side. These copper(I) complexes are found to efficiently catalyze Suzuki type C-C coupling reactions.     

Efficacious Anticancer Drug Delivery Mediated by a pH‐Sensitive Self‐Assembly of a Conserved Tripeptide Derived from Tyrosine Kinase NGF Receptor

We present herein a short tripeptide sequence (Lys–Phe–Gly or KFG) that is situated in the juxtamembrane region of the tyrosine kinase nerve growth factor (Trk NGF) receptors. KFG self‐assembles in water and shows a reversible and concentration‐dependent switching of nanostructures from nanospheres (vesicles) to nanotubes, as evidenced by dynamic light scattering, transmission electron microscopy, and atomic force microscopy. The morphology change was associated with a transition in the secondary structure. The tripeptide vesicles have inner aqueous compartments and are stable at pH 7.4 but rupture rapidly at pH≈6. The pH‐sensitive response of the vesicles was exploited for the delivery of a chemotherapeutic anticancer drug, doxorubicin, which resulted in enhanced cytotoxicity for both drug‐sensitive and drug‐resistant cells. Efficient intracellular release of the drug was confirmed by fluorescence‐activated cell sorting analysis, fluorescence microscopy, and confocal microscopy.     

Synthesis of crescent shaped heterocycle-fused aromatics via Garratt-Braverman cyclization and their DNA-binding studies

Three crescent shaped heterocycle-fused phenanthrene based systems 1–3 have been synthesized starting from benzene (or substituted benzene) 1,2-bis-propargyl alcohols. Bis-alkylation with propargylic bromides provided the key intermediate, the bis-propargyl bis-ethers. In spite of the possibility of many competing reactions, the latter underwent facile double Garratt-Braverman cyclization to provide compounds 1–3 in near quantitative yield, in a striking reaction involving the formation of four C–C bonds in a single step. Compounds 1–3 showed binding interaction with DNA, predominantly, via groove binding along with partial intercalation (combilexins). Molecular docking study supported the proposed binding modes.