Electrochemical Reduction of Nitrogen to Ammonia Using Zinc Telluride.

Electrosynthesis of ammonia (NH), an important constituent molecule of various commercial fertilizers, is a promising and sustainable alternative strategy compared with the century-old Haber-Bosch process. Herein, zinc telluride (ZnTe) is demonstrated as an efficient electrocatalyst for reducing nitrogen (N) under ambient conditions to NH. In this simple chemical strategy, Zn preferentially binds N over hydrogen (H), and Te, by virtue of its superior electronic properties, enhances the electrocatalytic activity of ZnTe.

spectroscopy investigations of the redox reactions in heme and heme-proteins.

spectroscopic investigations during molecular redox processes provide unique insights into complex molecular structures and their transformations. Herein, a combination of a potentiodynamic method with spectroscopy has been employed to holistically investigate the structural transformations during Fe-redox (Fe ↔ Fe) of hemin vis á vis heme-proteins, myoglobin (Mb), hemoglobin (Hb) and cytochrome- (Cyt-). The UV-vis findings reveal the formation of hemozoin (≈heme-dimer), which can be selectively prevented a high concentration of strongly interacting ligands, histidine (the fifth coordinating ligand in the heme-based protein).

Exploring Cu-Doped CoO Bifunctional Oxygen Electrocatalysts for Aqueous Zn-Air Batteries.

The efficiency of oxygen electrocatalysis is a key factor in diverse energy domain applications, including the performance of metal-air batteries, such as aqueous Zinc (Zn)-air batteries. We demonstrate here that the doping of cobalt oxide with optimal amounts of copper (abbreviated as Cu-doped CoO) results in a stable and efficient bifunctional electrocatalyst for oxygen reduction (ORR) and evolution (OER) reactions in aqueous Zn-air batteries. At high Cu-doping concentrations (≥5%), phase segregation occurs with the simultaneous presence of CoO and copper oxide (CuO).

Efficient Rechargeable Li-CO Battery with a Liquid Electrolyte-Soluble CuCl Electrocatalyst.

We demonstrate here a simple liquid electrolyte soluble Cu-compound, viz., cupric chloride (CuCl) as an alternative electrocatalyst for nonaqueous Li-CO batteries. The key point behind the selection of CuCl is that the theoretical potential of Li-CO batteries (≈2.

Probing the Function of a Li-CO Battery with a MXene/Graphene Oxide Composite Cathode Electrocatalyst.

We systematically diagnose here the various phases formed at the electrodes in a Li-CO battery. The CO cathode comprises a mixture of two-dimensional electrocatalysts, MXene and graphene oxide (MXene/GO), configured on Ni foam. The observed overpotential for MXene/GO (2.

Transition Metal Phthalocyanines as Redox Mediators in Li-O Batteries: A Combined Experimental and Theoretical Study of the Influence of 3d Electrons in Redox Mediation.

Redox mediation is an innovative strategy for ensuring efficient energy harvesting from metal-oxygen systems. This work presents a systematic exploratory analysis of first-row transition-metal phthalocyanines as solution-state redox mediators for lithium-oxygen batteries. Our findings, based on experiment and theory, convincingly demonstrate that d (Mn), d (Co), and d (Ni) configurations function better compared to d (Fe) and d (Cu) in redox mediation of the discharge step.

Structure-Redox Response Correlation in a Few Select Heme Systems Using X-ray Absorption Spectroelectrochemistry.

Heme based biomolecules control some of the most crucial life processes, such as oxygen and electron transport during respiration and energy metabolism, respectively. The active site of the heme, viz., the metal center, plays a key role and attributes functionality to these biomolecules.

Thermodynamic Insights into Polymorphism-Driven Lithium-Ion Storage in Monoelemental 2D Materials.

Monoelemental two-dimensional materials (borophene, silicene, etc.) are exciting candidates for electrodes in lithium-ion batteries because of their ultralight molar mass. However, these materials' lithium-ion binding mechanism can be complex as the inherited polymorphism may induce phase changes during the charge-discharge cycles.

Hemoglobin Dynamics in Solution vis-à-vis Under Confinement: An Electrochemical Perspective.

Confining heme protein often leads to beneficial functionalities such as an enhanced electrochemical response from the heme center. This can be harnessed to design effective biosensors for medical diagnostics. Proteins under confinement, to be precise, have more ordered and monodisperse structure compared to the protein in bulk solution.

Probing the Extent of Polysulfide Confinement Using a CoNiS Additive Inside a Sulfur Cathode of a Na/Li-Sulfur Rechargeable Battery.

The extent of confinement of soluble metal polysulfides inside a sulfur cathode strongly determines the performance of metal-sulfur rechargeable batteries. This challenge has been largely tackled by loading sulfur inside various conducting porous scaffolds. However, this approach has not proven to be fully effective because of poor chemical interaction between the scaffold and polysulfides.

Planar Heterojunction Solar Cell Employing a Single-Source Precursor Solution-Processed SbS Thin Film as the Light Absorber.

We discuss here a solution-processed thin film of antimony trisulphide (SbS; band gap ≈ 1.7 eV; electronic configuration: nsnp) for applications in planar heterojunction (PHJ) solar cells. An alternative solution processing method involving a single-metal organic precursor, viz.

Studying Hemoglobin and a Bare Metal-Porphyrin Complex Immobilized on Functionalized Silicon Surfaces Using Synchrotron X-ray Reflectivity.

We evaluate here, using synchrotron X-ray reflectivity, hemoglobin adsorption characteristics on silicon substrates with varying chemical functionalities. Hemoglobin at isoelectronic point and at negative charge is immobilized on functionalized hydrophilic (hydroxyl, carboxylic, amine) and hydrophobic (alkylated) silicon surfaces for the study. As a control, the bare cofactor hemin (containing only the metal and porphyrin with no amino acid residues) is also studied under similar conditions.

Time-Temperature Scaling and Dielectric Modeling of Conductivity Spectra of Single-Ion Conducting Liquid Dendrimer Electrolytes.

We discuss here the time-temperature scaling and dielectric modeling of the variation of single-ion conductivity with frequency of first generation (G) liquid dendrimer electrolyte, viz., Poly(propyl ether imine) (PETIM):Li-salt. The PETIM:Li-salt electrolyte exhibits a cation/anion transference number close to unity in the liquid state.

Using porphyrin-amino acid pairs to model the electrochemistry of heme proteins: experimental and theoretical investigations.

Quasi reversibility in electrochemical cycling between different oxidation states of iron is an often seen characteristic of iron containing heme proteins that bind dioxygen. Surprisingly, the system becomes fully reversible in the bare iron-porphyrin complex: hemin. This leads to the speculation that the polypeptide bulk (globin) around the iron-porphyrin active site in these heme proteins is probably responsible for the electrochemical quasi reversibility.

Unique Features of Metformin: A Combined Experimental, Theoretical, and Simulation Study of Its Structure, Dynamics, and Interaction Energetics with DNA Grooves.

There are certain small molecules that exhibit extraordinarily diverse biological activities. Metformin is one of them. It is widely used as an antidiabetic drug for type-two diabetes.

Determination of Redox Sensitivity in Structurally Similar Biological Redox Sensors.

Redox stimuli govern a variety of biological processes. The relative sensitivity of redox sensors plays an important role in providing a calibrated response to environmental stimuli and cellular homeostasis. This cellular machinery plays a crucial role in the human pathogen Mycobacterium tuberculosis as it encounters diverse microenvironments in the host.

Stepwise Construction of Self-Assembled Heterometallic Cages Showing High Proton Conductivity.

Two neutral tripodal metalloligands (CoL and FeL where L=C H N ) containing a clathrochelate core were synthesized and characterized in one-step. Reactions of these ligands with three different metal acceptors cis-(tmen)Pd(NO ) (tmen = tetramethylethylenediamine), Zn(NO ) and Mn(ClO ) separately yielded a series of heterometallic coordination cages (1 a-3 a and 1 b-3 b) in high yields. Depending on the nature of coordination geometry of the acceptors, the resulting assemblies have trigonal- bipyramidal (1 a/1 b), open-cubic (2 a/2 b), and closed-cubic structures (3 a/3 b).

Ion Transport Mechanism of a Gel Electrolyte Comprising a Salt in Binary Plastic Crystalline Mixtures Confined inside a Polymer Network.

We discuss here the ion transport mechanism of a gel electrolyte comprising lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) solvated by two plastic crystalline solvents, one a solid (succinonitrile, abbreviated as SN) and another (a room temperature ionic liquid) (1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, (abbreviated as IL) confined inside a linear network of poly(methyl methacrylate) (PMMA). The concentration of the IL component (x) determines the physical properties of the unconfined electrolyte (i.e.

Probing the pseudo-1-D ion diffusion in lithium titanium niobate anode for Li-ion battery.

Comprehensive understanding of the charge transport mechanism in the intrinsic structure of an electrode material is essential in accounting for its electrochemical performance. We present here systematic experimental and theoretical investigations of Li(+)-ion diffusion in a novel layered material, viz. lithium titanium niobate.

Tungsten Trioxide (WO3) Nanoparticles as a New Anode Material for Sodium-Ion Batteries.

Tungsten trioxide (WO3) is investigated for the first time as an anode material for sodium-ion batteries. Pristine WO3 displays a discharge potential plateau at 1 V and exhibits a 1st discharge cycle sodium storage capacity of 640 mAh g-1. Electronic wiring of WO3 with graphene oxide (GO, 1% by weight) led to a significant increase in the storage capacity and cyclability of WO3.