Publications

Self-healing polymer composites and its chemistry

Simulation of magnetization plateaus of stanene-like nanostructures at low temperatures

2-[(<i>E</i>)-(3,4-Dimethylisoxazol-5-yl)iminomethyl]phenol

The title compound, C(12)H(12)N(2)O(2), has been synthesized by the reaction of 5-amino-3,4-dimethyl-isoxazole and salicyladehyde. The mol-ecule adopts an E configuration about the central C=N double bond. The dihedral angle between the isoxazole and phenyl rings is 4.2 (2)° and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring motif. The crystal studied was a non-merohedral twin with a domain ratio of 0.834 (4):0.166 (4).

Oxidation‐etching induced morphology regulation of Cu catalysts for high‐performance electrochemical <scp>N₂</scp> reduction

Abstract Renewable‐electricity‐driven N 2 reduction is an attractive approach for ambient NH 3 synthesis, but active electrocatalysts are needed to enable the N 2 reduction reaction. Monolithic electrodes with active components anchored on conductive supports provide many advantages like structural stability, large surface area, and low electrical resistance. Here, a novel “oxidation‐etching” strategy is proposed to carve the surface of Cu foam into structures of particles, cubes, and sheets for N 2 reduction electrocatalysis. The optimal catalyst achieves a Faradic efficiency as high as 18% at −0.35 V vs reversible hydrogen electrode (RHE) and a large NH 3 yield of 2.45 × 10 −10 mol s −1 cm −1 at −0.40 V vs RHE in 0.1 M HCl. Notably, it also shows superior long‐term electrochemical durability, with the preservation of electro‐activity for at least 20 hours. image

An Fe(TCNQ)₂nanowire array on Fe foil: an efficient non-noble-metal catalyst for the oxygen evolution reaction in alkaline media

It is highly desirable to develop efficient and durable oxygen evolution reaction (OER) electrocatalysts. Herein, we report the in situ development of an Fe-(tetracyanoquinodimethane)₂ nanowire array on Fe foil (Fe(TCNQ)₂/Fe) via a solution immersion method. As a non-noble-metal OER electrocatalyst, such Fe(TCNQ)₂/Fe needs an overpotential of only 340 mV to drive a geometrical catalytic current density of 10 mA cm^-2 in 1.0 M KOH. Notably, it also shows strong long-term electrochemical durability capable of maintaining its catalytic activity for at least 110 h.

Influence of the Reaction Temperature on the Nature of the Active and Deactivating Species during Methanol to Olefins Conversion over H-SSZ-13

The formation of hydrocarbon species during the methanol to olefins (MTO) reaction over zeolite H-SSZ-13 has been systematically studied at reaction temperatures between 573 and 723 K with a combination of operando UV–vis spectroscopy and online gas chromatography. It was found that the applied reaction temperature influences the rate and nature of coke formation as well as the catalyst stability. Correlation between all hydrocarbon species formed inside the catalyst pores with the activity and deactivation of H-SSZ-13 zeolite material was established. By using a multivariate analysis, we found that the nature of the active and deactivating species varies with the reaction temperature. The majority of active hydrocarbon pool species at low reaction temperatures (i.e., 573–598 K) are methylated benzene carbocations, while at high reaction temperatures (i.e., 623–723 K) methylated naphthalene carbocations become dominant. At low reaction temperatures the deactivation occurs because of the pore filling with methylated naphthalene carbocations. In contrast, at higher reaction temperatures the formation of phenanthrene, pyrene carbocations, and highly conjugated polyaromatics during the deactivation increases. This suggests that the formation of highly conjugated polyaromatics on the external surface can play a role in the deactivation of the material by pore blockage.

Spectral, stoichiometric ratio, physicochemical, polarity and photostability studies of newly synthesized chalcone dye in organized media

CELLULOSE ACETATE/COPPER (II) OXIDE NANOCOMPOSITE FOR SELECTIVE DETECTION AND EXTRACTION OF LEAD (II) IONS

Nanocomposites (NCs) based on cellulose acetate (CA) were prepared by dispersing copper (II) oxide (CuO) nanofillers in the cellulose acetate matrix. Nanocomposites were structurally examined by different spectroscopic techniques. The CA/CuO NCs were immobilized on a silver electrode (AgE) to investigate its chemical sensing behavior toward lead ions by I-V (current vs. voltage) technique. The calibration curve showed good electrical response toward Pb +2 with linearity up to 100 M. The linear range exhibited good sensitivity (213.43 A.cm -2 .mM - ). The electrical performance showed an optimum response at pH 6 and good selectivity toward Pb +2 , compared to the interference of other metal ions. Further, the selectivity of NCs toward different metal ions, including Zn 2+ , Ni 2+ , Pb 2+ , Mn 2+ , Sr 3+ , Al 3+ , Fe 3+ and Ce 3+ , was investigated by inductively coupled plasma optical emission spectroscopy. CA/CuO (3% w/w) displayed higher uptake capacity for Pb 2+ with K d of 344170 mL/g. These data revealed that CA/CuO NCs exhibit high sensitivity and selectivity toward detection and extraction of lead ions and could be used for the efficient removal of Pb 2 .

Magnetron sputtering enabled sustainable synthesis of nanomaterials for energy electrocatalysis

This review summarizes recent advances in developing sputtered nanomaterials as catalysts for energy electrocatalysis. In-depth insights into architecture/compositional design, synthesis, mechanism, and performance are provided.

Catalytic efficiency of copper nanoparticles modified silica-alginate hydrogel nanocomposite towards reduction of water pollutants and H2 generation

Synthesis of metal oxide composite nanosheets and their pressure sensing properties

This study presents the synthesis of metal oxides composite nanosheets (oxides of cobalt, zinc and iron) and their pressure sensing properties. A transducer has been fabricated to directly measure the resistance—pressure and impedance—pressure relationships of pristine nanopowder. At the initial stage, a nanopowder sample of 10 mm diameter and 1 mm height was placed in the transducer and by applying pressure of up to 8.15 kN/m2; the DC resistance and the impedance are reduced by 44% on average. It can be explained by the densification of the samples and a decrease in porosity due to the effect of pressure. It was also observed that the DC resistance increases with time and saturated within 8 min. It is considered that this phenomenon is based on the effect of displacement currents of bound charges. The dependences of the impedance phase (θ) on frequency and pressure have also been investigated.

Efficient Vapor‐Phase Selective Hydrogenolysis of Bio‐Levulinic Acid to γ‐Valerolactone Using Cu Supported on Hydrotalcite Catalysts

In this work, Cu nanoparticles (Cu NPs, 2-20 nm) supported on Hydrotalcite catalysts exhibit enhanced selectivity for γ-valerolactone (GVL) during hydrogenolysis of levulinic acid (LA). At 260 °C, over 3 wt% Cu achieved 87.5% of LA conversion with a maximum GVL selectivity (95%). In contrast, LA hydrogenolysis over 3Cu/Hydrotalcite catalyst is highly active and stable toward the production of GVL due to balanced acido-basicity and higher Cu dispersion with ultrasmall particle sizes, which are investigated through the temperature programmed desorption (TPD) of ammonia, N₂O titration, and transmission electron microscopy (TEM) analysis. Hydrotalcite in combination with inexpensive Cu catalyst is found to be an efficient and environmentally benign for LA hydrogenolysis.

The effect of γ-ray-irradiated conducting polymer electrolyte and its application of dye-sensitized solar cells to building window glass system

CCDC 1026537: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Catalyst-free facile synthesis of 2-substituted benzothiazoles

2-Substituted benzothiazoles were synthesized in excellent yields by a benzotriazole methodology, with the conditions being efficient, green, economical, and suitable for broad applications in medicinal chemistry and the synthesis of specialty chemicals.

Se-modified polymeric carbon nitride nanosheets with improved photocatalytic activities

CCDC 1989095: Experimental Crystal Structure Determination

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Spectroscopic investigation on kinetics and mechanistic aspects to electron-transfer process into quinolinium dichromate oxidation of a high blood pressure drug captopril in acidic medium