Publications

Enhanced electrooxidation of urea using NiMoO4·xH2O nanosheet arrays on Ni foam as anode

Benign separation, adsorption, and recovery of rare-earth Yb(III) ions with specific ligand-based composite adsorbent

This study developed a ligand-based composite adsorbent (ComA) for efficient Ytterbium (Yb(III)) adsorption and recovery from waste samples. The organic ligand of 1E,1`E,1``E,1```E (tetrakis(3-carboxysalicylidene)) naphthalene-1,2,5,5-tetramine (TSNT) was synthesized and TSTN was successfully immobilized onto mesoporous silica by a direct immobilization approach. The experiment conditions were optimized based on contact time, solution acidity, initial Pb(II) concentration pH value, and diverse metal salt concentrations. The Europium (Eu(III)) ion was selected from the lanthanides (Ln(III)) series for green and robust adsorption and recovery based on the adsorption, complexation, and selectivity tendency from the standpoint of the pH-dependent factor. The chemical compound of TSTN consisted of O- and N-donor atoms and was able to make stable complexation with Ln(III) ions in optimum conditions due to the open functionality of the ComA. The experimental data revealed that the maximum Yb(III) adsorption was possible at pH 5.0. The presence of other cations and anions did not adversely affect the Yb(III) capturing by the adsorbent. The bonding mechanism suggested that O- and N-donor atoms of TSTN were strongly coordinated to Eu(III) with a 2:1 ratio complexation. The maximum adsorption capacity was determined to be as high as 149.27 mg/g. The extraction of Yb(III) ions from the saturated adsorbent was possible with 0.25 M HNO3. The regenerated adsorbent that remained maintained the high selectivity to Yb(III) ions and exhibited almost the same adsorption capacity as that of the original adsorbent. However, the adsorption efficiency slightly decreased after several cycles. Therefore, the proposed adsorbent offered a cost-effective material and may be considered a viable alternative for effective adsorption and recovery of Yb(III) ions from water samples.

Application of Agroforestry Waste Biomass Adsorption Materials in Water Pollution Treatment

Carbon nanobelts as a novel sensing platform for fluorescence-enhanced DNA detection

The present communication demonstrates for the first time that carbon nanobelts (CNBs) were facilely synthesized on a large scale via pyrolysis of a 1,8-diaminonaphthalene (DAN)-NiCl2·6H2O mixture under Ar followed by acid leaching. We further demonstrate that such CNBs can be used as a novel effective fluorescent sensing platform for DNA. This sensing platform exhibits high selectivity and sensitivity with a detection limit of 5 nM.

Bulk Heterojunction Tandem Photoelectric Cell Based on p-Si and Phthalocyanine

An organic-inorganic (p-Si and phthalocyanine) hybrid tandem heterojunction Ag/p-Si/AlPc:H2Pc/ITO photoelectric cell was fabricated by pressing technology using preliminary vapor deposited heterojunction films of mixed aluminum-phthalocyanine (AlPc) and metal free phthalocyanine (H2Pc) on p-Si substrate and on ITO coated plastic substrate. By keeping organic films face to face both substrates were pressed and fixed together by adhesive at elevated temperature. Total thickness of the AlPc and H2Pc films were equal to 300 nm. On the back side of p-Si substrate the Ag film was deposited. The device architecture was the following: Ag/p-Si/AlPc:H2Pc/ITO. The morphology of the organic semiconductors film was investigated by AFM. The optical properties of the AlPc:H2Pc film were studied by UV-visible spectroscope. Current-Voltage characteristics were measured in dark and also illumination conditions. Under illumination of 296 W/m(2) the values of V-oc, I-SC, FF and efficiency were equal to 0.5 V, 4 mA, 0.45 and 0.61 %, respectively. The I-V and P-V characteristics of the solar cell were simulated by using Shockley equation and its Newton Raphson solution, respectively for dark and illumination conditions. The obtained simulated results were in good agreement with the experimental results.

Initial Carbon–Carbon Bond Formation during the Early Stages of the Methanol‐to‐Olefin Process Proven by Zeolite‐Trapped Acetate and Methyl Acetate

Abstract Methanol‐to‐olefin (MTO) catalysis is a very active field of research because there is a wide variety of sometimes conflicting mechanistic proposals. An example is the ongoing discussion on the initial C−C bond formation from methanol during the induction period of the MTO process. By employing a combination of solid‐state NMR spectroscopy with UV/Vis diffuse reflectance spectroscopy and mass spectrometry on an active H‐SAPO‐34 catalyst, we provide spectroscopic evidence for the formation of surface acetate and methyl acetate, as well as dimethoxymethane during the MTO process. As a consequence, new insights in the formation of the first C−C bond are provided, suggesting a direct mechanism may be operative, at least in the early stages of the MTO reaction.

Synthesis of <i>N</i>-Methylspiropyrrolidine Hybrids for Their Structural Characterization, Biological and Molecular Docking Studies

A set of novel N-methylspiropyrrolidine hybrids have been synthesized regio selectively employing 1,3-dipolar cycloaddition reaction of substituted chalcones with azomethine ylides (work up in situ from isatin and sarcosine). The spiropyrrolidines structures were studied using FT-IR, 1H and 13C NMR spectroscopic data, and was finally confirmed by X-ray diffraction study. Hirshfeld surface analysis was correlated with X-ray diffraction and described different intermolecular contacts. Good antibacterial activity was reported against gram-positive and gram-negative bacterial strains of Bacillus subtillis, Enterococcus faecalis, E. coli, and Pseudomonas aeruginosa. Initially, antibacterial activity of compounds was confirmed by the zone of inhibition. Most of the compounds have shown MIC and MBC in the range between 50-200 µg∕mL against both types of bacteria. Further, for mechanism of action, the tested compounds were checked for the inhibition of an established bacterial drug target, DNA gyrase using in silico approaches.

Optical Absorption Spectra and Electronic Properties of Symmetric and Asymmetric Squaraine Dyes for Use in DSSC Solar Cells: DFT and TD-DFT Studies

The electronic absorption spectra, ground-state geometries and electronic structures of symmetric and asymmetric squaraine dyes (SQD1-SQD4) were investigated using density functional theory (DFT) and time-dependent (TD-DFT) density functional theory at the B3LYP/6-311++G** level. The calculated ground-state geometries reveal pronounced conjugation in these dyes. Long-range corrected time dependent density functionals Perdew, Burke and Ernzerhof (PBE, PBE1PBE (PBE0)), and the exchange functional of Tao, Perdew, Staroverov, and Scuseria (TPSSh) with 6-311++G** basis set were employed to examine optical absorption properties. In an extensive comparison between the optical data and DFT benchmark calculations, the BEP functional with 6-311++G** basis set was found to be the most appropriate in describing the electronic absorption spectra. The calculated energy values of lowest unoccupied molecular orbitals (LUMO) were 3.41, 3.19, 3.38 and 3.23 eV for SQD1, SQD2, SQD3, and SQD4, respectively. These values lie above the LUMO energy (-4.26 eV) of the conduction band of TiO₂ nanoparticles indicating possible electron injection from the excited dyes to the conduction band of the TiO₂ in dye-sensitized solar cells (DSSCs). Also, aromaticity computation for these dyes are in good agreement with the data obtained optically and geometrically with SQD4 as the highest aromatic structure. Based on the optimized molecular geometries, relative positions of the frontier orbitals, and the absorption maxima, we propose that these dyes are suitable components of photovoltaic DSSC devices.

A review on recent advances in hierarchically porous metal and metal oxide nanostructures as electrode materials for supercapacitors and non-enzymatic glucose sensors

The remarkable significance of electrode materials in industrial processes, energy, sustainability and diabetes monitoring has captivated scientists to develop advance nanomaterials for the benefit of life across the globe. Here in, the recent developments in nanostructured porous metal and metal oxide composite materials for supercapacitor applications and non-enzymatic glucose sensors (NEGS) has been extensively discussed. The essential and active electrode materials from the research and application perspective has been emphasized in detail. We have also evaluated the worthiness, taxonomical classification, efficiency, specific capacitance and sensitivity of these materials for the aforementioned potential applications. Eventually, we concluded the review by providing the aspect ratio, surface morphology, particle size and specific surface area of these materials that plays an indispensable role for their promising potential applications.

Enhanced electrocatalytic N₂-to-NH₃ fixation by ZrS₂ nanofibers with a sulfur vacancy

Industrially, large-scale NH3 production is achieved by the Haber-Bosch process, which operates under harsh reaction conditions with abundant energy consumption and CO2 emission. Electrochemical N2 reduction is an eco-friendly and energy-saving method for artificial N2 to NH3 fixation under ambient reaction conditions. Herein, we demonstrate that ZrS2 nanofibers with a sulfur vacancy (ZrS2 NF-Vs) behave as an efficient electrocatalyst for ambient N2 reduction to NH3 with excellent selectivity. In 0.1 M HCl, this ZrS2 NF-Vs catalyst attains a large NH3 yield of 30.72 μg h-1 mgcat.-1 and a high faradaic efficiency of 10.33% at -0.35 V and -0.30 V vs. reversible hydrogen electrode, respectively. It also shows high electrochemical and structural stability. The density functional theory calculations reveal that the introduction of Vs facilitates the adsorption and activation of N2 molecules.

Bimetallic NiCoP Nanosheets Array for High‐Performance Urea Electro‐Oxidation and Less Energy‐Intensive Electrolytic Hydrogen Production

Abstract It is highly desired to develop high efficient non‐precious metal catalysts for urea oxidation and energy‐saving electrolytic hydrogen production. In this communication, we report that bimetallic NiCoP nanosheets array on carbon cloth acts as a superb and stable catalyst for urea oxidation reaction (UOR) with the need of potential of 0.455 V to achieve 50 mA cm −2 in 1.0 M KOH and 0.33 M urea. The excellent catalytic activity for hydrogen evolution reaction (HER) enables this electrode as a bifunctional UOR and HER catalyst and its two‐electrode system affords 20 mA cm −2 at a cell voltage of only 1.25 V, 360 mV smaller than that of pure water splitting, with strong long‐term electrochemical stability.

Influence of fuel injection pressure for diesel-waste cooking oil cofuel in a research engine

CCDC 845507: 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.

Isomeric imidazole functionalized bithiophene-based hole transporting materials for stable perovskite solar cells

2,2,7,7-tetrakis(N,N-dip-methoxyphenylamine)-9,9-spirobifluorene (spiro-OMeTAD) is a popular hole-transporting material (HTM) in perovskite solar cells (PSCs), However, it suffers from high-cost and stability issues, which need to be overcome for PSC commercialization. Here, we report isomers of bithiophene-based HTMs functionalized with triarylamine and imidazole for PSCs. The planar 3-ImBT-2D (1) exhibits higher hole mobility than 5-ImBT-2D (2) via modulation of donor-group positions. The PSCs using HTM (1) deliver an excellent power conversion efficiency (PCE) of 21.73% with Li-TFSI doping and 17.79% without dopants. In addition, the Li-TFSI-free device based on 3-ImBT-2D yields a PCE of 21% after HTM surface modification with organic p-dopant dimethylanilinium tetrakis(pentafluorophenyl)borate (DPB). A molecular dynamics study shows that the isomer 3-ImBT-2D (1) folds up after deposition on perovskite films. As a result, the Li-TFSI-free devices exhibit higher stability, retaining 95.9% of the initial PCE after 800 h aging.

Factors Related to Relapse of Congenital Talipes Equinovarus (CTEV) After the Ponseti Method

The only significant factors in the study were the Pirani score and non-compliance of the brace with p < 0.05. There was not any significance in the correction of the deformity by Ponseti between idiopathic and non-idiopathic CTEV based on the number of casts and the Pirani score. The dynamic foot brace can be the solution for the high recurrence rate, yet more studies are needed in the future.

Anthracen-9-ylmethylene-(3,4-dimethylisoxazol-5-yl)amine

The title compound, anthracen-9-ylmethylene-(3,4-dimethylisoxazol-5-yl)amine (3), was synthesized in high yield by reaction of anthracene-9-carbaldehyde and 5-amino-3,4-dimethyl­isoxazole in ethanol. The structure of this new compound was confirmed by elemental analysis, IR, 1H NMR, 13C NMR and GC-MS spectral analysis.

Highly symmetrical, 24-faceted, concave BiVO₄ polyhedron bounded by multiple high-index facets for prominent photocatalytic O₂ evolution under visible light

A highly symmetrical, 24-faceted, concave BiVO4 polyhedron was fabricated, bounded by multiple high-index {012}, {210}, {115}, and {511} facets, exhibiting impressive photocatalytic O2 evolution for water oxidation in the absence of any cocatalysts, more than two orders of magnitude higher than that of the bulk materials. The corresponding apparent quantum yield (AQY) of O2 evolution was measured as high as 30.7% under 420 nm light irradiation, a new record AQY for BiVO4. The high-index facets are not only energetically favorable for water dissociation, but also exhibit an obvious reduction in the overpotential (0.7-1.0 V) for the oxygen evolution reaction.

Synthesis, Modelling, and Anticonvulsant Studies of New Quinazolines Showing Three Highly Active Compounds with Low Toxicity and High Affinity to the GABA-A Receptor

Some novel fluorinated quinazolines (<b>5a</b>-<b>j</b>) were designed and synthesized to be evaluated for their anticonvulsant activity and their neurotoxicity. Structures of all newly synthesized compounds were confirmed by their infrared (IR), mass spectrometry (MS) spectra, ¹H nuclear magnetic resonance (NMR), ¹³C-NMR, and elemental analysis (CHN). The anticonvulsant activity was evaluated by a subcutaneous pentylenetetrazole (scPTZ) test and maximal electroshock (MES)-induced seizure test, while neurotoxicity was evaluated by a rotorod test. The molecular docking was performed for all newly-synthesized compounds to assess their binding affinities to the GABA-A receptor in order to rationalize their anticonvulsant activities in a qualitative way. The data obtained from the molecular modeling was correlated with that obtained from the biological screening. These data showed considerable anticonvulsant activity for all newly-synthesized compounds. Compounds <b>5b</b>, <b>5c</b>, and <b>5d</b> showed the highest binding affinities toward the GABA-A receptor, along with the highest anticonvulsant activities in experimental mice. These compounds also showed low neurotoxicity and low toxicity in the median lethal dose test compared to the reference drugs. A GABA enzymatic assay was performed for these highly active compounds to confirm the obtained results and explain the possible mechanism for anticonvulsant action. The most active compounds might be used as leads for future modification and optimization.