Publications

Here, an important attempt has been employed for the development and applications of Al doped ZnO (Al.ZnO) nanoparticles using hydrothermal method at room conditions. The structural, optical, and chemical properties of the low-dimensional (average diameter, 64.0±10.0 nm) doped Al.ZnO nanoparticles were exemplified using various techniques such as UV/visible, FT-IR, Raman spectroscopy, x-ray powder diffraction (XRD), and Field-emission scanning electron microscopy (FE-SEM) etc. Al.ZnO is an interesting doped nanoparticles for implementation in chemical sensing by reliable I-V method, where hazardous chemical (phenyl hydrazine, PhHyd) is used as a target chemical. The sensor performances are investigated using Al.ZnO nanoparticles embedded onto silver electrodes (AgE, active surface area, 0.0216 cm2), which shows the sensitivity, stability, and reproducibility of the sensor improved significantly. In analytical investigation, the calibration plot is linear over the large concentration range (10.0 µM to 0.05M), where the sensitivity is 1.1432 ± 0.10 µAcm-2mM-1 with a detection limit (LOD) of 1.215 ± 0.02 µM based on signal to noise ratio in short response time. Therefore, it is concluded that the morphologies and the optical features can be implemented to large-scale in transition-metal-doped semiconductor nano-materials as well as efficient chemical sensors.
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Abstract The aim of the presented work was to assess the potential of Medicago polymorpha extract to synthesize silver nanoparticles (AgNPs) as a green method. It was a simple one-step synthesis approach and the product obtained was characterized by UV-visible spectroscopy, Fourier transform infrared (FTIR), powder X-ray diffraction, thermogravimetric analysis, and field-emission scanning electron microscopy (FE-SEM). At room temperature, the optimum time for the completion of the reaction (i.e. the formation colloidal solution) was just 5 min. FE-SEM images showed that AgNPs were predominantly in spheres, whereas FTIR spectrum analysis inferred that gallic acid present in the extract initially reduced silver ions to elemental silver. The carboxylic and hydroxyl groups of biomolecules present in the extract stabilized AgNPs by passivating the surface to prevent aggregation, resulting in uniform distribution. The antibacterial activity of synthesized AgNPs showed effective inhibitory effects against waterborne pathogens, including Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ), at a minimum inhibitory concentration of 10 μg/ml. Membrane permeability and respiration studies were also performed to assess the surface role of the synthesized AgNPs. The prepared AgNPs exhibited excellent antioxidant activity and catalytic reduction of methyl orange with a rate constant of 6.8×10 −3 s −1 .

NH3 is an important chemical with a wide range of applications, but its synthesis mainly relies upon the harsh Haber-Bosch process with huge CO2 emission. Electrochemical N2 reduction offers a carbon-neutral process to convert N2 to NH3 under ambient conditions, but it requires efficient and stable catalysts to drive the N2 reduction reaction. Herein, we report that a sulfur dots-graphene nanohybrid acts as a metal-free electrocatalyst for ambient N2-to-NH3 conversion with excellent selectivity. When operated in 0.5 M LiClO4, this electrocatalyst achieves a large NH3 yield of 28.56 μg h-1 mgcat.-1 and a high Faradaic efficiency of 7.07% at -0.85 V vs. reversible hydrogen electrode. Notably, it also shows good electrochemical stability.

In the crystal structure of the title compound, C(11)H(15)NO(4)S, two independent mol-ecules are present per asymmetric unit; they are dimerized through O-H⋯O hydrogen bonds between their carb-oxy groups to generate R(2) (2)(8) loops. An intra-molecular N-H⋯O link in one of the mol-ecules closes an S(5) ring. The dimers are linked by N-H⋯O and C-H⋯O hydrogen bonds to form a three-dimensional network. The C atoms of the isopropyl group of one of the mol-ecules are disordered over two orientations in a 3:1 ratio.

Bismuth- and antimony-based materials, such as A3M2X9 and AMSX2 (A = cation, M = Bi, Sb, S = sulfur, X = halogen), are promising candidates as the counterpart to lead halide perovskite. However, the large number of different compositions and crystal structures (dimer, perovskite, etc.) has made these materials largely overlooked; thus, an intuitive evaluation strategy is required. Here, we present a comprehensive study of the energy levels (bandgap, valence band maximum, etc.) and optoelectronics (photoconductivity and charge transfer to charge transport material) of the Bi- and Sb-based materials, which include 6 crystal categories with 44 compositions, by using time-resolved microwave conductivity (TRMC). Importantly, we found an efficient hole transfer from the Sb-based materials to the hole transport materials with the inclusion of the thiophene component, leading to an improved power conversion efficiency of 2.91% for Sb2S3-containing SbSI, prepared by a novel one-step method. Our study establishes a key rule for exploring active layer compositions and designing device structures, which would accelerate the evolution of Bi- and Sb-based lead-free solar cells.

In the title compound, C(13)H(9)ClINO(4)S, the dihedral angle between the aromatic rings is 81.04 (17)°. The disposition of the I and Cl atoms attached to the two rings is anti. In the crystal, mol-ecules are connected via O-H⋯O and N-H⋯O hydrogen bonds.

Abstract In this study, by using a co‐precipitation method MoO 3 /CuO/ZnO nanocomposite material was synthesized. Then the prepared material was fully characterized by using XRD (X‐ray diffraction), SEM (scanning electron microscopy), EDS (energy dispersive x‐ray spectroscopy), CV (cyclic voltammetry), and EIS (Electrochemical Impedance Spectroscopy). Zeta potential and hydrodynamic size were measured using a Zetasizer in PBS buffer. By using Scherrer's formula from XRD, particle size was determined which was around 26.5 nm. For the promising chemical sensor development, MoO 3 /CuO/ZnO nanocomposite material was fabricated onto a glassy carbon electrode (GCE) to provide a sensor probe with a fast response towards the selective hydrazine (HZ) toxin in phosphate buffer phase. The fabricated sensor probe is exhibited good sensitivity and long‐term stability as well as enhanced electrochemical performances. A calibration plot was found linear in the range of 0.2 nM to 2.0 mM (linear dynamic range, LDR) in presence of aqueous HZ solutions with highest sensitivity value and lower limit of detection and good limit of quantification (LOQ). This approach is promising as an efficient technique in developing a highly effective sensor probe with ternary metal oxides for detecting environmental pollutants on a broad scale.

The potential of nanocomposite membranes (NCMs) prepared by the sodium alginate polymer and embedded with synthesized zeolitic imidazole framework-8 (ZIF-8) as fillers having microporous structure in the application of separation of gaseous mixture generated by the process of methane reforming was assessed. ZIF-8 crystals were created through hydrothermal synthesis, with sizes varying from 50 to 70 nm. NCMs were prepared with a 15% filler loading, i.e., synthesized ZIF-8. NCMs (ZIF-8) having H2 permeability of 28 Barrer and H2/CH4 selectivity of 125 outperformed neat polymer membranes in terms of separation performance at ambient temperature and 4 kg/cm2 pressure. The purity of H2 increased to as high as 95% among the measured values. The NCMs did not, however, outperform a neat polymer membrane in terms of their ability to separate mixtures of gases. Moreover, the combination of ZIF-8 as a filler with sodium alginate was new and had not been reported previously. As a result, it is worthwhile to investigate.

The influence of polymer, polyvinylpyrrolidone (PVP) on spectral properties of anionic azo dye, reactive yellow (RY) was investigated by UV–Vis spectroscopy in the temperature range of 298–313 K. The change in λmax and absorbance indicated the presence of interaction between anionic dyes and polymer. The binding constant (Kb) of complexation was determined from the Benesi–Hildebrand plot. The Kb value increased with increasing dye concentrations and decreased with the rise of the temperature. The values of ∆G° for RY–PVP complexation were found to be negative and these negative values reduce with the enhancement of temperature which indicates that the binding process is more spontaneous at lower temperature. The negative values of ΔS° and negative values of ΔH° refer a process which is always enthalpy dominated. Kb values showed significant change with the change of pH. The Kb value enhances with the rise of the carbon chain length of the alcohol and reduces with increasing percentages of alcohol. The Kb value decreases at higher electrolyte concentrations and also with the increase of the size of the anion of the electrolyte. The removal of dye from the waste water by the interaction of dye with polymer in the presence of surfactant and salt of higher concentration has also been studied.