Synthesis of Zinc Oxide Nanorods from Zinc Borate Precursor and Characterization of Supercapacitor Properties.

The synthesis of zinc oxide (ZnO) was accomplished from zinc borate (Zn3B2O6) minerals to be used as electrodes in supercapacitor applications. The concentrations of obtained zinc (Zn) metal after treatment with hydrochloric acid (HCl) were determined by atomic absorption spectroscopy (AAS). Direct synthesis of ZnO on a nickel (Ni) foam surface was conducted by employing the hydrothermal technique using a solution with the highest Zn content. The results showed the successful synthesis of ZnO nanorods on the surface of Ni foam with an average wall size of approximately 358 nm. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements revealed that the synthesized electrode exhibited battery-type charge storage characteristics, reaching a maximum specific capacitance of approximately 867 mF·cm-² at a current density of 2 mA·cm-². Additionally, the energy and power densities of the electrode at a current density of 2 mA·cm-² were calculated as 19.3 mWh·cm-² and 200 mW·cm-², respectively. These results exhibited promising performance of the single-component electrode, outperforming the existing counterparts reported in the literature.

Investigation of adsorption performance of calcium oxide particles upon various treatments.

This study describes the improvements of adsorption capacities for raw calcium oxide (CaO) particles subjected to ultrasonication, activation with nitric acid and thermal treatments. The influence of acids and bases on CaO particle surface was assessed with respect to several variables including treatment methods, adsorption contact times, particle size and specific surface area characteristics, concentration and temperature along with various thermodynamic parameters. Structural analyses and physical characteristics of CaO particles were evaluated using FT-IR and SEM methods. SEM micrographs of samples revealed uniform distributions of CaO particles of average diameter 0.5-2.0 µm. The CaO surfaces showed CH3COOH as having the greatest amounts of adsorbate and modeling of the experimental adsorption isotherm data agreed well with the Freundlich adsorption isotherm. Enhancements in adsorption performance of untreated CaO particles were noted with the ultrasonication, activation with HNO3 and thermal treatment processes. The Langmuir-type adsorption demonstrated that single layer adsorption capacities of adsorbate CH3COOH at 25 oC on sonicated CaO (386.6 mg/g), with nitric acid and thermal activation (354.9 and 320.8 mg/g, respectively) were greater than that of the unsonicated CaO (296.3 mg/g) particles. Adsorption spontaneities of the processes were confirmed by the decreases in adsorption free energy values, ΔGads0, changing from -16.1 to -17.1 kJ mol-1 with temperature range 283-338 K.

Evolution of Microstructure, Mechanical Properties, and Corrosion Resistance of Mg-2.2Gd-2.2Zn-0.2Ca (wt%) Alloy by Extrusion at Various Temperatures.

The current investigation involved casting the Mg-2.2Gd-2.2Zn-0.2Ca (wt%) alloy (GZX220) through permanent mold casting, followed by homogenization at 400 °C for 24 h and extrusion at 250 °C, 300 °C, 350 °C, and 400 °C. Microstructure investigations revealed that α-Mg, Mg-Gd, and Mg-Gd-Zn intermetallic phases were present in the as-cast alloy. Following the homogenization treatment, a majority of these intermetallic particles underwent partial dissolution into the matrix phase. α-Mg grains exhibited a considerable refinement by extrusion due to dynamic recrystallization (DRX). At low extrusion temperatures, higher basal texture intensities were observed. The mechanical properties were remarkably enhanced after the extrusion process. However, a consistent decline in strength was observed with the rise in extrusion temperature. The corrosion performance of the as-cast GZX220 alloy was reduced by homogenization because of the lack of corrosion barrier effect of secondary phases. A significant enhancement of corrosion resistance was achieved by the extrusion process.

Sustainable Cauliflower-Patterned CuFe2O4 Electrode Production from Chalcopyrite for Supercapacitor Applications.

The primary purpose of this study was to produce an ore-based high-capacity supercapacitor electrode. For this, chalcopyrite ore was first leached with nitric acid, and then metal oxide synthesis was carried out immediately on nickel foam using a hydrothermal technique from the solution. Cauliflower-patterned CuFe2O4 with a wall thickness of about 23 nm was synthesized on the Ni foam surface, characterized by XRD, FTIR, XPS, SEM, and TEM investigations. The produced electrode also displayed a feature of a battery-like charge storage mechanism with a specific capacity of 525 mF cm-2 at 2 mA cm-2 current density, energy of 8.9 mWh cm-2, and a power density of 233 mW cm-2. Additionally, even after 1350 cycles, this electrode still performed at 109% of its original capacity. The performance of this finding is 255% higher than that of the CuFe2O4 in our earlier investigation; despite being pure, it performs far better than some of its equivalents in the literature. Obtaining such performance from an electrode made from ore indicates that the use of ore has a lot of potential for supercapacitor production and property improvement.

Synthesis, characterization, in vitro cytotoxicity and antimicrobial investigation and evaluation of physicochemical properties of novel 4-(2-methylacetamide)benzenesulfonamide derivatives.

In this study, several sulfonamide derivatives, 4-(2-methylacetylamino)benzenesulfonamides were synthesized. Chemical structures of the derivatives were characterized by 1H NMR, 13C NMR, LC-MS-MS, UV-Vis, FTIR, photoluminescence and elemental analysis. Sulfanilamide was reacted with 2-bromopropionyl bromide, in the presence of pyridine, to form bromo-substituted sulfonamide key intermediates, which were subsequently treated with secondary amines to obtain novel sulfonamide derivatives. All the synthesized compounds were evaluated for in vitro antimicrobial activities and cytotoxicity. Increases in ring size, and rings bearing a nitrogen heteroatom led to improvements in antimicrobial activities. As the presence of CA IX and CA XII enzymes have been implicated in some cancerous tumors, the studies presented herein focuses on targeting these enzymes. It was found that the synthesized derivatives had in vitro anti-cancer properties, where compounds (3-6) were found to be active against all cancerous cells, and no cytotoxic effects on normal cells were observed.

A new Salen-type azo-azomethine ligand and its Ni(II), Cu(II) and Zn(II) complexes: Synthesis, spectral characterization, crystal structure and photoluminescence studies.

A novel Salen-type azo-azomethine ligand H2agen, 2,2'-{ethane-1,2-diylbis[nitrilomethylylidene]}bis{4-[ethylphenyldiazenyl]phenol}, formed by the 1:2M condensation of ethane-1,2-diamine with 5-[(4-ethylphenyl)diazenyl]-2-hydroxybenzaldehyde and its nickel(II), copper(II), and zinc(II) complexes were synthesized and characterized by the spectroscopic and analytical methods. The UV-vis spectra of the ligand were investigated in three organic solvents (DMSO, DMF and CHCl3). The ligand shows two absorption bands assigned to π-π(∗) and n-π(∗) transitions in the solvents used. Cu(II), and Ni(II) are tetra-coordinate binding to two phenolic oxygens and two imine nitrogens in approximate square planar geometry. Zn(II) also coordinates using the same sites like other metals but gave tetragonal configuration. Molecular structure of the Cu(II) complex [Cu(agen)] was determined by single crystal X-ray diffraction study. The X-ray data revealed that crystallographic imposed symmetry was absent for the complex molecule. In the structure, the Cu(II) ion is coordinated to two phenolate oxygen atoms and two imine nitrogen atoms of the azo-azomethine ligand with approximate square planar geometry. The ligand H2agen and its metal complexes exhibit strong blue emissions with irradiation. Fluorescence quantum yields and excited-state lifetimes for the ligand and its complexes were obtained. The H2agen ligand had a 35% quantum yield and a 3.27 ns excited-state lifetime. Complexation with metal ions caused reductions in intensities and quantum yields.

Adsorption of acids and bases from aqueous solutions onto silicon dioxide particles.

The adsorption of acids and bases onto the surface of silicon dioxide (SiO(2)) particles was systematically studied as a function of several variables, including activation conditions, contact time, specific surface area, particle size, concentration and temperature. The physical properties of SiO(2) particles were investigated, where characterizations were carried out by FT-IR spectroscopy, and morphology was examined by scanning electron microscopy (SEM). The SEM of samples showed good dispersion and uniform SiO(2) particles with an average diameter of about 1-1.5 microm. The adsorption results revealed that SiO(2) surfaces possessed effective interactions with acids and bases, and greatest adsorption capacity was achieved with NaOH, where the best fit isotherm model was the Freundlich adsorption model. The adsorption properties of raw SiO(2) particles were further improved by ultrasonication. Langmuir monolayer adsorption capacity of NaOH adsorbate at 25 degrees C on sonicated SiO(2) (182.6 mg/g) was found to be greater than that of the unsonicated SiO(2) (154.3mg/g). The spontaneity of the adsorption process was established by decreases in DeltaG(ads)(0), which varied from -10.5 to -13.6 kJ mol(-1), in the temperature range 283-338K.