Functionalization of UiO-66-NH2 by In-Situ Incorporation of Nanomaterials to Enhance Photocatalytic Efficiency Towards Oxygen Evolution Reaction

The catalysts for oxygen evolution reaction (OER) are required to generate clean energy. Herein, one-step solvothermal synthesis and modification of amino functionalized Zr-based metal organic framework, UiO-66-NH₂, is reported. The catalytic efficiency of UiO-66-NH₂ towards OER is improved by incorporating the cerium-based nanocomposite such as Ce₂O₃, TiO₂/Ce₂O₃ and CoO/Ce₂O₃. The synthesized samples are characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray, diffraction, and ultraviolet–visible spectroscopy. The synthesized materials are coated on nickel foam for investigating the catalytic activity towards OER by cyclic voltammetry and linear sweep voltammetry. Amongst, CoO/Ce₂O₃@UiO-66-NH₂/NF exhibits excellent OER-catalytic activity and delivers 10 mA cm^?2 current density at just 228 mV overpotential which is superior to many previously reported OER catalysts and its comparative products. To understand kinetics, Tafel slope is derived from LSV curve and is just 92 mV dec^?1.

Graphical Abstract

     

Nanocomposites of transition metals tungstate for potential applications in magnetic and microwave devices

Ni_2-xCo_x(WO₄)₂ and Ni_2-xMn_x(WO₄)₂ (x?=?0.0, 0.50, 1.0, 1.50 and 2.0) nanocomposites have been synthesized by facile hydrothermal method. The synthesized samples have been characterized by powder XRD and Scanning Electron Microscopy to analyze the structure and morphology. Structural analysis has revealed the single phase formation with wolframite monoclinic system for NiWO₄ samples. The calculated crystallite size ranges from 6 to 40 nm for the nanocomposites. Magnetic and dielectric parameters have also been studied. Magnetic susceptibility measurements of each sample have been carried out at room temperature (312 K) by using Sherwood magnetometer. A decrease in susceptibility values has been observed by increase in the concentration of manganese or cobalt in nickel tungstate leading to antiferromagnetic behavior. Dielectric measurements in the frequency range of 6 kHz to 1 MHz have been calculated. The analysis showed that dielectric parameters decrease with increase in frequency.     

Accumulation of fluorescent non-cationic probes in mitochondria of cultured cells: observations,a proposed mechanism,and some implications

Cultured rat fibroblasts were exposed to millimolar concentrations of forty-four non-cationic fluorescent probes, of very varied physico-chemical properties. Mitochondrial staining occurred with nineteen of these probes, nine of which were nominally anionic and ten nominally non-ionic. All nineteen were in fact lipophilic weak acids. Using structural parameters these could be specified numerically as follows: electric charge ≤ 0; log P(less-ionized form) < 0; and pKa ～ 7. In addition to these structural variables, dye concentration and the time of exposure of cells to probes were significant factors for the staining of mitochondria. Accumulation of these compounds can be understood in terms of ion-trapping of hydrophilic salts of lipophilic weak acids, due to the internal pH of respiring mitochondria being higher than the cytosolic pH. As a case example of the application of this approach, the mode of action of many inhibitors of mitochondrial anabolism is discussed in terms of the mechanisms introduced here.     

Comparative Simulation of GIS-Based Rainwater Management Solutions

Rain Water Harvesting (RWH) as a solution for sustainable rainwater management is the focus of this research. To locate the potential sites for RWH, multi-criteria analysis following analytical hierarchy process using land-use/landcover, slope, drainage density, and runoff depth has been performed. By introducing continuous soil moisture accounting procedure in the globally used SCS-CN method, discrepancies in computed runoff values have been assessed. To appraise the usefulness of revised Soil Moisture Accounting (SMA) -enhanced SCS-CN models, a number of modifications have been compared. The models’ performance has been evaluated using R², Root Mean Square Error (RMSE), Nash Sutcliffe Efficiency (NSE), Percent BIAS (PBIAS) statistical indicators, and Rank Grading System (RGS) and the best has been selected to calculate the runoff depth for RWH potential zones. The resultant suitability map classifies Gurriala catchment into three suitability zones. 33.8% of the total area has been found as least suitable, comprised mainly of forest, residential land, and water bodies, while 46.8% and 19.4% of the area is recognized as moderately suitable and high suitable respectively. Selected suitable sites have been further classified into suitability zones for enhanced RWH structures and runoff volume contributed by each RWH structure has been computed. The total runoff potential of the area is 22.47 MCM that is enough to fulfill the water demands of suburban areas as a most inexpensive solution.

     

Anti-fog System for High Speed Vehicles Using WI-FI

Wireless Personal Communications - Smog is considered as a serious worldwide problem especially in Asian countries resulting sometimes in fatal injuries. Wireless communication can play a vital...     

Investigative evaluation of Cassia absus for antibacterial capacity and biomimetic synthesis of silver nanoparticles

Cassia absus is used for medicinal purposes for a long time all over the world. In this study, the authors report the antimicrobial potential of C. absus extracts obtained with different solvents. The extract(s) obtained with ethyl acetate yielded the best antibacterial effects because of a rich supply of oxalates and alkaloids in it. The same extract was also exploited for reducing Ag⁺ ions (to metallic Ag⁰) for the synthesis of nanoparticles. Electron microscopy revealed that the silver nanoparticles were ∼18–25 nm in diameter. The Fourier‐transform infrared evaluation pointed towards the fact that flavonoids present in the plant extract were acting as reductants while amino groups were the bound stabilisation agents to the synthesised nanoparticles limiting the diameter to a certain threshold and avoiding aggregation naturally. A comparative antibacterial assay of C. absus versus Ag nanoparticles showed that the nanoparticles as well as organic (ethyl acetate) extract of the plant checked the growth of selected (MDR) superbugs. However, the biosynthesised Ag nanoparticles returned better antibacterial efficacies than ethyl acetate extract.Inspec keywords: biomimetics, nanomedicine, nanoparticles, nanofabrication, reduction (chemical), microorganisms, silver, antibacterial activity, Fourier transform infrared spectra, biomedical materials, electron microscopyOther keywords: antibacterial capacity, biomimetic synthesis, silver nanoparticles, antimicrobial potential, ethyl acetate, oxalates, alkaloids, electron microscopy, Fourier‐transform infrared evaluation, antibacterial efficacies, antibacterial assay, organic extract, Cassia absus, flavonoids, Ag     

Performance Analysis of Location Based Smart Catastrophe Monitoring System Using WSN

Wireless Personal Communications - Sudden accident in factories causes huge damage to human life and property which is a serious problem. The fire incident of Baldia Town factory Karachi, Pakistan...