Exploring Rapid Photocatalytic Degradation of Organic Pollutants with Porous CuO Nanosheets: Synthesis, Dye Removal, and Kinetic Studies at Room Temperature

In this work, we report the facile, environmentally friendly, room-temperature (RT) synthesis of porous CuO nanosheets and their application as a photocatalyst to degrade an organic pollutant/food dye using NaBH4 as the reducing agent in an aqueous medium. Ultrahigh-resolution field effect scanning electron microscopy images of CuO displayed a broken nanosheet-like (a length of ∼160 nm, a width of ∼65 nm) morphology, and the lattice strain was estimated to be ∼1.24 × 10-3 using the Williamson-Hall analysis of X-ray diffraction plots. Owing to the strong quantum size confinement effect, CuO nanosheets resulted in an optical energy band gap of ∼1.92 eV, measured using Tauc plots of the ultraviolet-visible (UV-vis) spectrum, resulting in excellent photocatalytic efficiency. The RT synthesized CuO catalyst showed a high Brunauer-Emmet-Teller surface area of 30.88 ± 0.2313 m2/g (a correlation coefficient of 0.99972) with an average Barrett-Joyner-Halenda pore size of ∼20.385 nm. The obtained porous CuO nanosheets exhibited a high crystallinity of 73.5% with a crystallite size of ∼12 nm and was applied as an efficient photocatalyst for degradation of the organic pollutant/food dye, Allura Red AC (AR) dye, as monitored by UV-vis spectrophotometric analysis and evidenced by a color change from red to colorless. From UV-vis spectra, CuO nanosheets exhibited an efficient and ultrafast photocatalytic degradation efficiency of ∼96.99% for the AR dye in an aqueous medium within 6 min at RT. According to the Langmuir-Hinshelwood model, photodegradation reaction kinetics followed a pseudo-first-order reaction with a rate constant of k = 0.524 min-1 and a half-life (t1/2) of 2.5 min for AR dye degradation in the aqueous medium. The CuO nanosheets showed an outstanding recycling ability for AR degradation and would be highly favorable and an efficient catalyst due to the synergistic effect of high adsorption capability and photodegradation of the food dye. © 2021 The Authors. Published by American Chemical Society1

Influence of additives (inorganic/organic) on the clouding behavior of amphiphilic drug solutions: Some thermodynamic studies

AbstractHerein we provide a detailed result about the effect of various additives, viz. inorganic salts, quaternary ammonium bromides (QABs) and amino acids on clouding behavior of amphiphilic drug amitriptyline hydrochloride (AMT). The continuous increase in the cloud point (CP) of drug by increase in inorganic salt concentration and the magnitude of increases rely upon the position of the salts in Hofmeister series and hydrated radii. The QABs also influence continuous increase in the CP, which is illustrated in terms of the alkyl chain length of peculiar QAB. The effect of amino acids on CP of the drug solution is dependent upon the characteristics (acidic, basic, polar or nonpolar) of particular amino acids. The overall behavior of additives has been analyzed and discussed on the basis of electrostatic repulsion or interaction, micellar growth, and mixed micelle formation between the ingredients. In addition to this, thermodynamic parameters are also evaluated

Acetone sensor based on solvothermally prepared ZnO doped with Co3O4 nanorods

This paper describes a reliable and sensitive method for sensing dissolved acetone using doped nanomaterials. Large-scale synthesis of ZnO nanorods (NRs) doped with Co(3)O(4) was accomplished by a solvothermal method at low temperature. The doped NRs were characterized in terms of their morphological, structural, and optical properties by using field-emission scanning electron microscopy coupled with energy-dispersive system, UV-Vis., Fourier transform IR, X-ray diffraction, and Xray photoelectron spectroscopy. The calcinated (at 400 °C) doped NRs are shown to be an attractive semiconductor nanomaterial for detecting acetone in aqueous solution using silver electrodes. The sensor exhibits excellent sensitivity, stability and reproducibility. The calibration plot is linear over a large concentration range (66.8 μM to 0.133 mM), displays high sensitivity (~3.58 μA cm(−2) mM(−1)) and a low detection limit (~14.7 ± 0.2 μM; at SNR of 3). [Figure: see text

Electrocatalytic Behavior and Determination of Amitriptyline Drug with MWCNT@Celllulose Composite Modified Glassy Carbon Electrode

A novel nanocomposite of cellulose based on multiwalled carbon nanotube (MWCNT) was synthesized by a simple solution mixing–evaporation method. The morphology, thermal investigations, electrocatalytic oxidation of amitriptyline were analyzed at multi-walled carbon/cellulose nanocomposite in detail. The amitriptyline (AMT) drug was electrochemically studied in a phosphate buffer at different pH using the MWCNT/cellulose modified glassy carbon electrode (GCE). As per the linear relationship among AMT along with peak current, differential pulse voltammetry technique has been established for their quantitative pharmaceutical’s determination. The oxidation potential shifted negatively compared to GCE, showing that the MWCNT/cellulose modified electrode had an excellent catalytic activity for the AMT oxidation. The anodic peak current varied linear response with AMT’s concentration in the range of 0.5 to 20.0 μM with a LOD of 0.0845 μM and LOQ of 0.282 μM, respectively. The proposed method was effectively put on the determination of AMT in pharmaceutical and urine samples. This novel methodology is presented here as an example of a complete development methodology for the determination of amitriptyline drug and sensor for use in healthcare fields

Polymer Membranes of Zeolitic Imidazole Framework-8 with Sodium Alginate Synthesized from ZIF-8 and Their Application in Light Gas Separation

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

Spectroscopic and Substitution Kinetic Studies of Hexacyanoferrate(II) Complexes byEDTA Catalysed with Mercury(II)

Kinetics and mechanism of substitution of cyanide ion in hexacyanoferrate(II) by EDTA catalysed by mercury(II) has been studied spectrophotometrically at 365 nm in potassium hydrogen phthalate buffer of pH = 5.0 and ionic strength, I = 0.1 M, maintained by (KNO3) at 25 °C. Effect of the pH and concentration of the EDTA, [Fe(CN)4-6] on the rate of reaction has been studied. The kinetics and mechanism of the reaction has been shown through dissociative mechanism. The mechanism of ligand substitution in the complex together with the kinetic data has been shown. The catalytic activity of mercury(II) has also been studied as a function of its concentration. The maximum reaction product was detected at pH = 5 after which a decline in absorption occurs followed by precipitation. It is an inexpensive method to identify and remove the cyanide ion in solution even in very low concentration of the order of 10-4 M

Complexation and oxidation of Flutamide with Fe3+ and 1,10-phenanthroline: Few analytical applications

A simple and sensitive spectrophotometric method has been proposed for the determination of flutamide (FLD). The method is based on its complexation and oxidation of FLD by Fe3+ and 1,10-phenanthroline. Two sets of condition were established. In the first set only FLD reacted with Fe3+ ion, while in the second one FLD was oxidized by Fe3+ in the presence of 1,10-phenanthroline. The complexation and oxidation methods were monitored spectrophotometrically. All variables affecting the development of the color were investigated and the conditions obeying Beer’s law were optimized. Plots of absorbance against concentration in both methods were rectilinear over the ranges 0.5–10 and 0.5–1.5 μg mL−1, with mean recoveries of 99.51 and 99.83 for methods A and B respectively. The limits of detection for procedures 1 and 2 are 0.332 and 0.726 μg mL−1 1, respectively. Both the methods were successfully applied for the determination of the FLD in its dosage form

Sol-Gel Synthesis and Characterization of Highly Selective Poly(N-methyl pyrrole) Stannous(II)Tungstate Nano Composite for Mercury (Hg(II)) Detection

The sol-gel process was used to create a new type of polypyrrole-Stannous(II)tungstate nanocomposite by poly(N-methyl pyrrole (PNMPy) sol in Stannous(II)tungstate gel, produced separately using sodium silicotungstic acid and Tn(II)chloride. Tin(II)tungstate (SnWO3) was made by changing the mixing volume ratios of SnWO3 and with a constant amount of an organic polymer. The composite was characterized by TGA, XRD, FTIR, and SEM measurements. A commercially available glassy carbon electrode (GCE) was modified with PNMPy/nano-Stannous(II)WO3 nanocomposites to create a chemical sensor for selective detection of Hg2+ ions using an effective electrochemical methodology. In the I-V technique, selectively toxic Hg2+ ion was targeted selectively, which shows a rapid reaction toward PNMPy/nano-Stannous(II)WO3/Nafion/GCE sensor. It also demonstrates long-term stability, an ultra-low detection limit, exceptional sensitivity, and excellent reproducibility and repeatability. For 0.1 mM to 1.0 nM aqueous Hg2+ ion solution, a linear calibration plot (r2: 0.9993) was achieved, with a suitable sensitivity value of 2.8241 AM−1 cm−2 and an extraordinarily low detection limit (LOD) of 3.40.1 pM (S/N = 3). As a result, the cationic sensor modified by PNMPy/nano-Stannous(II)WO3/GCE could be a promising electrode

Spectroscopic and Substitution Kinetic Studies of Hexacyanoferrate(II) Complexes byEDTA Catalysed with Mercury(II)

Kinetics and mechanism of substitution of cyanide ion in hexacyanoferrate(II) by EDTA catalysed by mercury(II) has been studied spectrophotometrically at 365 nm in potassium hydrogen phthalate buffer of pH = 5.0 and ionic strength, I = 0.1 M, maintained by (KNO3) at 25 °C. Effect of the pH and concentration of the EDTA, [Fe(CN)4-6] on the rate of reaction has been studied. The kinetics and mechanism of the reaction has been shown through dissociative mechanism. The mechanism of ligand substitution in the complex together with the kinetic data has been shown. The catalytic activity of mercury(II) has also been studied as a function of its concentration. The maximum reaction product was detected at pH = 5 after which a decline in absorption occurs followed by precipitation. It is an inexpensive method to identify and remove the cyanide ion in solution even in very low concentration of the order of 10-4 M