Scanning Electron Microscopy-energy Dispersive X-ray Research Articles

Synthesis and crystal structure of Ba2Y0.87(1)Mn1.71(1)Te5.

We report the structural characterization of a new quaternary telluride, Ba2Y0.87(1)Mn1.71(1)Te5, which was synthesized by the direct reaction of the elements inside a vacuum-sealed fused-silica tube. The quaternary phase is the first member of the Ba-M-Mn-Te system (M= Sc and Y). The composition and structure of the phase were elucidated using SEM-EDX (scanning electron microscopy-energy dispersive X-ray spectrometry) and single-crystal X-ray diffraction (SCXRD) studies. The title phase is nonstoichiometric and crystallizes in the monoclinic system (space group C2/m) having the refined unit-cell parameters a= 15.1466 (8), b= 4.5782 (3), c= 10.6060 (7) Å and β= 116.956 (2)°, with two formula units (Z= 2). The pseudo-two-dimensional crystal structure of Ba2Y0.87(1)Mn1.71(1)Te5 consists of distorted YTe6 octahedra and MnTe4 tetrahedra as the building blocks of the structure. The YTe6 octahedra are arranged to form infinite one-dimensional chains by sharing edges along the [010] direction. These chains are further connected to the MnTe4 tetrahedra along the c axis to create layered two-dimensional polyanionic [Y0.87(1)Mn1.71(1)Te5]4- units. The stuffing of Ba2+ cations in between the layers of [Y0.87(1)Mn1.71(1)Te5]4- anions brings the charge neutrality of the structure. Each Ba atom in the structure sits at the centre of a distorted monocapped trigonal prism-like polyhedron of seven Te atoms.

Green synthesis approach using deep eutectic solvents to enhance the surface functional groups on porous carbon for CO2 capture

This study explores the potential of green solvents using amino acids-based deep eutectic solvents to alter surface functionality of activated carbon thus enhancing the carbon dioxide (CO2) adsorption capacity. Green solvent is prepared by mixing an amino acid (L-Arginine) with ethylene glycol to form amino acid-based deep eutectic solvents. Amino acid-based deep eutectic solvents were used to modify the surface functionalities of activated carbon derived from palm shell waste. The change in surface functional groups and surface morphology of the modified activated carbon samples were characterized by Fourier-transform infrared spectroscopy and Scanning electron microscopy-energy dispersive X-ray analysis. Then, CO2 removal performance was performed using a packed-bed CO2 adsorption reactor to evaluate CO2 breakthrough time and adsorption capacity. CO2 adsorption experiments were measured at a certain temperature (25–45°C), at a fixed feed flow rate and CO2 concentration of 200 mL/min and 15%. It was observed that modified activated carbon showed the highest breakthrough time (15.2 min) compared to raw palm shell (5.2 min) at an adsorption temperature of 25°C. CO2 breakthrough times significantly decreased with increasing adsorption temperature because of physical adsorption.

Extending the Lifetime of Frying Oil through Optimization of Fryer Cleaning.

With increases in consumer demand for fried foods in Japan over the last several decades, the consumption of frying oil has also steadily increased. Fryers used in restaurants to cook large quantities of food are typically cleaned using neutral kitchen detergents at the end of the day after removing the oil from the tank. However, significant amounts of debris can remain in the fryer after cleaning, possibly accelerating oil deterioration and thus reducing the quality of the fried foods. In this study, debris obtained from fryer tanks used in actual restaurants was assessed using scanning electron microscopy-energy dispersive X-ray spectroscopy together with Fourier transform infrared spectroscopy, and were determined to comprise polymerized oil and carbonized organic matter. Experiments using artificially prepared debris confirmed that these materials increased the acid value (AV) of frying oil. Trials in two restaurants serving similar amounts of fried chicken, French fries and doughnuts examined the effects of cleaning the fryer with either an alkaline detergent or a neutral kitchen detergent on debris removal and oil life. The alkaline detergent was found to completely remove debris while the neutral detergent left significant amounts of debris. After cleaning, the fryers were operated with new oil as usual and the deterioration of this oil was monitored by assessing the color difference, AV, carbonyl value and peroxide value. These indices increased 1.3 to 2.0 times faster in the case that the neutral kitchen detergent was used, suggesting that cleaning fryer tanks with an alkaline detergent could contribute to extending the lifetime of frying oil, reducing food losses and thus achieving sustainable development goals.

Hydrodeoxygenation of anisole over SBA-15-supported Ni, Pd, and Pt mono- and bimetallic catalysts: effect of the metal's nature on catalytic activity and selectivity.

Monometallic Ni, Pd and Pt and bimetallic catalysts formed by combinations of the above metals supported on SBA-15 silica were synthesized, characterized and tested in the hydrodeoxygenation reaction of anisole. The objective of the work was to detect the effect of the nature of metals on the activity of the catalysts at different steps of anisole hydrodeoxygenation: hydrogenation of the aromatic ring of anisole and C-O bond cleavage in the intermediate cyclohexyl methyl ether. The support and the catalysts were characterized by N2 physisorption, X-ray diffraction, UV-vis diffuse reflectance spectroscopy, temperature-programmed reduction, scanning electron microscopy-energy dispersive X-ray spectroscopy, transmission electron microscopy and HAADF-STEM. The catalytic activity tests were carried out in a batch reactor at 280 °C and 7.3 MPa pressure. The activity results show that the NiPd/SBA-15 catalyst had the greatest ability for hydrogenation of the aromatic ring of anisole, while its NiPt/SBA-15 analog resulted in better activity for C-O bond hydrogenolysis. The bimetallic NiPt/SBA-15 catalyst showed the best catalytic performance in the HDO of anisole ascribed to the formation of a Ni-Pt alloy. On the other hand, the combination of Pd and Pt metals in the PdPt/SBA-15 catalyst resulted in the formation of bimetallic particles with Pd-rich and Pt-rich domains, showing high selectivity for the formation of the cyclohexyl methyl ether, which can be useful for the hydrogenation of aromatic rings in O-containing reactants with the formation of saturated O-containing products. According to the characterization results (HAADF-STEM), the different catalytic behavior of NiPd/SBA-15, NiPt/SBA-15, and PdPt/SBA-15 catalysts could be attributed to different characteristics of the bimetallic active phases in them.

Nickel(II) complexes with 14-membered bis-thiosemicarbazide and bis-isothiosemicarbazide ligands: synthesis, characterization and catalysis of oxygen evolution reaction.

Design and development of novel, low-cost and efficient electrocatalysts for oxygen evolution reaction (OER) in alkaline media is crucial for lowering the reaction overpotential and thus decreasing the energy input during the water electrolysis process. Herein, we present the synthesis of new 14-membered bis-thiosemicarbazide and bis-isothiosemicarbazide macrocycles and their nickel(II) complexes characterized by spectroscopic techniques (1H and 13C NMR, IR, UV-vis), electrospray ionization mass spectrometry, single crystal X-ray diffraction, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and cyclic voltammetry. Finally, the activity of nickel(II) complexes towards OER is reported. NiIILSEt delivered a current density of 10 mA cm-2 at the lowest overpotential of 350 mV with the lowest Tafel slope of 93 mV dec-1. The high performance of NiIILSEt might be attributed to its high surface area and thus abundant active sites with the observed low charge-transfer resistance enabling the effective current flow through the electrocatalyst. Square-planar coordination geometry and increment in Ni oxidation state are believed to favor its OER performance. Beside high activity towards OER, NiIILSEt demonstrated excellent long-term stability with continuous operation, advocating its possible application in commercial systems.

A rapid one-step synthesis of silver and copper coordinated chlorine functionalized fullerene nanoparticles with enhanced antibacterial activity.

Nanoparticle modification demonstrates a remarkable synergetic effect in combating bacteria, particularly resistant bacteria, enhancing their efficacy by simultaneously targeting multiple cellular pathways. This approach positions them as a potent solution against the growing challenge of antimicrobial-resistant (AMR) strains. This research presents an investigation into the synthesis, characterization, and antibacterial evaluation of silver-coordinated chloro-fullerenes nanoparticles (Ag-C60-Cl) and copper-coordinated chloro-fullerenes nanoparticles (Cu-C60-Cl). Utilizing an innovative, rapid one-step synthesis approach, the nanoparticles were rigorously characterized using X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometer (SEM-EDS), High-Resolution Transmission Electron Microscopy (HR-TEM), Fourier-Transform Infrared Spectroscopy (FTIR), and Raman spectroscopy. In conjunction with the analytical techniques, a computational approach was utilized to corroborate the findings from Raman spectroscopy as well as the surface potential of these nanoparticles. Moreover, the antibacterial activities of the synthesized nanoparticles were assessed against Escherichia coli (E. coli) and Methicillin-Resistant Staphylococcus aureus (MRSA). These findings demonstrated that the synthesized Ag-C60-Cl and Cu-C60-Cl nanoparticles exhibited minimum inhibitory concentrations (MIC) of 3.9 μg mL-1 and 125 μg mL-1, respectively. Reactive oxygen species (ROS) quantification, catalase assay, and efflux pump inhibition results revealed promising broad-spectrum antibacterial effects.

Search for Alternative Raw Materials for Pellet Production – a Preliminary Study

Abstract A preliminary study for a selection of local alternative raw materials and their possible applicability in pellet production was done. 13 alternative biomass sources available in Riga, Latvia were tested: pine mix pellets (PMP); pellets of a mix of wood shavings, synthetic and textile waste (SSK); hogweed (Heracleum sosnowsky, HW); the full plant of Solidago canadensis L. (SC); the full plant of Solidago canadensis L. outgrown (SCO); mowed grass from the municipality (MGM); mowed grass from the garden (MGG); chamomile full plant without stems (Matricaria chamomilla, CF); hemp without roots (Cannabis sativa L., HWR); hemp stems (Cannabis sativa L., HS); hemp leaves with seeds (Cannabis sativa L., HLS); spent grain (SG); damaged spent grain (DSG). The determined quality parameters were the moisture content, the ash content, the calorific value and ash melting temperature. A comparison was made with the quality parameters defined in ENplus certification for B-class wood pellets in requirements for producers. Additional determination of chemical composition using XRD (X-ray diffraction) and SEM-EDX (scanning electron microscopy – energy dispersive X-ray spectroscopy) for the ash of two selected materials – SC and HLS – was performed to determine possible issues. The main issues highlighted by the results is the high ash content of alternative materials, up to 11.27 wt% while it is below 2.00 wt% for B-class wood pellets, and the low ash deformation temperature, below 1100 °C for 5 of the studied materials. Considering this, a calculation was made to determine the optimal proportion of alternative material to be used in a raw material mix for pellets to achieve a quality corresponding to B-class wood pellets. The aim of the study is to evaluate a set of locally available biomass materials, determining the values of their characteristic parameters, thus identifying alternative resources to wood for the production of pellets. This kind of promoting the diversification of energy resources, increasing energy independence and strengthening energy security.

Investigating the CoS2 Mass Fraction Enhancing Performance Supercapacitor for Medium Low Consumption

Supercapacitor are one of the most environmentally friendly electrical energy storage devices. Improvement of supercapacitor performance continues to be carried out by combining active materials and transition metal oxides/hydroxides. In this study, a composite electrode material based on activated carbon with a mass percent variation of CoS2 has been successfully carried out. The composition of Ni(OH)2 - CoS2 /Graphene Nanosheet//Carbon electrode consists of 10, 15, and 20% CoS2 . The electrodes were then characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope - Energy Dispersive X-ray (SEM-EDX). The research was continued by fabricating a symmetric coin cell. Supercapacitor device performance was characterized using Cyclic Voltammetry (CV), Charge-Discharge (CD) and Electrochemical Impedance Spectroscopy (EIS). The morphology of activated carbon shows porous chunks that are beneficial in the electrolyte ion adsorption process. While CoS2 and Ni(OH)2 materials indicated in bulk form. Characterization results show the most optimum sample is in the 15% CoS2 sample with EIS characterization showing the smallest equivalent series resistance (ESR) of 0.81 Ω. CD characterization results were able to have specific capacitance, energy density and power density of 58.25 Fg-1, 1.59 Wh/kg, and 70.49 W/kg respectively and were able to survive up to 88.84% after 1000 test.

Effect of Vaporized Hydrogen Peroxide and Nitrogen Dioxide Sterilization on Nitinol.

Background: Nitinol is used as the structural framework in numerous types of medical devices (e.g., guidewires, transcatheters, stents). The desire to understand the material compatibility of nitinol with vaporized hydrogen peroxide (VH2O2) and nitrogen dioxide (NO2) sterilization is increasing in healthcare technology. As a result of increased regulatory pressure and capacity limitations related to ethylene oxide (EO) sterilization, the industry is seeking alternative, sustainable sterilization options. Objective: This study sought to characterize the corrosion resistance of nitinol metal alloy wire when exposed to varying levels of VH2O2 and NO2 sterilization. Methods: Scanning electron microscopy (SEM) imaging and energy-dispersive X-ray spectroscopy (EDS) scans were performed to understand the effects of VH2O2 and NO2 sterilization treatments on the surface morphology and chemical composition of nitinol. Results: From the SEM-EDS results, no notable difference was observed when comparing VH2O2 and NO2 test samples with nonsterile control samples. In addition, cyclic potentiodynamic polarization measurements were performed per ASTM F2129-19a to determine corrosion susceptibility. No considerable changes were detected in the electrochemical potential after VH2O2 and NO2 sterilization treatments, when compared with the nonsterile control samples. Conclusion: SEM-EDS and corrosion test results indicated no considerable changes in the surface properties or electrochemical potential of the sterilized samples compared with the nonsterilized control samples. Therefore, nitinol metal showed promising results for compatibility with VH2O2 and NO2 sterilization.

Investigation of Antibacterial and Antifungal Efficacy of Zinc and Silver Nanoparticles Synthesized from Nasturtium officinale

Nanoparticles are nano-sized materials that can be widely used in fields such as medicine, pharmacology, and industry. The use of natural and easily available materials in nanoparticle synthesis is preferred because it is economical. Plants are extremely suitable for the synthesis of nanoparticles due to their natural and easy availability and the large number of components they contain with different properties. For this purpose, silver nanoparticles and zinc nanoparticles (AgNPs and ZnNPs), two different nanoparticles were synthesized from an edible plant, watercress (Nasturtium officinale). SEM (Scanning electron microscopy), SEM-EDX (Scanning electron microscopy-Energy dispersive X-ray), UV-VIS spectroscopy, XRD (X-ray crystallography), and FTIR (Fourier Transform Infrared Spectrophotometer) analyses of these nanoparticles were performed. In addition, the antimicrobial effects of these synthesized nanoparticles were determined by the disk diffusion method. As a result, nanoparticles obtained from Nasturtium officinale were effective on gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa), gram-positive bacteria (Staphylococcus aureus, Streptococcus pyogenes), and fungi (Candida albicans). In particular, AgNPs with broad-spectrum antimicrobial activity were obtained from the watercress. While ZnNPs showed inhibition effects of 49% on K. pneumoniae, 51% on S. aureus, and 62% on C. albicans, AgNPs showed inhibition effects of 93% on P. aeruginosa, 87% on S. aureus, 81% on E. coli, 80% on C. albicans, 72% on K. pneumoniae, and 56% on S. pyogenes. Thus, it has been shown that Nasturtium officinale can be used effectively in the production of new biotechnological products, especially with antimicrobial properties.

The adsorption of naproxen on adsorbents obtained from pepper stalk extract by green synthesis

Abstract This study presented the adsorption of naproxen on adsorbents filled with Cu, Fe, and Cu/Fe nanoparticles (NPs) obtained by the green synthesis method from pepper stem waste. The resulting adsorbents were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, and thermal gravimetric-differential thermal analysis. The amount of naproxen not adsorbed in the solution was determined from the cyclic voltammetry method, which is one of the electrochemical methods. The equation of the calibration curve used in the conversion of current to concentration and the R 2 value were y = 2.6165 x − 288.22 y=2.6165x-288.22 and 0.999, respectively. While the adsorption with the BS-extract was 3.3%, it was 46.142% for Cu-NP, 92 mg/g, and 57.622% for Fe-NP. With 116.0 mg/g Cu/Fe-NP, 82.406% and 165.0 mg/g capacity were reached. In the isotherm calculations, since the R 2 values for each adsorbent were in the range of 0.998–0.997, it was determined that the Freundlich and Halsey isotherms were compatible. Accordingly, under these conditions, Naproxen adsorption was multilayered and the adsorbent surface had a heterogeneous structure. Graphs drawn from the kinetic data showed that the adsorption obeyed the second-order kinetics. The R 2 value of the kinetic curves was 1 for all adsorbents. Thermodynamic data were determined by Van’t Hoff curves with R 2 values in the range of 0.998–0.996. The enthalpy value for Cu/Fe-NP was calculated to be 31.854 kJ/mol, the entropy value was 0.1993 kJ/mol-K, and the free energy was −27.5374 kJ/mol. These values were 34.605 kJ/mol, 0.272 kJ/mol-K, and −46.451 kJ/mol for Fe-NP, respectively; and 19.79 kJ/mol, 0.247 kJ/mol-K, and −54.3226 kJ/mol for Cu-NP. While all NPs (except Cu-NP) had a high recovery percentage in three cycles, this decreased to 80% at pH 10. For Cu-NP, the recovery percentage decreased at pH 8.5 and 7, but surprisingly it increased at pH 10. As a result, it can be inferred that NPs play a good role in adsorbent development, and Fe and Cu NP-doped BS adsorbents have a better effect on naproxen adsorption and have been evaluated as adsorbents suitable for use several times.

Modification of Polyethylene Glycol and Citric Acid on Palm Fiber Waste Nanofibers on the Adsorption of Violet Crystal Dyes

<p>This study developed nanofibers derived from sugar palm fiber waste, incorporating citric acid and polyethylene glycol (PEG) modifications to adsorb crystal violet (CV) dye. The synthesis process involved alkalization-acid hydrolysis and bleaching techniques. Subsequent analyses of nanofiber characteristics were conducted using Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The efficacy of these modified nanofibers in adsorbing CV was quantitatively measured using an Ultraviolet-Visible (UV-Vis) spectrophotometer. The study successfully synthesized nanofibers from sugar palm fiber waste with modifications: PEG-modified nanofibers (NP 2 and NP 24) and citric acid-modified nanofibers (NS 2 and NS 24). These modifications resulted in nanofibers with a smooth, white texture. FTIR analysis of the samples (N, NP 2, NP 24, NS 2, and NS 24) revealed the presence of functional groups essential for cellulose, specifically -OH, C-H, and C-O groups. The addition of citric acid introduced a new group, C=O, albeit with very weak intensity. PEG modifications were evident from the stretching observed in the -OH groups. SEM analysis confirmed the presence of a layer on the nanofibers, attributed to citric acid (NS 2 and NS 24) and PEG (NP 2 and NP 24). XRD results indicated that the pre-and post-modification nanofibers exhibited a semi-crystalline phase. The adsorption mechanism was predominantly guided by Van der Waals electrostatic interactions between the absorbent material and the adsorbate. Intriguingly, the citric acid and PEG modifications did not significantly alter the adsorption outcomes. The adsorption capacity remained stable over time, as evidenced by measurements of 0, 15, 30, 45, 60, 90, and 120 minutes.</p>

Synthesis of 5-benzyl-5-((5-nitropyridin-3yl)methyl)-1,3,5-dithiazinan-5-ium through one-pot reactions, characterization and study as a corrosion retardant in high salinity oil fields.

This study included the preparation of a new heterocyclic compound namely 5-benzyl-5-((5-nitropyridin-3-yl) methyl)-1,3,5-dithiazinan-5-ium (BNPD) by a simple powerful method and an environmentally acceptable. The BNPD compound contains O, N, and S heteroatoms that have been inserted into the chemical structure by one step consisting of several transformations. The BNPD structure has been characterized using several techniques like FT-IR, 1H-NMR, 13C-NMR, and G-C mass. The prepared molecule has been studied as an inhibitor of carbon steel corrosion (N-80), which is generally used in oil fields. The BNPD effectiveness has been studied as an anti-corrosive material in saline water that accompanies the extraction of crude oil. Saline water contains dissolved solids estimated at 239581mg/l, conductivity 254.23 ms/cm, and pH 6.1. The retardant has been evaluated by electrochemical impedance spectroscopy technique (EIS), potentiodynamic polarization technique (PP), scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM/EDX), and weight loss method (WL) at 308K(±1). It was noted that inhibition efficiency increases with increasing BNPD concentration. The results of potentiodynamic polarization showed that the studied inhibitor molecules act as a mixed-type inhibitor, while the results of weight loss showed that these molecules adsorbed on the carbon steel surface through physical and chemical adsorption simultaneously. The results of the SEM/EDX indicated that slight corrosion occurred at the inhibitor was added, where the EDX spectrum of N-80 at 80 mg.dm-3 of inhibitor was noticed approximately similar to the polished carbon steel spectrum. Furthermore, the electronic and physic-chemical characteristics of BNPD have been calculated like EHOMO, ELUMO, energy gap, total energy, lipophilicity coefficient, molecule surface area, molecular volume, molecular polarizability, molar refractivity, dipole moment, solvation energy, theoretical inhibition efficiency, and electrostatic potential surfaces. The BNPD compound has shown wonderful results in corrosion inhibiting, where its efficiency optimum reached 91.14%, 93.60%, and 93.46% for WL, EIS, and PP techniques, respectively. Either theoretical efficiency reached 90.25%.

An insight into fine cassiterite recovery: A novel surfactant-phenylpropylhydroxamic acid and its adsorption mechanism

The effective recovery of fine-grained cassiterite is a difficult problem in tin ore beneficiation. For enhancing the performance of the traditional collector for fine cassiterite flotation, a novel surfactant phenyl propyl hydroxamic acid (PHA) was designed by introducing one ethyl group (–CH2-CH2-) into benzohydroxamic acid (BHA).The study of flotation properties and the adsorption mechanism of PHA onto cassiterite surface were systematically investigated by scanning electron microscopy-energy dispersive X-ray spectroscopy testing (SEM-EDS), adsorption measurements, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and Density functional theory (DFT). The results indicate that PHA has an excellent flotation performance for fine cassiterite compared with BHA and salicylhydroxamic acid (SHA), and the interaction between PHA and the surface of mineral mainly exhibited chemisorption attributed to new Sn-O chemical bonds. Meanwhile, DFT calculations showed that PHA adsorbed on the cassiterite surface via chelating interaction by the formation of a five-membered chelate ring.

Fabrication and Characterization of Eco-Friendly Polystyrene Based Zinc Oxide-Graphite (PS/ZnO-G)

One of the most significant environmental challenges nowadays is the rising manufacturing of non-biodegradable polymer wastes like polystyrene. In order purpose of manufacture environmentally friendly polystyrene that easily decomposes, a solvent approach was used to create polystyrene based zinc oxide- graphite composites. The surface morphology and materials contained in the modified polystyrene were evaluated by scanning electron microscopy-energy dispersive X-ray analysis to verify the dispersion and distribution of the nanoparticles by scanning electron microscopy and the material contents by energy dispersive X-ray analysis. While the crystal structure, chemical bonds, and functions were determined by X-ray Diffraction and Fourier transform infrared, no change in the chemical structure occurred in polystyrene. Thermogravimetric analysis was used to assess the thermal decomposition. And its results found that the temperature of the decomposition was 46.78° lower in zinc oxide and graphite-based polystyrene composites than in pure polystyrene. It came to light that the presence of zinc oxide nanoparticles causes phase separation and consequently impacts the thermal behaviour of graphite-based polystyrene composites. The phase separation was demonstrated by the Thermogravimetric curves showing two degrading steps. This satisfies the urgent demand to synthesize polystyrene that is eco-friendly and easy to thermally decomposition, as well as easy to recycle, which benefits both the environment and the commercial side.

Green synthesis of MnO2-embedded Rauvolfia tetraphylla leaves (MnO2@RTL) for crystal violet dye removal and as an antibacterial agent.

The application of green synthesized nanocomposites for the prevention of environmental pollution is increasing nowadays. Here, a green composite has been synthesized by embedding MnO2 on Rauvolfia tetraphylla leaves using its leaf extract hereinafter termed as MnO2@RTL, and demonstrated for crystal violet (CV) dye removal from simulated and real wastewater. The surface properties of the material were determined by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), and Brunauer-Emmet-Teller (BET) surface area, pHZPC, and zeta potential. The material exhibits a remarkable adsorption capacity of 61.162mg/g at 328K and pH 7. The adsorption was best fitted with Pseudo-second-order kinetic (R2 = 0.998) and a combination of Langmuir and Freundlich isotherm model (R2 = 0.994-0.999). The thermodynamic study revealed spontaneous (ΔG values = - 2.988 to - 4.978kJ/mol) and endothermic (ΔH values = 6.830 to 11.018kJ/mol) adsorption. After adsorption, 80% regeneration occurred with 50% methanol, and recycled up to five times. Advantageously, the material was able to remove CV dye in the presence of coexistent ions and fromindustrial wastewater, confirming field applicability. The adsorption capacity of the material is superior to previously reported materials. The standard deviation and relative standard deviations have been evaluated to be 0.000422-0.000667 and 0.473-0.749%, which suggests the reliability of the experiments. The exhausted material, after recycling, was pyrolyzed to overcome the disposal problem. It was established as a secondary adsorbent with 73% efficiency which makes the material win-win. The material showed antibacterial properties with Staphylococcus aureus bacteria with a zone of inhibition 5mm.

Natural zeolite supported g-C3N4/ZnO/Ag3PO4 composite: A tandem n-n heterojunction for simultaneous photodegradation of dyes under visible and solar irradiation

Various zinc-based ternary composite photocatalysts with variable weight percent ratios of g-C3N4:ZnO/Ag3PO4 in pristine and natural zeolite supportedform were prepared using precipitation and solid-state methods, respectively. X-ray diffraction (XRD), Brunauer, Emmett, and Teller (BET), Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX), Thermogravimetric analysis (TGA/DTA), Fourier Transform Infrared (FTIR), Ultraviolet–Visible Diffuse Reflectance (UV–Vis DRS), and Photoluminescence (PL) techniques were used to investigate the as-produced composites. The photocatalytic efficacy of the developed materials was studied considering methyl orange dye (MeO) and laboratory-prepared mixed dyes as target pollutants. The photodegradation (MeO) performance of the natural zeolite-supported (NZGZA-1) ternary system was found to be 87.1% under optimal working circumstances. The primary active species engaged in MeO decolorization were the holes. The photodegradation efficiency under outdoor experiment yielded 98.2 and 78.9 %, for MeO and mixture of dyes respectively. After five consecutive cycles, the reusability of the supported catalyst was examined, and a 47.2 % decline was recorded at the end of the fifth cycle showing the fairly well stability of the catalyst. The photocatalytic degradation of the studied model pollutant follows pseudo-1st-order kinetics. The present work evidenced beneficial use of natural zeolite as support to ternary photocatalyst systems with enhanced efficiency apart from meeting the criteria for circular economy. Thus, reusing of spent natural zeolite as a support for composite photocatalysts could be considered viable alternative to disposing the same to the environment.

Organic and inorganic pollutants removal from tannery effluent using electrocoagulation technique

Abstract Electrocoagulation is an efficient treatment for the concurrent elimination organic and inorganic contaminants from tannery wastewater. The batch electrocoagulation investigations were carried out using mild steel and aluminium as sacrificial anodes and stainless steel as the cathode. Various operating constraints, such as the electrolyte pH, realistic current density, electrolysis time, effluent concentration and supporting electrolyte concentration were appraised to study their effects on electro-coagulation efficiency. The maximum Total Organic Carbon (TOC) removal has been observed was 90 % and 77 % under optimum operating conditions, and the maximum chromium removal has been recorded was 99 % and 90 % using mild steel and aluminium anodes respectively. The experimental data was also fitted with the first order kinetic model. The experimental data were investigated with the Langmuir and Freundlich adsorption isotherm models. The result shows that the experimental data fitted with the Langmuir isotherm model, with a rate of confidence of 0.98, using mild steel as an anode. The solid sludge and the liquid samples were characterized using the SEM (scanning electron microscopy) EDX (energy dispersive X-ray spectrometry), FT-IR (Fourier transform infrared spectrometer) and UV–Visible (Ultraviolet–visible spectroscopy) analyses. All experimental results show that mild steel was an efficient anode, for the instantaneous elimination of organic and inorganic contaminants from tannery wastewater.

The antimicrobial potential of ZnO-chitosan/pandan leaves: advancing antimicrobial textile technology

This study explores the utilization of natural compounds, including zinc oxide (ZnO) derived from aloe vera, chitosan, and pandan leaves (Pandanus amaryllifolius Roxb) extract, for the development of antimicrobial-coated fabric textiles. The objectives of this research are to optimize the formulation, structural properties, and antimicrobial effectiveness of these textiles through comprehensive characterization techniques, including Fourier Transform Infrared Spectroscopy (FTIR), Particle Size Analysis (PSA), and Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX). The addition of NaOH as a base at pH 13.0 played a crucial role in obtaining smaller particles with improved homogeneity. The XRD analysis confirmed the hexagonal crystalline structure of ZnO in the composite. The use of Chloroacetamide (CAA) binder and NaOH in different molar compositions influenced the coating of ZnO-Chitosan/Pandan leaf on cotton fibers. A molar ratio of 1:2 for CAA and NaOH resulted in the most substantial reduction in the intensity of the carbonyl absorption peak in the FT-IR spectrum, indicating a more complete and robust coating.

Effect of process variables on leaching behavior and kinetics of silver element from waste photovoltaic modules

In order to achieve efficient leaching of silver, in waste photovoltaic panels, the leaching process using nitric acid was investigated. The effects of nitric acid concentration, leaching time, solid–liquid ratio, and leaching temperature on the silver leaching rate were examined. The response surface method was used to establish an experimental model for analyzing and optimizing the leaching experiment. The results showed that the nitric acid concentration had the most significant effect on the leaching rate. The leaching rate of 98.02% was achieved under the following optimal leaching conditions: a nitric acid concentration of 18%, a leaching time of 32 min, a solid–liquid ratio of 1:30, and a leaching temperature of 60 °C. According to the shrinkage nuclear model, the leaching kinetics of silver using nitric acid followed a chemical reaction-controlled process with an apparent activation energy of 42.26 kJ/mol. Scanning electron microscopy–energy-dispersive x-ray spectrometry results of minerals before and after leaching confirmed the efficient recovery of silver in waste photovoltaic cells.