Scanning Electron Microscopy-energy Dispersive X-ray Research Articles

Treatment of Methylene Blue Using Ni-Al/Magnetite Biochar Layered Double Hydroxides Composite by Adsorption

Methylene blue dye is hard to degrade and requires treatment using Ni-Al Layered double hydroxides (LDHs) modified with magnetite biochar (MBC) to form Ni-Al/magnetite biochar composite in overcoming environmental pollution. Material attainment was identified by characterization using X-Ray Diffraction (XRD), Fourier Transform – Infra Red (FT-IR), Branuer Emmet Teller (BET), Scanning Electron Microscopy – Energy Dispersive X-Ray (SEM-EDX) and Vibration Sample Magnetometer (VSM). XRD characterization displays angle 2θ at 11°, 60° is a typical angle of LDH, and angles 22° and 35° of magnetite biochar. FT-IR characterization analysis at wavelength 1381 cm-1 for NO3- group and M-O group at wave number 700 cm-1. C-H group on biochar at 1404 cm-1 and wave number 586 cm-1 for Fe-O group. BET characterization analysis of Ni-Al/MBC has a large surface area and pore volume of 127.310 m²/g and 0.1950 cm³/g. SEM characterization analysis of Ni-Al/MBC has large, coarse pores and non-uniform shape, EDX data shows that there are forming elements such as Ni, Al from LDH and, Fe, C elements from magnetite biochar. pH, kinetics, isotherms, and thermodynamics become influential in adsorption processes. The adsorption capacity of the composite reaches 68.493 mg/g by following the Langmuir equation and adsorption kinetics refers to the Pseudo Second Order (PSO) equation. Adsorption continuity is spontaneous and endothermic. Ni-Al/MBC has stability in the process of adsorbent regeneration up to five adsorption cycles and, therefore can be used as a potential adsorbent in the treatment of methylene blue dye in aqueous environmental pollution. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

MOF-199 and Ni-BTC: Synthesis, Physicochemical Properties, and Catalytic Activity in Oxidation of 5-Hydroxymethylfurfural

Platform chemical 2,5-furandicarboxylic acid (FDCA) has potential applications to replace petroleum-based chemicals. Metal Organic Framework (MOF) can be used as a catalyst to oxidize 5-hydroxymethylfurfural (HMF), producing FDCA. MOF-199 and Ni-BTC were synthesized using solvothermal method with trimesic acid (benzene 1,3,5-tricarboxylic acid/H3BTC) as a linker and Cu or Ni as a metal nod. The physical and chemical properties of catalysts were discovered through characterization using X-ray Diffraction (XRD), Fourier Transform Infra Red (FT-IR), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy - Energy Dispersive X-ray (SEM-EDX), and Ammonia Temperature-programmed Desorption (NH3-TPD). FDCA and its intermediate compounds were produced by converting HMF to FDCA in a small glass batch reactor. The yields of products were then determined by High-Performance Liquid Chromatography (HPLC). HPLC results indicated that there was no DFF (2,5-diformylfuran) signal, indicating that FDCA was formed by FFCA (5-formylfuroic acid) and HMFCA (5-hydroxymethylfuroic acid) formation reaction pathway. The maximum conversion (71%) was obtained using Ni-BTC as a catalyst at 130 °C for 5 h, with FDCA yield of 61.8%. Copyright © 2023 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Green Synthesis, Characterization, and Photocatalytic Activity of Zinc Oxide Nanoparticles on Photodegradation of Naphthol Blue Black Dye

Zinc oxide (ZnO) nanoparticles have been successfully synthesized using water extract of red dragon fruit (Hylocereus polyrhizus) stem with zinc acetate dihydrate as a precursor of ZnO. Chemical compounds contained in the red dragon fruit stem extract, such as phenolics, terpenoids, and steroids, acted as reducing agents, stabilizers, and capping agents. The phase structure, crystallite size, functional groups, shape, and morphology of ZnO nanoparticles were determined by X-ray diffraction (XRD), Fourier Transform infrared (FT-IR) Spectroscopy, and Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The XRD pattern confirmed the crystallinity of synthesized zinc oxide was in the zincite (ZnO) phase with an average crystallite size of 79.09 nm. Spectroscopy FTIR analysis showed that the synthesized ZnO nanoparticles had characteristics similar to the ZnO standard/commercial. SEM-EDX analysis revealed that the synthesized ZnO nanoparticles were spherical, evenly distributed, and homogeneous particle size. The photocatalytic activity of synthesized ZnO nanoparticles was evaluated on the photodegradation of naphthol blue black (NBB) dye. The results showed that the synthesized ZnO nanoparticles have high photocatalytic activity that can degrade NBB dye up to 98.82%. This high photocatalytic activity was obtained at operating parameter conditions with the initial pH of NBB at 2, the dosage of ZnO nanoparticles at 250 mg, and the initial dye concentration at 10 ppm.

Black Tea Waste as Corrosion Inhibitor for Carbon Steel in 0.5 M HCl Medium

Indonesian black tea (BT) waste was utilized as a green corrosion inhibitor for carbon steel (CS) corrosion in a 0.5 M HCl medium. The BT extract was characterized using Fourier transform infra-red. The corrosion inhibition evaluation was studied using conventional weight loss methods, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Further, scanning electron microscopy-energy dispersive X-ray was applied to analyze the surface morphology of pure CS before and after contact with the inhibitor extract. After the addition of inhibitors, CS surface showed a better morphological transformation. The effect of oxygen contamination has also been studied in this research. The corrosion measurements of weight loss, potentiodynamic polarization, and EIS showed that the %IE BT extract was 84.70; 70.00; 72.80% at 0.20 g/L of inhibitor concentration. Adsorption isotherm studies have determined the reaction mechanism between the CS and inhibitor; in which the adsorption follows Langmuir. Gibbs free energy for the three methods is −16.62; −25.34; −24.35 kJ/mol, indicating electrostatic interaction (physisorption) between the metal surface and inhibitor. SEM and focus ion beam show that oxygen contamination can increase the corrosion rate resulting in CS damage. It shows that tea waste products can be used as an alternative corrosion inhibitor.

Dissolution behavior and aging of iron–uranium oxide

Understanding the dissolution behavior of the fuel debris is necessary for the safe decommissioning of Fukushima Daiichi Nuclear Power Plants. The dissolution behavior of FeUO4 compounds formed by a high-temperature reaction of UO2 with iron, a stainless-steel component of reactor structural materials, was investigated under atmospheric conditions. The compounds were prepared in an electric furnace using U3O8 and Fe3O4 as starting materials, and their solid states were analyzed using X-ray diffraction, scanning electron microscopy–energy-dispersive X-ray spectroscopy, and X-ray absorption fine-structure spectroscopy. The fission products were produced via thermal-neutron irradiation. The concentration of nuclides dissolved in water was examined by performing static leaching tests of FeUO4 compounds for up to three months. A redox reaction was proposed to occur between trivalent Fe and pentavalent U ions in the early stage of FeUO4 dissolution. It was thermodynamically deduced that the reduced divalent Fe ion was finally oxidized into a trivalent ion in the presence of dissolved oxygen, and iron hydroxide limited the solubility of Fe. Meanwhile, the concentration of hexavalent U (i.e., uranyl ion) was limited owing to the presence of secondary minerals such as metaschoepite and sodium uranate and subsequently decreased, possibly owing to sorption on Fe oxides, for example. The concentrations of multivalent ions of fission products, such as Ru and Ce, also decreased, likely for the reason above. By contrast, the concentration of soluble Cs ions did not decrease. The validity of this interpretation was supported by comparing the results with the dissolution behavior of a reference sample (Fe-free U3O8).

Enzymatic dual-faced Janus structures based on the hierarchical organic-inorganic hybrid matrix for an effective bioremoval and detoxification of reactive blue-19

A novel, dual-faced, and hierarchical type of Janus hybrid structures (JHSs) was assembled through an in situ growing of lipase@cobalt phosphate sheets on the laccase@copper phosphate sponge-like structures. The chemical and structural information of prepared JHSs was investigated by Scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray diffraction analysis (XRD). The catalytic activity, storage stability, and reusability of JHSs were then investigated. The SEM-EDX analysis clearly confirmed the asymmetric morphology of the fabricated JHSs with two distinct metal distributions. Under optimized synthesis conditions, the prepared JHSs showed 97.8 % and 100 % of laccase and lipase activity, respectively. Compared to the free biocatalysts, the immobilization resulted in ~ a 2-fold increase in laccase and lipase stability at temperatures of >40 °C. The fabricated JHSs maintained 61 % and 90 % of their original laccase and lipase activity upon 12 successive repetition cycles. Up to 80 % of Reactive Blue-19 (RB-19), an anthraquinone-based vinyl sulphone dye, was removed after 5 h treatment with the prepared JHSs (50 % higher than the free forms of laccase and lipase). The dye removal data fitted very well on the pseudo-second-order kinetic model with a rate constant of 0.8 g mg−1 h−1. Following the bioremoval process, bacterial toxicity also decreased by about 70 %. Therefore, the prepared JHSs provide a facile and sustainable approach for the decolorization, biotransformation, and detoxification of RB-19 by integrating enzymatic oxidation and hydrolysis.

Valorization of coconut and banana wastes with petcoke and coal via steam gasification in a fluidized bed reactor

Steam gasification experiments were conducted with coal and petcoke in conjunction with potentially renewable biomass substances, namely coconut shell, coconut husk, and banana peduncle, which are usually considered waste materials. The gasification performance in a bench-scale externally heated fluidized bed gasifier was evaluated based on the product syngas quality and the detailed characterization of feed and product samples using X-ray fluorescence (XRF), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy analysis. This work performed experiments at relatively constant operating parameters: solid feed rate, steam/O2 ratio, feed particle size, and gasification reactor temperature. Biomass waste resources showed an augmentation in the syngas product quality for both the coal and petcoke samples, especially in cold gas efficiency (CGE) and carbon conversion efficiency (CCE). A maximum increase in CCE from 44.3 % to 72 % for the coal sample and from 19.3 % to 36.0 % for the petcoke sample was witnessed, whereas for the CGE, a rise of 35.8 %–91.7 % for the coal and 44.3 %–59.8 % for the petcoke with 80/20 blended biomass waste samples, was observed compared to the coal and petcoke only samples. The maximum hydrogen product gas yield between 53 and 73.7 vol % and combustible gas yields between 62.2 and 86.7 vol % were obtained on a nitrogen gas-free basis during the experiments. The solid residues of different gasification experiments were characterized and analyzed by scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) and field emission-scanning electron microscopy (FE-SEM) analytical techniques to elucidate the high yield of energy-intensive gases. FTIR analysis was performed on all the liquid product samples obtained during the gasification experiments. The presence of alkali and alkaline earth metals (AAEMs) in biomass wastes highlighted the catalytic effect of these elements during the gasification experiments. The current work provides an opportunity to reduce carbon footprints with effective and efficient utilization of conventional energy feedstocks in conjunction with other waste substrates.

Biopesticide Nanoformulations Based on Clove Essential Oil for the Growth Inhibition of Lichens

Clove essential oil with eugenol as the major compound was used to develop a biopesticide formulation for lichens. Due to the suboptimal effectiveness and high volatility, the present research aimed to prepare a stable and effective deliverable nano biopesticide formulation by adding AgNO3 powder to clove essential oil. The analysis was carried out with several variations: Storage time, AgNO3 concentration, and the effect of adding emulsifiers like Tween 80 and PEG 400. Biopesticide formulations were characterized using a ultraviolet-visible spectrophotometer, Fourier transform infrared, pore size analyzer, and scanning electron microscope-energy dispersive X-ray. The effectiveness of inhibiting lichen growth was determined through an inhibition test. The results showed that the effective biopesticide formulation with AgNO3 was obtained at 429?475 nm wavelength, with a particle size of 217 nm and a PI value below 0.5. To reduce the particle size further, the addition of Tween 80 and PEG 400 in the process showed that the particle size achieved was 111.8?172.2 nm with round and irregular morphology, close to the nanoparticle size, and a suitable nanoemulsion formulation. Clove essential oil biopesticide modified with AgNO3, Tween 80, and PEG 400 effectively inhibited lichen growth with an average inhibition zone diameter of 33?37 mm compared to 36.4 mm in positive control and no inhibition in negative controls.. KEYWORDS :Biopesticides, Clove essential oil, Eugenol, Growth inhibition, Lichen, Silver

Pengaruh Variasi Temperatur Tempering Terhadap Struktur Mikro Dan Struktur Kristal Pada Baja Karbon Sebagai Bahan Mandrill

This writing begins with a mandrill that cannot be modified in a company, so the author wants to know the crystal structure and microstructure of the steel, as well as explain the composition contained in the steel being tested. Tests were carried out by observing the crystal structure using an X-Ray Diffractometer (XRD), observing the microstructure and material composition using Scanning Electron Microscopy – Energy Dispersive X-ray (SEM-EDX). The results show that the crystal structure and microstructure are strongly influenced by the quenching and tempering processes. The increase in crystal size occurred after the tempering process at 425° C from 34.33 nm to 52.31 nm. There was a decrease in dislocation density after tempering at 425° C from 0.00085 lines/mm2 to 0.00085 lines/mm2. Likewise, the micro strain after the tempering process at 425°C decreased from 0.25 (ε) to 0.19 (ε). The test material has several compositions such as iron (Fe), oxygen (O), manganese (Mn), sodium (Na), chromium (Cr), calcium (Ca) and carbon (C). Microstructure testing showed a decrease in iron Fe atoms after the tempering process from 65.79% to 42.96%, a decrease in atoms also occurred in manganese from 0.51% to 0.34% after the tempering process. There was an increase in oxygen atoms after the tempering process from 33.31% to 54.23%, an increase in the atomic presentation also occurred in sodium (Na) from 0.33% to 2.46% after the tempering process

TUZLUCA (IĞDIR-TÜRKİYE) ÇEVRESİNDE YÜZEYLENEN MİYOSEN YAŞLI KAYAÇLARIN MİNERALOJİK VE JEOKİMYASAL ÖZELLİKLERİ

In this study, Miocene lithostratigraphic units (Turabi, Çincavat and Tuzluca formations) outcropping in the Neogene Kağızman-Tuzluca Basin in the west of Iğdır province were studied. The units are represented by evaporatic, carbonate and clayey rocks. The study aims to determine the mineralogical and geochemical properties of these rocks and to interpret the paleoenvironmental conditions. XRD (X-ray diffraction) whole rock and clay fraction analyzes, OM (Optical Microscope) studies, element determination with XRF (X-ray fluorescence) and, FE-SEM / EDS (Field emission scanning electron microscopy-energy dispersive X-ray spectrometry) studies of rock samples taken along the sections measured in the field were carried out for this purpose. Quartz, feldspar, mica, calcite, gypsum and halite minerals were determined in whole rock compositions of the samples. Smectite, illite, chlorite and paligorskite minerals were found in the clay fractions. It has been determined that feldspars altered to smectite by SEM and EDS studies. Optical microscopy and paleoenvironment studies indicate that the origins of gypsum, halite and palygorskite minerals are authigenic. It was also determined that calcite was authigenic and detritic, while chlorite, illite, quartz, feldspar and mica were detrital. The predominance of smectite, as well as the presence of chlorite, illite and palygorskite indicate that the basin developed under alkaline conditions, mostly hot and humid, and occasionally arid and cold conditions. In geochemical analyzes, the positive correlation of SiO2 with other major oxides (excluding CaO, MgO and SO3) is the input of clay and clastic materials, while the negative correlation of SiO2 with SO3 and CaO is associated with the decrease in the rate of CaSO4 sediments as a result of shallowing of the basin due to evaporation of water.

Synthesis and characterization of magnetic nanoparticles via co‐precipitation: Application and assessment in anaerobic digested wastewater

AbstractNanotechnology is a widely applied technology in environmental remediation, medicine, chemical processes and catalysis. The Development and modification of nanoparticles for wastewater treatment via anaerobic digestion have gained much interest over the years. This study synthesized six different magnetic nanoparticles (MNPs) via the co‐precipitation method. These MNPs were characterized via scanning electron microscopy/energy dispersive X‐ray (SEM/EDX), Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD) and Brunauer–Emmett–Teller analysis. The SEM/EDX, FTIR and XRD affirmed the success of the synthesis of MNPs. The MNPs were furthermore explored to enhance the anaerobic digestion of wastewater to generate biogas. This was done by conducting a biochemical methane potential (BMP) assay, where seven bioreactors were digested for 21 and 30 days at 35°C. In comparison with the control (no MNPs), which had a removal efficiency of <68%, the results showed that the addition of MNPs to the BMP system demonstrated good degradation of >70% chemical oxyggen demand (COD) and turbidity removal efficiencies. There was a 20% increase in methane yield for the BMP setups with MNP additives compared with the control bioreactor.

Evaluation of the cytotoxicity, antioxidant activity, and molecular docking of biogenic zinc oxide nanoparticles derived from pumpkin seeds.

This study aimed to investigate the characterization of zinc oxide nanoparticles (ZnONPs) produced from Cucurbita pepo L. (pumpkin seeds) and their selective cytotoxic effectiveness on human colon cancer cells (HCT 116) and African Green Monkey Kidney, Vero cells. The study also investigated the antioxidant activity of ZnONPs. The study also examined ZnONPs' antioxidant properties. This was motivated by the limited research on the comparative cytotoxic effects of ZnO NPs on normal and HCT116 cells. The ZnO NPs were characterized using Fourier-transform infrared spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Transmission Electron Microscope/Selected Area Electron Diffraction (TEM/SAED), and Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX) for determination of chemical fingerprinting, heat stability, size, and morphology of the elements, respectively. Based on the results, ZnO NPs from pumpkins were found to be less than 5 μm and agglomerates in nature. Furthermore, the ZnO NPs fingerprinting and SEM-EDX element analysis were similar to previous literature, suggesting the sample was proven as ZnO NPs. The ZnO NPs also stable at a temperature of 380°C indicating that the green material is quite robust at 60-400°C. The cell viability of Vero cells and HCT 116 cell line were measured at two different time points (24 and 48 h) to assess the cytotoxicity effects of ZnO NP on these cells using AlamarBlue assay. Cytotoxic results have shown that ZnO NPs did not inhibit Vero cells but were slightly toxic to cancer cells, with a dose-response curve IC50 = ~409.7 μg/mL. This green synthesis of ZnO NPs was found to be non-toxic to normal cells but has a slight cytotoxicity effect on HCT 116 cells. A theoretical study used molecular docking to investigate nanoparticle interaction with cyclin-dependent kinase 2 (CDK2), exploring its mechanism in inhibiting CDK2's role in cancer. Further study should be carried out to determine suitable concentrations for cytotoxicity studies. Additionally, DPPH has a significant antioxidant capacity, with an IC50 of 142.857 μg/mL. RESEARCH HIGHLIGHTS: Pumpkin seed extracts facilitated a rapid, high-yielding, and environmentally friendly synthesis of ZnO nanoparticles. Spectrophotometric analysis was used to investigate the optical properties, scalability, size, shape, dispersity, and stability of ZnO NPs. The cytotoxicity of ZnO NPs on Vero and HCT 116 cells was assessed, showing no inhibition of Vero cells and cytotoxicity of cancer cells. The DPPH assay was also used to investigate the antioxidant potential of biogenic nanoparticles. A molecular docking study was performed to investigate the interaction of ZnO NPs with CDK2 and to explore the mechanism by which they inhibit CDK2's role in cancer.

Exploring the antibacterial and dermatitis-mitigating properties of chicken egg white-synthesized zinc oxide nano whiskers.

Zinc oxide nanoparticles (ZnO-NPs) have garnered considerable interest in biomedical research primarily owing to their prospective therapeutic implications in combatting pathogenic diseases and microbial infections. The primary objective of this study was to examine the biosynthesis of zinc oxide nanowhiskers (ZnO-NWs) using chicken egg white (albumin) as a bio-template. Furthermore, this study aimed to explore the potential biomedical applications of ZnO NWs in the context of infectious diseases. The NWs synthesized through biological processes were observed using electron microscopy, which allowed for detailed examination of their characteristics. The results of these investigations indicated that the NWs exhibited a size distribution ranging from approximately 10 to 100 nm. Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) mapping analyses successfully corroborated the size, dimensions, and presence of biological constituents during their formation. In this study, XTT assay and confocal imaging were employed to provide evidence of the efficacy of ZnO-NWs in the eradication of bacterial biofilms. The target bacterial strains were Staphylococcus aureus and Escherichia coli. Furthermore, we sought to address pertinent concerns regarding the biocompatibility of the ZnO-NWs. This was achieved through comprehensive evaluation of the absence of cytotoxicity in normal HEK-293T and erythrocytes. The findings of this investigation unequivocally confirmed the biocompatibility of the ZnO-NWs. The biosynthesized ZnO-NWs demonstrated a noteworthy capacity to mitigate the dermatitis-induced consequences induced by Staphylococcus aureus in murine models after a therapeutic intervention lasting for one week. This study presents a comprehensive examination of the biosynthesis of zinc oxide nanowhiskers (ZnO-NWs) derived from chicken egg whites. These findings highlight the considerable potential of biosynthesized ZnO-NWs as a viable option for the development of therapeutic agents targeting infectious diseases. The antibacterial efficacy of ZnO-NWs against both susceptible and antibiotic-resistant bacterial strains, as well as their ability to eradicate biofilms, suggests their promising role in combating infectious diseases. Furthermore, the confirmed biocompatibility of ZnO-NWs opens avenues for their safe use in biomedical applications. Overall, this research underscores the therapeutic promise of ZnO-NWs and their potential significance in future biomedical advancements.

The novel ternary phase CaAl2±xCr2±xO7 in the Al2O3–CaO–Cr2O3 system: What is the chromium solubility?

Recently, in the Al2O3–CaO–Cr2O3 system, a Cr3+ ternary phase named wuboraite (CaAl2Cr2O7) was synthesized for the first time in an air atmosphere, which later showed an undetermined hint of solid solubility between Cr3+ and Al3+ in different atmosphere. In the present investigation, the solubility limits (or x values) of the CaAl2±xCr2±xO7 were determined by conducting high-temperature equilibrium experiments in both air and N2 atmospheres with the various proportionate mixtures of CaO, Al2O3, and Cr2O3, and subsequently using powder X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) analysis. In the air atmosphere, the Cr richest end-member of the Wuboraite solid solution phase is CaAl1.77Cr2.23O7 (or x = 0.23), while that of Al richest end-member is CaAl2.18Cr1.82O7 (or x = 0.18). Whereas, in the N2 atmosphere, the Cr richest end-member of the wuboraite solid solution phase is CaAl1.77Cr2.23O7 (or x = 0.23), while that of Al richest end-member is CaAl2.15Cr1.85O7 (or x = 0.15).

INVESTIGATING MAGNETIC, DIELECTRIC, OPTIC AND MORPHOLOGIC PROPERTIES OF NANO-NICKEL OXIDE-DOPED NdFeO3

In this investigation, [Formula: see text]-Fe2O3 was prepared via co-precipitation and nano-NiO and NdFeO3 were synthesized using the sol–gel method. For NdFe[Formula: see text]Ni[Formula: see text]O3 synthesis, Nd2O3, [Formula: see text]-Fe2O3, and nano-NiO compounds were mixed via the solid state method. The effect of each component and that of nano-NiO on the NdFe[Formula: see text]Ni[Formula: see text]O3 crystal properties was characterized by using X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray (SEM-EDX), ultraviolet-visible (UV–Vis), vibrating sample magnetometer (VSM), impedance and bandgap analyses. The orthorhombic perovskite structure was confirmed by the XRD data. With the doping of nano-NiO, the unit cell volume was found to decrease. The UV–Vis spectroscopy showed that the nano-NiO-doped optical bandgap ([Formula: see text]) had increased. The VSM analysis demonstrated that by doping nano-NiO to weak ferromagnetic NdFeO3, the resulting NdFe[Formula: see text]Ni[Formula: see text]O3 was rendered superparamagnetic. The real and imaginary parts of dielectric permittivity ([Formula: see text]′ and [Formula: see text]″) and the loss tangent (tan[Formula: see text]) characteristic of the compounds were measured at AC-signaled frequencies of 100 Hz–10 MHz and a voltage range of 0–20 V DC. The increase in active charge transmission with the doping of nano-NiO reduced the [Formula: see text]′ values. In addition, the large differences between the [Formula: see text]′ values were thought to be caused by the breakdown voltage ([Formula: see text]) effect of the compounds. The [Formula: see text]″ and tan[Formula: see text] changes revealed the dipole formation of the compounds at different voltages, their relaxation regions and their polarization mechanism type. The dielectric loss behavior of the compounds demonstrated their good dielectric material properties. This study investigated the effect of method difference and doped material particle size on magnetic and dielectric properties.

Thermodynamic behavior and kinetic analysis of carbothermal reduction process of low-grade oxysulfur lead–zinc ore

During the exploitation of sphalerite resources, a considerable amount of low-grade oxysulfur Pb–Zn deposits is generated, which poses a significant threat to the environment and soil and water conservation in mining areas. Therefore, low-grade Pb–Zn resources urgently require source emission reduction and appropriate utilization. This study applied a mineral technology and conducted X-ray diffraction and scanning electron microscopy–energy dispersive X-ray spectroscopy to investigate the phase transformation and the mechanism underlying the volatilization of Pb and Zn at different times and temperatures. The Pb–Zn volatilization kinetics of a low-grade oxysulfur Pb–Zn ore by a one-step pyrometallurgical process in an argon atmosphere was studied, and the effects of different temperature conditions on the Zn volatilization process were investigated. The results showed that the Zn-containing phase in the raw material was decomposed to ZnO and ZnS upon heating. Moreover, ZnO was reduced via carbothermal reduction, whereas ZnS was reduced via a CaO-assisted carbothermal reaction and volatilized in the form of gaseous Zn. In the Pb-containing phase, PbSO4 generated PbO, Pb, and PbS in the presence of Fe, FeS, and CaO. PbO was volatilized in the form of gaseous Pb through carbothermal reduction and interactions between PbS and PbO. The Pb–Zn volatilization reaction conformed to the shrinking core model with a constant size, and the volatilization-based removal of Pb and Zn process was controlled by internal diffusion. A macroscopic kinetic model of the reaction was established on the basis of experimental data. The apparent activation energy of Pb and Zn volatilization was 163.90 and 328.19 kJ/mol, respectively. This study promotes the utilization of the low-grade oxysulfur Pb–Zn ore through a pyrometallurgical method to provide theoretical support for large-scale industrial treatments.

Synthesis and characterization of enhanced carbon nanotube-supported PtRuBi alloy catalyst for ethylene glycol electrooxidation

At present, carbon nanotube (CNT)-supported Pt-based catalysts are prepared by the sodium borohydride (SBH) method for catalytic ethylene glycol (EG) electrooxidation. The structural and morphology surface analyses of these catalysts are characterized by X-ray diffraction (XRD), scanning electron microscopy-energy dispersive X-ray (SEM-EDX) and mapping analysis, transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). In addition, the catalytic activity and electrochemical surface area (ECSA) of the catalysts are examined by cyclic voltammetry (CV). The 10 % PtRuBi(80-10-10)/CNT catalyst exhibited the best catalytic activity with a specific activity of 6.10 mA/cm2 and an ECSA value of 488.42 m2/g. Furthermore, it is observed that it exhibited the best stability and resistance by chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) analyses. It can be a promising anode catalyst for direct EG fuel cells.

High-efficiency recyclable reduced graphene oxide-tin oxide nanocomposite catalyst for esterification

Graphene oxide (GO) possesses 2D nanostructures and was synthesized indigenously via the enhanced Hummer method. It is well-accepted that the redox approach is a distinctive technique to fabricate GO on an expanded scale. Here, reduced graphene oxide-tin oxide (SnO2-rGO) nanocomposite material was produced for application as an efficient heterogeneous solid acid catalyst esterification reaction. Fourier transform infrared analysis was carried out to validate the incidence of oxygen functional groups in GO and SnO2-rGO nanocomposite. The Raman spectra of GO and SnO2-rGO nanocomposite have been simulated to get stable structure and functional groups. To get surface morphological and structural features, powder X-ray diffraction, scanning electron microscope-energy dispersive X-ray spectra, transmission electron microscope and high resolution-TEM analysis, and thermogravimetric analysis were delineated during this experimental study. It is seen that the catalyst has high efficiency for esterification reaction. The maximum efficiency (96% yield) was obtained when a 1:3 (acetic acid to benzyl alcohol) molar ratio, catalyst (25 mg), temperature (60 0C), and time (4 h) were maintained. The SnO2-rGO nanocomposite was recycled several times with a minimal loss of its efficiency.

Aluminium dross waste utilization for phosphate removal and recovery from aqueous environment: Operational feasibility development

The need to minimize eutrophication in water bodies and the shortage of phosphate rock reserves has stimulated the search for sequestration and recovery of phosphate from alternative sources, including wastewater. In this study, aluminium dross (AD), a smelting industry waste/by-product, was converted to high-value material by encapsulation in calcium alginate (Ca-Alg) beads, viz. Ca-Alg-AD and utilized for adsorptive/uptake removal and phosphate recovery from an aqueous environment. Encapsulation of AD in alginate beads solves serious operational difficulties of using raw AD material directly due to density difference constraining efficient contact of AD with pollutants present in water and post-treatment recovery of AD material. The phosphate removal was evaluated in both batch and continuous flow operation modes. The batch adsorption study revealed 96.86% phosphate removal from 10 mg L−1 of initial phosphate concentration in 70 min of optimal contact time. Further, the phosphate removal potential of Ca-Alg-AD beads turned out to be independent of solution pH, with an average of 95.93 ± 1.40 % phosphate removal in the 2–9 pH range. The result reflects phosphate adsorption on Ca-Alg-AD beads following a second-order pseudo-kinetic model. Ca-Alg-AD beads-based adsorption followed Freundlich and Langmuir isotherm models. Further, a continuous packed bed column study revealed a total phosphate adsorption capacity of 1.089 mg g−1. The chemical composition, physical stability, and surface properties of Ca-Alg-AD beads were analyzed by means of state-of-the-art analytical techniques, such as Scanning Electron Microscopy-Energy Dispersive X-ray spectroscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetry/Differential Thermal Analysis (TG/DTA). These characterization techniques comprehend the mechanism and influence of surface properties and morphology on the phosphate adsorption behaviour, which induce the involvement of multiple mechanisms such as ligand complexation, ion exchange, and electrostatic attraction for phosphate adsorption on Ca-Alg-AD beads.

Double perovskite material of highly active, monoclinic, ordered Ni2ZnMoO6 for an effective quasi-solid state supercapacitor

In the present study, monoclinic Ni2ZnMoO6 double perovskites (monoclinic NZMO DP) electrodes were synthesized using hydrothermal method for supercapacitors application. The structural, elemental, vibrational, and optical characterization were analyzed using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy Dispersive X-ray analysis (HR-SEM & EDX), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), Fourier Transform Infrared spectroscopy(FTIR) and UV-Visible Diffusion reflectance Spectroscopy (UV-DRS). A monoclinic structure with a space group of P 2/m and lattice parameters of a = 11.4377, b = 9.2961, c = 6.8301, and β = 97.710 was fitted using Rietveld refinement, and the cell volume was 719.6458 Å3. The surface area of monoclinic NZMO DP was found to be 50.45 m2 g−1 with a pore volume of 0.15 cm3 g−1. Electrochemical characterization was done using Cyclic voltammetry (CV), Electrochemical Impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) measurements. An equivalent-circuit model R(CR)(CR) is iterated to interpret the EIS responses. The Rct found to be less than 100 ohms in the present study can be attributed to Mott variable range hopping (VRH) conduction. The GCD analysis of ASC monoclinic NZMO DP//AC in 6 M KOH at 0.5 Ag−1 in the potential window of 0–1.6 V yields a maximum specific capacitance of 160.45 Fg−1. Excellent electrochemical stability of the monoclinic NZMO DP was ascertained by the specific capacitance retention of the electrode material at 91.37 % after 6000 cycles. The ASC-NZMO monoclinic DP shows an excellent power density of 646.25 W/kg with an energy density of 20.53 Wh/kg. The excellent power storage efficiency and application possibilities of supercapacitors make them a promising technology in various fields.