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Alumina‐supported PtSn catalysts have been industrialized as the major catalysts for propane dehydrogenation, where Sn serves as an essential promoter. Herein, we synthesized a variety of Sn‐doped alumina supports by regulating the precipitation order of Sn and Al precursors as follows: Sn precursor precipitated before Al, coprecipitated with Al, precipitated immediately after Al, or precipitates after 2 h of Al. The effect of Sn promoter on the surface acidic properties of alumina and, ultimately, on propane dehydrogenation was further investigated. The Sn species introduced by coprecipitation in alumina created additional surface strong acid sites, attributed to more Sn4+ species on the surface, which are able to remain stable during the subsequent treatment. Consequently, the coprecipitated Sn species in the corresponding catalyst donate more electrons to Pt and reduce the metal particle size. As a result, the catalyst with Pt supported on the coprecipitated support (Sn+Al) exhibits superior initial propane conversion (43.2%) and stability (kd = 0.035 h−1). This study provides new insight into the interaction between the two key components, tin promoter and alumina support, of Pt/Sn‐Al2O3 catalysts. [ABSTRACT FROM AUTHOR]

The neutralization of acidic solutions containing U (IV) and Ce (III) at room temperature in glove box atmosphere and in the presence of dithionite results in coprecipitation of these elements as amorphous solid solutions CexU1–xO2±y. The solubilities of the precipitates with different mole fractions (x) of Ce(OH)3 (x = 0.01 or 0.1) were determined in 1 M NaClO4 solutions between pH 2.2 and 12.8 under reducing conditions. The solids were investigated by a variety of methods (chemical analysis, SEM‐EDX, XRD, XPS, XAS) to determine the nature of the solid solutions formed, their composition and the valence state of Ce and U. X‐ray photoelectron spectroscopy confirmed the oxidation states of the solids both before and after the equilibration as Ce (III) and U (IV). The amorphous coprecipitates reached equilibrium relatively fast (∼1 week). The release of Ce from the coprecipitates was totally dominated by the release of uranium over the whole pH range. The Ce concentrations decrease slightly with the decrease of Ce content in the solid, suggesting that CexU1–xO2±y solids behave thermodynamically as solid solutions. The concentrations of U in equilibrium with the coprecipitate were in excellent agreement with the solubility of UO2(s) under reducing conditions reported in the literature. The conditional solubility product of Ce(OH)3 from the coprecipitate was several orders of magnitude (∼4 in the near neutral pH range and ∼18 in the acidic range) lower than that of pure Ce(OH)3(s). The activities and activity coefficients of Ce(OH)3(s) in the coprecipitate were also estimated. Activity coefficients are much less than 1, indicating that the mixing of Ce(OH)3 with UO2 is highly favorable. [ABSTRACT FROM AUTHOR]

We have proposed to produce a 229Th/225Ac generator by neutron irradiation of the 228Ra target, which is a decay product from 232Th. The solutions containing 232Th and 228Ra were obtained through the thermal chemical conversion method to dissolve the ThO2. Then, the separation of 228Ra from thorium solutions through co-precipitation with magnesium was studied. It was confirmed that radium is coprecipitated by this method. It was also confirmed that the precipitated magnesium carbonate can be easily converted to magnesium oxide. The decontamination of thorium from precipitated radium was investigated, and it was found that a rough decontamination of thorium was achieved by co-precipitation methods. The decontamination of thorium depends on the chemical conversion conditions and the dissolution methods used. [ABSTRACT FROM AUTHOR]

A modified two-step coprecipitation method has been formulated to prepare a series of model CuZnO/Al2O3 catalysts for methanol synthesis from syngas. Evaluation at industrially relevant condition showed slightly higher activity and much higher stability for model catalysts than for a commercial catalyst. Due to the same CuZn-binary precursor, the model catalysts had similar structural properties with large specific surface area and pore volume, small CuO crystallites and good reducibility, resembling that of the commercial catalyst. However, the model catalysts showed much better uniformity of alumina distribution, which accounted for their better performance. Strong positive correlation between the deactivation rate and the coefficient of variation of Al/Zn indicates the uniformity of alumina distribution plays an important role in determining stability. Specifically, CuZnO/Al2O3 catalysts with alumina distributed more uniformly had higher stability. This work demonstrated that the formulated modified two-step coprecipitation could provide excellent CuZnO/Al2O3 catalysts for industrial applications. Additionally, it also affords new clues for the development of even better industrial catalysts. [ABSTRACT FROM AUTHOR]

The neutralization of acidic solutions containing U (IV) and Ce (III) at room temperature in glove box atmosphere and in the presence of dithionite results in coprecipitation of these elements as amorphous solid solutions CexU1–xO2±y. The solubilities of the precipitates with different mole fractions (x) of Ce(OH)3 (x = 0.01 or 0.1) were determined in 1 M NaClO4 solutions between pH 2.2 and 12.8 under reducing conditions. The solids were investigated by a variety of methods (chemical analysis, SEM‐EDX, XRD, XPS, XAS) to determine the nature of the solid solutions formed, their composition and the valence state of Ce and U. X‐ray photoelectron spectroscopy confirmed the oxidation states of the solids both before and after the equilibration as Ce (III) and U (IV). The amorphous coprecipitates reached equilibrium relatively fast (∼1 week). The release of Ce from the coprecipitates was totally dominated by the release of uranium over the whole pH range. The Ce concentrations decrease slightly with the decrease of Ce content in the solid, suggesting that CexU1–xO2±y solids behave thermodynamically as solid solutions. The concentrations of U in equilibrium with the coprecipitate were in excellent agreement with the solubility of UO2(s) under reducing conditions reported in the literature. The conditional solubility product of Ce(OH)3 from the coprecipitate was several orders of magnitude (∼4 in the near neutral pH range and ∼18 in the acidic range) lower than that of pure Ce(OH)3(s). The activities and activity coefficients of Ce(OH)3(s) in the coprecipitate were also estimated. Activity coefficients are much less than 1, indicating that the mixing of Ce(OH)3 with UO2 is highly favorable. [ABSTRACT FROM AUTHOR]

The present study reveals the synthesis of Iron oxide nanoparticles (IONPs) by varying the molar ratio of ferric (Fe3+) to ferrous (Fe2+) ions via chemical coprecipitation method for the study of cationic distribution of Fe‐ions and its potential application for magnetic hyperthermia therapy (MHT). X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X‐ray photoelectron spectroscopy (XPS), were used to characterize the physicochemical properties. Several structural parameters were estimated using the Rietveld refinement, resulting in structural modelling verified by magnetic characteristics. A vibrating sample magnetometer (VSM) assessed the magnetic hysteresis loop at room temperature in a field range of ±15 kOe, revealing superparamagnetic behavior for the ratio Fe2+/Fe3+ 1:2. The saturation magnetization (Ms) of IONPs increased with the increasing Fe2+ concentration and attained a maximum value of 60.21 emu g−1 at a molar ratio of 2:1. The potential of the inductive heating capability of IONPs in an alternating current magnetic field (AMF) was studied to treat localized MHT. The changes in magnetic properties and inductive heating properties of IONPs are associated with the cationic distribution of Fe2+ at the tetrahedral (A) and octahedral (B) sites of crystal structure. The variation in cationic properties at the A and B sites may result in varying/tuneable magnetic properties, affecting the overall heating profiles of hyperthermia. [ABSTRACT FROM AUTHOR]

Spinel cobalt ferrite (CoFe2O4) nanoparticles have garnered significant interest due to their versatile properties and potential applications. Among the various factors influencing their properties, annealing temperature stands out as a crucial parameter. In this comprehensive analysis, we studied the effects of various annealing temperatures (400, 500, 600, and 700 °C) on the structural, optical, morphological, magnetic, and photocatalytic characteristics of CoFe2O4 nanoparticles. X-ray powder diffraction (XRD) studies reveal the crystalline structure of CoFe2O4 nanoparticles. The crystallite size was increased from 13.544 nm to 20.312 nm with the increasing annealing temperature from 400 to 700 °C. The effect of annealing temperature on cationic-anionic interaction of the nanomaterials is studied through Fourier transform infrared spectroscopy (FTIR). Morphological and elemental composition of the nanomaterials is evaluated through Field Effect Scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). Changes in annealing temperature lead to variations in particle size, morphology, and surface area, influencing their catalytic activity. UV–visible spectroscopy (UV–Vis) and photoluminiscene spectroscopy (PL) were employed to investigate the optical properties of CoFe2O4 nanoparticles. Annealing temperature variation influences the band gap energy, affecting the absorption and emission properties of the nanoparticles. Tauc's plot was employed to obtain the band gap of the nanomaterials. The band gap was decreased from 2.33 eV to 1.92 eV with rise in annealing temperature. An emission peak at 465.80 nm was observed through PL spectroscopy. The magnetic properties of CoFe2O4 nanoparticles, including saturation magnetization and coercivity, are examined using a vibrating sample magnetometer (VSM). The sample annealed at 400 °C has shown highest magnetic parameters with saturation magnetization, coercivity, and remanent magnetization of 51.53 emu/g, 1860 Oe, and 17.5 emu/g respectively. Annealing temperature variation alters the magnetic behavior, affecting the nanoparticles' utility in magnetic and photocatalytic applications. The photocatalytic performance of CoFe2O4 nanoparticles is examined through degradation of methylene blue dye under UV–Visible irradiation. The sample annealed at 400 °C exhibited the highest photocatalytic efficiency, achieving 74.46% discoloration. The involvement of hydroxyl ion (OH−) and singlet oxygen ion (O2−) was verified through a Scavenger test using Isopropyl Alcohol (IPA) and Disodium Ethylenediaminetetraacetic Acid (EDTA 2NA), respectively. The kinetics of dye removal was analyzed using various rate models. Additionally, the material's stability was evaluated by calculating its recycling efficiency over four successive cycles. [ABSTRACT FROM AUTHOR]

The objective of this research is to determine how to obtain magnetic iron nanoparticles through the coprecipitation technique using FeCl3 and FeSO4 as raw materials in an aqueous extract of purple corn (Zea mays L) as a stabilizing state. In recent decades, the manufacture and use of magnetic iron nanoparticles has created great importance and expectation due to their various applications in different areas, among which stands out their ability to eliminate waste that pollutes the environment. Because research design is experimental in nature due to the different samples carried out in laboratories. The selection of corn was randomized due to the ease of access to the product from a group of farmers who were previously trained to plant, cultivate, harvest, and dry purple corn. The corn antioxidants were extracted with boiling water, and the synthesis of the nanoparticles was performed by mixing FeCl3, FeSO4 in the extract solution at a temperature of 25°C for 30 min with agitation at a pH above 11 with the addition of NaOH. Characterization was performed by UV-Vis spectrophotometer. The coprecipitation method produced the magnetic iron nanoparticles using FeCl3 and FeSO4 as reagents and the aqueous extract of purple corn. The practical implications that this research will have are diverse, as theoretically it will be possible to carry out experiments with other types of corn to see the different results, as well as to use it to carry out different tests in places highly contaminated with heavy metals. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles are extensively utilized in various fields, particularly in biomedical applications. For such uses, nanoparticles must meet specific criteria, including precise size, morphology, physico-chemical properties, stability, and biocompatibility. Microwave-assisted co-precipitation offers an efficient method for producing water-soluble nanoparticles. Functionalization with citrate during synthesis is crucial for achieving a stable colloidal solution. This study aims to compare the effectiveness of conventional co-precipitation with microwave-assisted co-precipitation. The synthesized nanoparticles were characterized using TEM, DLS, FTIR, XRD, and magnetic measurements. The findings indicate that the in situ citrate functionalization during synthesis results in stable, non-aggregated nanoparticles. [ABSTRACT FROM AUTHOR]

A new coprecipitation procedure was improved for preconcentration-separation and detection of trace propineb. In order to coprecipitate propineb, 8-hydroxyquinoline (8HQ) and copper (II) were used as a precipitating agent and a carrier element, respectively. Using the stoichiometric relationship with zinc, propineb was determined. The critical parameters on the quantitative recoveries of analyte such as pH, mass of precipitating agent, mass of carrier element, and sample volume were studied. The influences of the matrix components were also tested. The preconcentration factor was 80. The limit of detection (LOD), and the limit of quantification (LOQ) for propineb were 0.114 mg L−1 and 0.38 mg L−1, respectively. Copper(II)-8-hydroxyquinoline coprecipitation was applied to determine propineb in vegetable and fruit samples from Kayseri-Turkey with satisfactory results. Flame atomic absorption spectrometry (FAAS) was utilized for measurements of model and real sample solutions. [ABSTRACT FROM AUTHOR]

Spinel oxides are a type of material that can be used in a wide range of applications, such as photocatalysis, hydrogen production and environmental protection. In this respect, calcium aluminate (CaAl2O4) and chromate (CaCr2O4) spinels were synthesized in this study by the coprecipitation method using potash solution as a precipitant. CaAl2O4 and CaCr2O4 spinels were annealed at 900 and 1100°C, respectively, for different periods. The obtained spinels were first characterized by thermal analysis, and the phase composition of the oxides was analysed using X-ray diffraction. Hydroxyl groups and absorbed water in the obtained precipitates disappeared after calcination and were observed via Fourier transform infrared spectroscopy. BET and SEM/EDS analyses were also used to determine the total surface area of the powder particles, the size of the grains and the morphology of the powders of the synthesized nanoparticles, respectively. The structural and morphological analyses revealed the formation of single-phase CaAl2O4 and dual-phase CaCr2O4, with specific surfaces for each spinel of 44.2165 and 5.7190 m2 g−1, respectively. Moreover, DFT calculations were performed on the materials, and the direct bandgaps of these spinels were found to be 4.365 eV for CaAl2O4 and 2.256 eV for CaCr2O4. The results indicated that different compositions led to different optical bandgaps. Finally, the results indicate that due to the suitable characteristics and properties of the produced spinel oxides, they are among the promising materials that may be employed as semiconductors for various applications. [ABSTRACT FROM AUTHOR]

The neutralization of acidic solutions containing U (IV) and Ce (III) at room temperature in glove box atmosphere and in the presence of dithionite results in coprecipitation of these elements as amorphous solid solutions CexU1–xO2±y. The solubilities of the precipitates with different mole fractions (x) of Ce(OH)3 (x = 0.01 or 0.1) were determined in 1 M NaClO4 solutions between pH 2.2 and 12.8 under reducing conditions. The solids were investigated by a variety of methods (chemical analysis, SEM-EDX, XRD, XPS, XAS) to determine the nature of the solid solutions formed, their composition and the valence state of Ce and U. X-ray photoelectron spectroscopy confirmed the oxidation states of the solids both before and after the equilibration as Ce (III) and U (IV). The amorphous coprecipitates reached equilibrium relatively fast (∼1 week). The release of Ce from the coprecipitates was totally dominated by the release of uranium over the whole pH range. The Ce concentrations decrease slightly with the decrease of Ce content in the solid, suggesting that CexU1–xO2±y solids behave thermodynamically as solid solutions. The concentrations of U in equilibrium with the coprecipitate were in excellent agreement with the solubility of UO2(s) under reducing conditions reported in the literature. The conditional solubility product of Ce(OH)3 from the coprecipitate was several orders of magnitude (∼4 in the near neutral pH range and ∼18 in the acidic range) lower than that of pure Ce(OH)3(s). The activities and activity coefficients of Ce(OH)3(s) in the coprecipitate were also estimated. Activity coefficients are much less than 1, indicating that the mixing of Ce(OH)3 with UO2 is highly favorable.

[Display omitted] Ultra-high nickel single-crystal cathode materials have become the most promising for lithium-ion batteries. However, the preparation of ultra-high nickel single-crystal precursors by a continuous coprecipitation method has the disadvantages of large particle size, wide distribution, poor morphology. The extent of the inhomogeneous reactions can be more severe in single-crystal cathodes with larger particle size. Herein, the coprecipitation method with a solid concentrator was adopted, and citrate sodium was used as a complexing agent to improve the physical properties of precursors and electrochemical performance of single-crystal cathode materials. By analyzing the morphology and agglomeration mechanism of the precursor nucleuses under different pH values, it was found that hexagonal nanosheets grew along the 101 direction, and the primary particles showed thicker at pH of 11.4. The hexagonal nanosheets grew along the 001 direction, and the primary particles showed finer at pH of 12.2. The morphology and particle size uniformity of the secondary particles formed by agglomeration at these two pH values showed poor. However, hexagonal nanosheets grew synergistically along the 001 and 101 directions at pH of 11.8, so the primary particles with uniform particle size gradually agglomerated, and then the secondary particles with ultra-small particle size and uniform distribution obtained. Compared to materials prepared by the traditional continuous coprecipitation method, the precursor displays a smaller particle size(D 50 = 1.8 µm), higher sphericity, uniformity and denser internal structure. In order to evaluate the performance of Ni 0.94 Co 0.04 Mn 0.02 (OH) 2 with ultra-small particle size, the sintering conditions of LiNi 0.94 Co 0.04 Mn 0.02 O 2 need to be explored. It was found that the LiNi 0.94 Co 0.04 Mn 0.02 O 2 cathode material prepared at 790 °C exhibited higher discharge capacity, cycle and rate performance, compared to materials prepared at 760 °C and 820 °C. We further utilized TEM, EPMA, and XPS to test the internal structure and valence state of LiNi 0.94 Co 0.04 Mn 0.02 O 2 cathode material. The results show that the LiNi 0.94 Co 0.04 Mn 0.02 O 2 calcined at 790 °C has a good single crystal structure. The LiNi 0.94 Co 0.04 Mn 0.02 O 2 cathode materials inherited the structure and particle size of Ni 0.94 Co 0.04 Mn 0.02 (OH) 2 precursors, and displayed discharge capacity of 194.7 mAh/g and capacity retention rate of 89.8 % after 100 cycles at 1 C. The microstructure and phase transition of the as-prepared cathode material are well-maintained after long-term cycling, without obvious inter-crystalline micro-crack. The results indicate that its electrochemical performance is better than that of cathode materials with precursors prepared by a continuous coprecipitation method. This work provides new insights for the preparation of small-particle-size precursor and single-crystal cathode materials. [ABSTRACT FROM AUTHOR]

Abstract Biopolymers embedded with nanoparticles of metal oxides (MOs) demonstrate a wide range of bio-functions. Chitosan-incorporated MOs are an interesting class of support matrices for enhancing the biological function, compared to other support matrices. Therefore, the importance of this study lies in exploiting chitosan as a carrier not of one metal as in previous studies, but of two metals in the form of a nanocomposite to carry out several biological functions. The coprecipitation approach was employed to synthesize chitosan/Fe2O3/ZnO-nanocomposite in the present research. The characterization of chitosan/Fe2O3/ZnO-nanocomposite was performed to find out the morphology and dispersion properties of chitosan/Fe2O3/ZnO-nanocomposite. The X-ray diffraction (XRD) investigation revealed that these were crystalline. Fourier transforms infrared (FTIR) spectrum bands were viewed at 400/cm and 900/cm, due to the stretching vibration of Fe and Zn oxygen bond. TEM showed that chitosan/Fe2O3/ZnO-nanocomposite was of 20–95 nm in size. chitosan/Fe2O3/ZnO-nanocomposite exhibited inhibitory potential against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Candida albicans with inhibition zones of 25 ± 0.1, 28 ± 0.2, 27 ± 0.1, and 27 ± 0.2 mm, respectively while didn’t inhibited Aspergillus niger. MIC value of nanocomposite was 15.62 ± 0.33 µg/mL for C. albicans, B. subtilis and E. coli, while it was 62.50 ± 0.66 µg/mL for Pseudomonas aeruginosa. Ranged values of nanocomposite MBC (15.62 ± 0.33 to 125 ± 1 µg/mL) were attributed to all tested bacteria. Different concentrations of chitosan/Fe2O3/ZnO-nanocomposite MBC (25, 50, and 75%) reflected anti-biofilm activity against E. coli (85.0, 93.2, and 96.0%), B. subtilis (84.88, 92.21, and 96.99%), S. aureus 81.64, 90.52, and 94.64%) and P. aurogenosa (90.11, 94.43, and 98.24%), respectively. The differences in the levels of antimicrobial activities may depend on the type of examined microbes. Antioxidant activity of chitosan/Fe2O3/ZnO-nanocomposite was recorded with excellent IC50 values of 16.06 and 32.6 µg/mL using DPPH and ABTS scavenging, respectively. Wound heal by chitosan/Fe2O3/ZnO-nanocomposite was achieved with 100% compared to the untreated cells (76.75% of wound closer). The cytotoxicity outcomes showed that the IC50 of the chitosan/Fe2O3/ZnO-nanocomposite was 564.32 ± 1.46 µg/mL normal WI-38 cells. Based on the achieved findings, the chitosan/Fe2O3/ZnO-nanocomposite is a very promising agent for perform pharmacological activities.

Biopolymers embedded with nanoparticles of metal oxides (MOs) demonstrate a wide range of bio-functions. Chitosan-incorporated MOs are an interesting class of support matrices for enhancing the biological function, compared to other support matrices. Therefore, the importance of this study lies in exploiting chitosan as a carrier not of one metal as in previous studies, but of two metals in the form of a nanocomposite to carry out several biological functions. The coprecipitation approach was employed to synthesize chitosan/Fe2O3/ZnO-nanocomposite in the present research. The characterization of chitosan/Fe2O3/ZnO-nanocomposite was performed to find out the morphology and dispersion properties of chitosan/Fe2O3/ZnO-nanocomposite. The X-ray diffraction (XRD) investigation revealed that these were crystalline. Fourier transforms infrared (FTIR) spectrum bands were viewed at 400/cm and 900/cm, due to the stretching vibration of Fe and Zn oxygen bond. TEM showed that chitosan/Fe2O3/ZnO-nanocomposite was of 20–95 nm in size. chitosan/Fe2O3/ZnO-nanocomposite exhibited inhibitory potential against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Candida albicans with inhibition zones of 25 ± 0.1, 28 ± 0.2, 27 ± 0.1, and 27 ± 0.2 mm, respectively while didn't inhibited Aspergillus niger. MIC value of nanocomposite was 15.62 ± 0.33 µg/mL for C. albicans, B. subtilis and E. coli, while it was 62.50 ± 0.66 µg/mL for Pseudomonas aeruginosa. Ranged values of nanocomposite MBC (15.62 ± 0.33 to 125 ± 1 µg/mL) were attributed to all tested bacteria. Different concentrations of chitosan/Fe2O3/ZnO-nanocomposite MBC (25, 50, and 75%) reflected anti-biofilm activity against E. coli (85.0, 93.2, and 96.0%), B. subtilis (84.88, 92.21, and 96.99%), S. aureus 81.64, 90.52, and 94.64%) and P. aurogenosa (90.11, 94.43, and 98.24%), respectively. The differences in the levels of antimicrobial activities may depend on the type of examined microbes. Antioxidant activity of chitosan/Fe2O3/ZnO-nanocomposite was recorded with excellent IC50 values of 16.06 and 32.6 µg/mL using DPPH and ABTS scavenging, respectively. Wound heal by chitosan/Fe2O3/ZnO-nanocomposite was achieved with 100% compared to the untreated cells (76.75% of wound closer). The cytotoxicity outcomes showed that the IC50 of the chitosan/Fe2O3/ZnO-nanocomposite was 564.32 ± 1.46 µg/mL normal WI-38 cells. Based on the achieved findings, the chitosan/Fe2O3/ZnO-nanocomposite is a very promising agent for perform pharmacological activities. [ABSTRACT FROM AUTHOR]

Coprecipitation facilitates the incorporation of Zn into the lattice of Fe (hydr)oxide, which is a crucial mechanism causing low Zn bioavailability in widespread Zn-deficient soils. Zn isotopes are a potential indicator of the coprecipitation of Zn and Fe (hydr)oxides in soils. However, the Zn isotope fractionation caused by coprecipitation with amorphous Fe (hydr)oxides (e.g., ferrihydrite) and the impact of environmentally relevant conditions remain unknown. Here, the molecular mechanism and impact factor of Zn isotope fractionation during Zn2+-Fe3+ coprecipitation under natural soil conditions (including different pH values and initial Zn/Fe ratios) were investigated by combining isotope ratio measurements, extended X-ray absorption fine structure (EXAFS) analyses, and density functional theory (DFT) geometry optimization. The results show that aqueous Zn (Zn aq) can be complexed on the ferrihydrite surface (Zn ads) with positive isotope fractionation (Δ66Zn ads–aq = 0.42 ± 0.09 ‰) or directly incorporated into the ferrihydrite lattice with slightly negative isotope fractionation (Δ66Zn stru-aq = −0.08 ± 0.03 ‰). In addition, over time, the surface-complexed Zn can further transform to a layered structure on the surface but exhibits limited Zn isotope fractionation. According to Zn K-edge EXAFS, the Zn isotope fractionation of surface complexation and incorporation of Zn aq are related to the decrease in the Zn–O bond strength in the order surface complexed Zn (R Zn–O = 2.00 Å) > aqueous Zn (R Zn–O = 2.08 Å) > directly incorporated Zn (R Zn–O = 2.06–2.07 Å with slight distortion). The limited Zn isotope fractionation associated with the transformation of Zn ads is related to the reconfiguration of Zn ads during the nucleation of octahedral Zn layer structures. Furthermore, the primary process controlling Zn isotope fractionation is different under varying experimental conditions, leading to distinct Zn isotope fractionation between the bulk solid and solution during Zn–Fe coprecipitation. Low pH values (5.0–6.0) and initial Zn/Fe ratios (0.01–0.02) favor the direct precipitation of Zn aq , resulting in slightly negative Zn isotope fractionation between the bulk solid and solution. In contrast, high pH values (7.0–7.5) and initial Zn/Fe ratios (0.1–0.2) favor surface complexation and the transformation of Zn ads , leading to heavy Zn isotope enrichment in the bulk solid. These findings offer novel insights into the primary mechanism through which Fe (hydr)oxides regulate Zn bioavailability in Zn-deficient soils and provide experimental evidence supporting the potential application of Zn isotopes as an indicator for comprehending the fate of Zn controlled by Fe (hydr)oxides in soils. [ABSTRACT FROM AUTHOR]

In this paper, NiMn layered double hydroxide (NiMn LDH) was quickly synthesized by coprecipitation method. Then NiMn LDH nanosheets and graphene oxide (GO) nanosheets were obtained by ultrasonic exfoliation technology, which were combined with each other by electrostatic force to obtain NiMn LDH–GO composites. The material was characterized by various techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectrometer. The results of morphology and structure characterization showed that NiMn LDH–GO composite was successfully synthesized and modified it on the surface of glass carbon electrode (GCE), and LDHs were distributed on the surface of GO. Then NiMn LDH-ERGO/GCE was prepared by green and pollution-free electrochemical reduction method. Cyclic voltammetry, differential pulse voltammetry and electrochemical impedance were used to study the electrochemical properties. The results showed that NiMn LDH-ERGO/GCE could realize the simultaneous determination of ascorbic acid, dopamine, uric acid in phosphate buffer solution, and the detection limits were severally 4.11 μM in the linear range of 23.32–235.15 μM, 0.03 μM in the linear range of 0.83–3.15 μM and 0.14 μM in the linear range of 1.18–5.67 μM (S/N = 3.0). In addition, NiMn LDH-ERGO/GCE showed good stability, reproducibility, and anti-interference ability. [ABSTRACT FROM AUTHOR]

Substitute Natural Gas (SNG) is receiving discernible attention as a fuel for the next generations because of the growing energy demand, and fossil fuels are depleting. On the other hand, CO2 emissions are already increasing, so catalytic conversion of CO2 to SNG is a promising way to reduce atmospheric CO2. However, CO2 conversion is not so easy because of its stable properties. So, there is a need for a suitable catalyst that can solve problems such as CO2 conversion, CH4 yield, catalyst deactivation and related issues. Here, we report the effect of the catalyst preparation method and the effect of precipitating agents on the problems mentioned earlier. The 5 series of Al2O3-supported Ni-based and Ni–Fe bimetallic catalysts are prepared by impregnation and coprecipitation methods and characterized by H2-TPR, XRD, H2-TPD, and CO2-TPD, NH3-TPD techniques. The reactions are carried out with TPSR by using a pulse injection technique, which showed a range of CH4 formation and CO2 conversion with a CO2:H2 ratio of 1:4. The 15(Ni–Fe)/Al2O3 showed almost 2 times better conversion and 1.5 times yield at a lower temperature (300 °C) compared to the other prepared catalysts. These findings are promising and suggest that Ni–Fe catalysts prepared by coprecipitation method are favoured for SNG production and could lead to more efficient and cost-effective process development. [ABSTRACT FROM AUTHOR]

Indomethacin (INDO) has a mechanism of action based on inhibiting fatty acids cyclooxygenase activity within the inflammation process. The action mechanism could be correlated with possible anticancer activity, but its high toxicity in normal tissues has made therapy difficult. By the coprecipitation method, the drug carried in a layered double hydroxides (LDH) hybrid matrix would reduce its undesired effects by promoting chemotherapeutic redirection. Therefore, different samples containing INDO intercalated in LDH were synthesized at temperatures of 50, 70, and 90 °C and synthesis times of 8, 16, 24, and 48 h, seeking the best structural organization. X-ray diffraction (XRD), vibrational Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), spectrophotometric analysis in UV-VIS, and differential thermogravimetric analysis (TGA/DTA) were used for characterization. Our results indicate that higher temperatures and longer synthesis time through coprecipitation reduce the possibility of INDO intercalation. However, it was possible to establish a time of 16 h and a temperature of 50 °C as the best conditions for intercalation. In vitro results confirmed the cell viability potential and anticancer activity in the LDH-INDO sample (16 h and 50 °C) for gastric cancer (AGP01, ACP02, and ACP03), breast cancer (MDA-MB-231 and MCF-7), melanoma (SK-MEL-19), lung fibroblast (MRC-5), and non-neoplastic gastric tissue (MN01) by MTT assay. Cell proliferation was inhibited, demonstrating higher and lower toxicity against MDA-MB-231 and SK-MEL-19. Thus, a clinical redirection of INDO is suggested as an integral and adjunctive anticancer medication in chemotherapy treatment. [ABSTRACT FROM AUTHOR]

Doping of Hydroxyapatite (HA) with foreign ions is known as a chemical approach to improve its physicochemical characteristics and expand its biomedical applications. In the current paper, Pt-doped HA (Pt-HA) was synthesized by the co-precipitation method, and the product was characterized using conventional techniques. The XRD analysis results show that the as-synthesized Pt-HA powder exhibits apatite characteristics with lower degrees of crystallinity compared to pure hydroxyapatite, and no new phase or impurity is found. The SEM observations suggest the plate-shaped particles with homogeneous surfaces in which doping of hydroxyapatite with Pt ions led to a decrease in the length of HA particles. The EDS analysis highlighted the purity of the samples and confirmed the presence of Ca, P, O, and Pt elements in the Pt-HA sample. FTIR spectroscopy revealed the presence of the various vibrational modes corresponding to PO43−, OH− and CO32− functional groups. The mean particle size measurement of the as-prepared HA and Pt-HA samples, using the dynamic Light Scattering (DLS) analysis confirmed a decrease in particle size in the Pt-doped HA sample compared to pure HA. TGA results indicated that the prepared Pt-doped HA sample has good thermal stability. [ABSTRACT FROM AUTHOR]

CdO nanoparticles codoped with Ni, Zn have been produced through co-precipitation. The study of structural properties is performed using X-ray diffraction (XRD) as well as field emission scanning electron microscopy (FESEM). Energy-dispersive X-ray spectroscopy (EDX) is utilised to examine the compositional properties of Ni and Zn doped CdO nanoparticles. Ni and Zn doped CdO nanoparticles exhibited a pure cubic phase, as revealed by XRD. The X-ray photoelectron spectroscopy (XPS) method is used to evaluate the chemical and electronic states of the atoms. Codoping caused a redshift in the band gap of the CdO, which was determined by Diffused reflectance spectroscopy (DRS). In a study of their photocatalytic activity, Crystal Violet (CV) dye degradation under sun light exposure was compared with pristine CdO activity. A significant improvement in photocatalytic activity was observed in the degradation of CV due to codoping. Within exposure of 180 min, degradation of CV took place upto 99% by highly doped CdO (NZC3). [ABSTRACT FROM AUTHOR]

Ultra-small magnetic Fe3O4 nanoparticles are successfully synthesized in basic solutions by using the radiolytic method of the partial reduction in FeIII in the presence of poly-acrylate (PA), or by using the coprecipitation method of FeIII and FeII salts in the presence of PA. The optical, structural, and magnetic properties of the nanoparticles were examined using UV–Vis absorption spectroscopy, high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and SQUID magnetization measurements. The HRTEM and XRD analysis confirmed the formation of ultra-small magnetite nanoparticles in a spinel structure, with a smaller size for radiation-induced particles coated by PA (5.2 nm) than for coprecipitated PA-coated nanoparticles (11 nm). From magnetization measurements, it is shown that the nanoparticles are superparamagnetic at room temperature. The magnetization saturation value Ms = 50.1 A m2 kg−1 of radiation-induced nanoparticles at 60 kGy is higher than Ms = 18.2 A m2 kg−1 for coprecipitated nanoparticles. Both values are compared with nanoparticles coated with other stabilizers in the literature. [ABSTRACT FROM AUTHOR]

Abstract Extensive investigations have been carried out on spinel mixed transition metal oxide-based materials for high-performance electrochemical energy storage applications. In this study, mesoporous Mn-substituted MnxZn1−xCo2O4 (ZMC) ternary oxide microspheres (x = 0, 0.3, 0.5, 0.7, and 1) were fabricated as electrode materials for supercapacitors through a facile coprecipitation method. Electron microscopy analysis revealed the formation of microspheres comprising interconnected aggregates of nanoparticles. Furthermore, the substitution of Mn into ZnCo2O4 significantly improved the surface area of the synthesized samples. The electrochemical test results demonstrate that the ZMC3 oxide microspheres with an optimal Mn substitution exhibited enhanced performance, displaying the largest specific capacitance of 589.9 F g−1 at 1 A g−1. Additionally, the ZMC3 electrode maintained a capacitance retention of 92.1% after 1000 cycles and exhibited a significant rate capability at a current density of 10 A g−1. This improved performance can be ascribed to the synergistic effects of multiple metals resulting from Mn substitution, along with an increase in the surface area, which tailors the redox behavior of ZnCo2O4 (ZC) and facilitates charge transfer. These findings indicate that the incorporation of Mn into mixed transition metal oxides holds promise as an effective strategy for designing high-performance electrodes for energy storage applications.

This study deals with the preparation of magnetite nanoparticles (NPs) via a coprecipitation method using several precipitation bases: binary precipitator (NH4OH), mono precipitator (NaOH), and weak precipitator (Ca(OH)2). The prepared magnetite NPs were identified using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, surface area analysis, magnetic properties, Fourier-transformed infrared spectra (FT-IR), and ultra-violet UV–visible spectra. As a result, the phases of the produced magnetite NPs were unaffected by the use of various bases, but their crystallite sizes were affected. It was found that the binary base provided the smallest crystallite size, the mono base provided an average size, and the weak base provided the largest crystallite size. The UV–visible absorption spectroscopy investigation revealed that the absorption and the energy gap rose with a reduction in nanoparticle size. The prepared magnetite NPs were used to manufacture polymeric-based nanocomposites employed as protective shields from low-energy X-rays that are light in weight. These samples were identified using XRD, atomic force microscopy (AFM), and FT-IR spectroscopy. The crystallite size was slightly larger than it was in the case of magnetite NPs. This is consistent with the results of AFM. The interference between the two phases was observed in the results of the FT-IR spectra. The effects of the size of the magnetite NPs on the attenuation tests, linear attenuation coefficient, mass attenuation coefficient, half-value layer, and mean free path were investigated. The results showed that the efficiency of using manufactured shields increases with the decrease in the NPs size of the magnetite used as a reinforcement phase for a range of low operating voltages.

Yttria-stabilized zirconia (YSZ), which exhibits a tetragonal phase, finds widespread application in the realm of high-temperature solid electrolytes. In the context of this research endeavor, a concerted effort was undertaken to procure a stable and controlled tetragonal phase structure within 5 mol% yttria-stabilized zirconia (5 YSZ) by modulating the precipitation rate of YSZ sols in three distinct precipitation environments, namely acidic (AC), near to neutral (NE), and alkaline (AL) conditions. Through the characterization of 5 YSZ compounds synthesized in these various environments, encompassing an assessment of their elemental composition, phase structure, local structure, and microscale morphology, it was discerned that under acidic conditions, the product exhibited non-uniform elemental distribution, pronounced agglomeration, and an abundance of hydroxyl groups, all of which proved detrimental to the stability of the tetragonal phase, resulting in the presence of 40.63% monoclinic phase. Conversely, under alkaline conditions, substantial agglomeration and hydroxyl group presence were also noted, with 34.7% monoclinic phase in the product. In stark contrast, under the condition which is near to neutral, the product demonstrated uniform elemental distribution, excellent dispersion characteristics, and a virtual absence of hydroxyl groups. The tetragonal phase structure remained stable and homogeneous, with almost negligible monoclinic phase content. Subsequent ceramic processing resulted in the highest attainable density (99.7%), coupled with the highest ionic conductivity at 850 °C (35.2 mS/cm). This study underscores that pH control during coprecipitation reactions stands as a robust and effective methodology for achieving a stable tetragonal phase structure.

Fe2O3: Ni (1–9 mol.%) nanoparticles (NPs) were synthesized using the co-precipitation method and calcined at 500∘C for 12 h. The crystallite size, phase, crystallinity, and structural parameters were analyzed via powder X-ray diffraction. The Bragg reflections confirmed that the synthesized NPs crystallize in a pure hexagonal crystal structure with space group R-3c. Surface morphology analysis revealed agglomerated NPs of irregular sizes and shapes. Energy Dispersive X-ray Analysis confirmed the presence of Fe, O, and Ni elements, as well as the purity of the sample. Both the direct band gap energy and crystallite size decreased with increasing dopant concentration. Detailed studies were conducted on the photoluminescence and anticancer properties. The CIE coordinates indicated a color tuning from blue to green in the visible region. CIE coordinates and CCT values ranging between 2860 to 9547 k demonstrated that the synthesized nanophosphor material meets the requirements of display technology. Additionally, anticancer properties were investigated using HeLa cells and compared with the standard drug cisplatin for biomedical applications. Electrochemical investigations revealed super capacitance values ranging from 93.43 to 149.13 F/g at a scan rate of 10 mV/s with increasing Ni2+ concentration. Therefore, the synthesized Ni2+-doped hematite NPs show great promise in display technology, the biomedical field, and as supercapacitors in energy storage devices.

Extensive investigations have been carried out on spinel mixed transition metal oxide-based materials for high-performance electrochemical energy storage applications. In this study, mesoporous Mn-substituted MnxZn1−xCo2O4 (ZMC) ternary oxide microspheres (x = 0, 0.3, 0.5, 0.7, and 1) were fabricated as electrode materials for supercapacitors through a facile coprecipitation method. Electron microscopy analysis revealed the formation of microspheres comprising interconnected aggregates of nanoparticles. Furthermore, the substitution of Mn into ZnCo2O4 significantly improved the surface area of the synthesized samples. The electrochemical test results demonstrate that the ZMC3 oxide microspheres with an optimal Mn substitution exhibited enhanced performance, displaying the largest specific capacitance of 589.9 F g−1 at 1 A g−1. Additionally, the ZMC3 electrode maintained a capacitance retention of 92.1% after 1000 cycles and exhibited a significant rate capability at a current density of 10 A g−1. This improved performance can be ascribed to the synergistic effects of multiple metals resulting from Mn substitution, along with an increase in the surface area, which tailors the redox behavior of ZnCo2O4 (ZC) and facilitates charge transfer. These findings indicate that the incorporation of Mn into mixed transition metal oxides holds promise as an effective strategy for designing high-performance electrodes for energy storage applications. [ABSTRACT FROM AUTHOR]

Preconcentration of strontium and barium as complexes with 11 organic reagents by coprecipitation with organic co-precipitants for their subsequent determination by X-ray fluorescence spectrometry is studied. The most effective systems turned out to be those included reagents from bisazosubstituted chromotropic acids, nitchromazo and chlorophosphonazo III. Complexes of these metals are virtually quantitatively coprecipitated as pairs with cations of the brilliant green dye, of the collector is an associate of an excess of the analytical reagent with cations of this dye. It is shown that the additional use of polyvinyl butyral as an indifferent co-precipitant ensures not only the almost complete extraction of these elements from solutions, but also the preparation of emitter concentrates suitable for X-ray fluorescence measurements using the standard-background technique. High efficiency allows, under optimal conditions, the achievement of very low limits of detection (IUPAC): 0.03 μg/mL Sr and 0.19 μg/mL Ba, even in working with small samples (by volume). [ABSTRACT FROM AUTHOR]

The influence of high‐intensity ultrasound (E = 42.2 W*s/mL) and coprecipitation processes with micellar casein concentrate (0.5, 1.5% w/w) on improving whey protein recovery during Ricotta cheese elaboration was evaluated. Acid and sweet whey were used. Whey treatment (control, ultrasonicated whey, coprecipitation process and ultrasonication + coprecipitation) was used as the independent variable in a completely randomised design. Since neither acidification nor pH adjustment was required, sonication reduced processing time (~6.6%). Coprecipitation (1.5%) enhanced the cheese yield generating textural defects. Softer textures were obtained by using ultrasonication and coprecipitation, suggesting the possibility of producing ricotta cheeses with higher yields and unique technological features. [ABSTRACT FROM AUTHOR]

Calcium phosphate (CaP) particles immobilizing antibacterial agents have the potential to be used as dental disinfectants. In this study, we fabricated CaP particles with immobilized ciprofloxacin (CF), a commonly prescribed antibacterial agent, via a coprecipitation process using a supersaturated CaP solution. As the aging time in the coprecipitation process increased from 2 to 24 h, the CaP phase in the resulting particles transformed from amorphous to low-crystalline hydroxyapatite, and their Ca/P elemental ratio, yield, and CF content increased. Despite the higher CF content, the particles aged for 24 h displayed a slower release of CF in a physiological salt solution, most likely owing to their crystallized matrix (less soluble hydroxyapatite), than those aged for 2 h, whose matrix was amorphous CaP. Both particles exhibited antibacterial and antibiofilm activities along with an acid-neutralizing effect against the major oral bacteria, Streptococcus mutans, Porphyromonas gingivalis, and Actinomyces naeslundii, in a dose-dependent manner, although their dose–response relationship was slightly different. The aging time in the coprecipitation process was identified as a governing factor affecting the physicochemical properties of the resulting CF-immobilized CaP particles and their functionality as a dental disinfectant. [ABSTRACT FROM AUTHOR]

The low sensitivity of working electrodes is usually the bottleneck of the electrochemical testing method. In this work, bismuth antimonate nanosheets have excellent electrochemical performance and are used as the modified materials for glassy carbon electrodes. Bismuth antimonate nanosheets were prepared by a simple coprecipitation method. By changing the calcination temperature and holding time, the effects of these factors on the morphology and structure of the bismuth antimonate nanosheets were investigated. The bismuth antimonate-modified electrode was used for the electrochemical detection of benzoic acid. The results showed that a pair of semi-reversible redox peaks appeared at − 0.48 V and + 0.05 V, and the intensity of the redox peaks gradually increased with the increase of benzoic acid concentration and scan rate. The bismuth antimonate nanomaterial-modified glassy carbon electrode has a wide linear detection range (0.0002–2 mM), low detection limit (0.053 µM) and good cycling performance for detecting benzoic acid. The good electrochemical performance shows that bismuth antimonate nanomaterials have potential application value in the detection of benzoic acid. The glassy carbon electrode modified by bismuth antimonate nanosheets can effectively detect benzoic acid, with linear detection range (0.0002–2 mM) and detection limit (0.053 µM) and good repeatability [ABSTRACT FROM AUTHOR]

ZnO and Zn(0.97-x)Al0.03MnxO (x = 0.00 (AlMnZ0), 0.04 (AlMnZ4), 0.05 (AlMnZ5) and 0.06 (AlMnZ6)) nanopowders that have been synthesized in powder form by using coprecipitation method at powder-based low temperature are zinc chloride (Sigma Aldrich), manganese (II) chloride tetrahydrate (Sigma Aldrich), and aluminum chloride hexahydrate (Sigma Aldrich). The powder of zinc chloride, aluminum chloride hexahydrate and manganese (II) chloride are dissolved in 0.5 M HCl, then a precipitating agent is added in the form of NaOH 5 M base into the solution by slowly dropping NaOH 5 M solution into the precursor until a pH of 10 is reached which causes the clear and transparent solution turns into milky white. In order for the reaction to run perfectly, the stirring process is carried out in a hot plate stirrer for 90 minutes at a temperature of 85 °C. After the solution is formed, it is washed with distilled water repeatedly until there is no impurities and it is filtered with filter paper to separate the precipitate from the solution. X-ray Diffraction (XRD) and Ultra Violet Visible (UV-VIS) Spectroscopy have been used to characterize ZnO nanopowder products through (Al+Mn) doping. The results show that AlMnZ0, AlMnZ4, AlMnz5 and AlMnZ6 nanopowder has the form of a hexagonal wurtzite crystal phase with a crystal size of ~38.03881-47.57561 nm. The optical band gap of ZnO nanopowder can be increased by atomic doping (Al+Mn). The increase in the optical band gap of AlMnZ0, AlMnZ4, AlMnZ5 and AlMnZ6 nanopowder is related to the Burstein-Moss effect, that is when (Al+Mn) atoms are successfully incorporated into ZnO nanopowders, there is a vacancy of the oxygen atom in the host crystal. [ABSTRACT FROM AUTHOR]

Xerogels and powders of solid solutions based on zirconium dioxide are synthesized by the method of the coprecipitation of hydroxides from aqueous solutions of nitrate salts of zirconium, yttrium, aluminum, and cerium with an aqueous solution of ammonia. The characteristics of the resulting materials are studied. The influence of stabilizers and additives on their synthesis, sintering, and properties is assessed. [ABSTRACT FROM AUTHOR]

The gas anti-solvent (GAS) process utilizing compressed carbon dioxide as an anti-solvent was applied to prepare coprecipitated particles between ketoconazole (KET), a poorly water-soluble drug substance, and nicotinamide (NIC), a water-soluble carrier. KET-NIC solid dispersion was also prepared by solvent evaporation and compared with the coprecipitated particles obtained from GAS process. DSC results indicated that KET formed eutectic with NIC at a weight ratio of 7:3. The results showed that the KET-NIC coprecipitated particles prepared by the GAS process, at an initial weight ratio of 1:1.5 in ethanolic solution, had suitable particle morphology and exhibited a remarkably higher dissolution than solid dispersion, physical mixture, and unprocessed KET. The formation of a simple eutectic mixture between KET and NIC in the coprecipitates prepared by both processes was confirmed by DSC, FTIR spectroscopy and powder X-ray diffraction. The enhanced dissolution of the GAS coprecipitated particles might be attributed to the eutectic formation, the improved wettability and hydrophilic microenvironment by the water-soluble carrier, the lower crystallinity, and the smaller size of the drug crystals. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) nanostructures with the general formula Zn1-xMnxO were made using a simple and affordable wet chemical coprecipitation method. X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), and scanning electron microscopy (SEM) were used to examine the structure and morphology of the produced samples. All of the prepared oxides were found to have a single crystalline phase that is ZnO-specific and has a wurtzite structure. It is found that DC conductivity rises with temperature and a steady drop in both AC and DC conductivity with Mn concentration is seen, which might be attributed to the creation of a grain boundary defect barrier. Complex impedance analysis is used to distinguish the grain and grain boundary contribution to the system. The parameters dielectric constant (k) and dielectric loss (tan δ) decreased as the frequency increased, and as the Mn concentration increased. With increasing temperatures, the dielectric constant and loss both increased. [ABSTRACT FROM AUTHOR]

This study deals with the preparation of magnetite nanoparticles (NPs) via a coprecipitation method using several precipitation bases: binary precipitator (NH4OH), mono precipitator (NaOH), and weak precipitator (Ca(OH)2). The prepared magnetite NPs were identified using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, surface area analysis, magnetic properties, Fourier-transformed infrared spectra (FT-IR), and ultra-violet UV–visible spectra. As a result, the phases of the produced magnetite NPs were unaffected by the use of various bases, but their crystallite sizes were affected. It was found that the binary base provided the smallest crystallite size, the mono base provided an average size, and the weak base provided the largest crystallite size. The UV–visible absorption spectroscopy investigation revealed that the absorption and the energy gap rose with a reduction in nanoparticle size. The prepared magnetite NPs were used to manufacture polymeric-based nanocomposites employed as protective shields from low-energy X-rays that are light in weight. These samples were identified using XRD, atomic force microscopy (AFM), and FT-IR spectroscopy. The crystallite size was slightly larger than it was in the case of magnetite NPs. This is consistent with the results of AFM. The interference between the two phases was observed in the results of the FT-IR spectra. The effects of the size of the magnetite NPs on the attenuation tests, linear attenuation coefficient, mass attenuation coefficient, half-value layer, and mean free path were investigated. The results showed that the efficiency of using manufactured shields increases with the decrease in the NPs size of the magnetite used as a reinforcement phase for a range of low operating voltages. [ABSTRACT FROM AUTHOR]

[Display omitted] • The CeCoMnO x spinel-type catalyst prepared using oxalic acid precipitant has a more favorable physicochemical structure for NO conversion than that prepared using alkaline precipitant. • 400 °C is the optimum calcination temperature for oxalic acid precipitated CeCoMnO x spinel for NH 3 -SCR reaction. • The oxalic acid precipitated CeCoMnO x calcined at 400 °C has nearly 100 % NO conversion at 100–200 °C at GHSV = 15,000 mL·g−1·h−1. • An interface-enhanced redox macrocycle mechanism incorporating acid cycling is proposed for oxalic acid precipitated CeCoMnO x catalysts. CeCoMnO x spinel-type catalysts for the selective catalytic reduction of NO using NH 3 (NH 3 -SCR) are usually prepared by alkaline co-precipitation. In this paper, a series of CeCoMnO x spinel-type catalysts with different calcination temperatures were prepared by acidic oxalate co-precipitation. The physicochemical structures and NH 3 -SCR activities of the CeCoMnO x spinel-type catalysts prepared by oxalate co-precipitation and conventional ammonia co-precipitation were systematically compared. The results show that the CeCoMnO x spinel-type catalysts prepared by the oxalate precipitation method (CeCoMnO x -C) have larger specific surface area, more mesopores and surface active sites, stronger redox properties and adsorption activation properties than those prepared by the traditional ammonia co-precipitation method at 400 °C (CeCoMnO x -N-400), and thus CeCoMnO x -C have better low-temperature NH 3 -SCR performance. At the same calcination temperature of 400 °C, the NO conversion of CeCoMnO x -C-400 exceeds 89 % and approaches 100 % within the reaction temperature of 100–125 °C, which is 14.8 %-2.5 % higher than that of CeCoMnO x -N-400 at 100–125 °C. In addition, the enhanced redox and acid cycle matching mechanisms on the CeCoMnO x -C surface, as well as the enhanced monoadsorption Eley-Rideal (E-R) and double adsorption Langmuir-Hinshelwood (L-H) reaction mechanisms, are also derived from XPS and in situ DRIFTS characterization. [ABSTRACT FROM AUTHOR]

The large‐scale application of water electrolysis, for clean H2 production, requires the development of eco‐friendly and low‐cost electrocatalysts with high activity for hydrogen evolution reaction (HER) in alkaline media. The excellent alternatives to the benchmark noble metal‐based HER electrocatalyst are transition metal oxides (TMO). Because of the nontoxicity, cost‐effectiveness, availability, and easy electronic structure tuning, zinc oxide (ZnO) is a good TMO candidate. However, ZnO shows poor performance for HER electrocatalysis and therefore has been much less reported. Herein, it is reported that ZnO can be developed as a good HER electrocatalyst in alkaline media through simultaneously proper cobalt loading at the precursor level (coordination polymer) and defects engineering. The optimum amount of cobalt in ZnO shows an overpotential of 385 mV at 10 mA cm−2 (lower than that of ZnO and Co3O4) and a small Tafel slope of 76 mV dec−1. The introduction of cobalt at the precursor level and subsequently in the wurtzite frame of ZnO as revealed by the analyses, allows to considerably lower the bandgap and increasing the number of defects in the structure, thereby boosting the electrocatalytic performance. This work highlights the potential of cheap and environmentally friendly TMO as alternative HER electrocatalysts for large‐scale alkaline water electrolysis. [ABSTRACT FROM AUTHOR]

The objective of the present study was to examine the synthesized pure and Ce-doped NiO nanoparticles' photocatalytic activity for the degradation of the water pollutant dye Rhodamine B. Firstly these nanoparticles were synthesized using co-precipitation method. X-ray diffraction analysis was used to evaluate the crystallite size and confirmed that synthesized nanoparticles had a single cubic phase. Additionally, various characterization such as UV–vis spectroscopy, Fourier transform infrared spectroscopy, Raman, Scanning electron microscopy, Transmission electron microscopy, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller were done to evaluate band gap energy, functional group, phase identification, morphology, oxidation states of the elements and surface area of the synthesized nanoparticles. The degradation efficiency of Rhodamine B dye was found to be 85.99 % and 94.06 % for pure NiO and Ce-doped NiO nanoparticles respectively. The dielectric properties of said nanoparticles were analyzed, which make these nanoparticles will also be useful in optoelectronics.

Improve optical band gaps of metal oxides by a suitable doping is very interesting for optoelectronic application. However, the effect of doping is usually affected by the synthesis method. Among the existing synthesis routes, coprecipitation is cheap and offers a possibility to strictly control the stoichiometry, depending on the precipitating agents. Herein cobalt doped manganese oxides were prepared via coprecipitation using succinate ion as precipitating agent and their optical properties have been investigated. The results obtained from a set of instrumental techniques revealed that the main phase formed is Mn3O4 hausmatite with cobalt substituting manganese in the structure. The UV–visible diffuse reflectance results demonstrated that the band gap increases from 1.97 for undoped Mn3O4, to 2.91 eV for 5% Co doping, and therefore decreases to 2.34 eV for 6% Co. This trend can be explained by the difference in the substitution site of cobalt which is either tetrahedral or octahedral.

Objective: This study aimed to explore the adsorption performance and mechanism of phenolic acids in simulated sugarcane juice by nano-calcium carbonate modified zeolite (CaCO3@ZL). Methods: Using zeolite as the supporting framework, a co-precipitation technique was utilized to create nano-calcium carbonate modified zeolite (CaCO3@ZL), which was then employed to simulate the adsorption of phenolic acids in sugarcane juice. Using X-ray diffraction (XRD) and infrared spectroscopy (FTIR), the zeolite's characteristics were examined both before and after alteration. The kinetic model fitting of CaCO3@ZL and static adsorption studies were also conducted. The properties of phenolic acids were studied during adsorption. Results: XRD and FTIR characterization results indicate that the modification process successfully prepared nano-calcium carbonate loaded on the surface of zeolite CaCO3@ZL. Comparing the adsorption test results of CaCO3@ZL to those of the unmodified ZL, the adsorption capacity of phenolic acids increased by 40.34%, with adsorption equilibrium at 600 minutes. The fitting results showed that the adsorption process followed the Freundlich isotherm adsorption model and quasi-second-order adsorption kinetics model. After 5 regenerations CaCO3@ZL still maintains 80.39% of the initial adsorption amount of phenolic acid. Conclusion: The adsorption process rate of CaCO3@ZL on simulated sugarcane juice is mainly controlled by multi-molecular layer adsorption and chemical adsorption. CaCO3@ZL has good regeneration performance and can be used for the removal of phenolic acids in sugarcane juice.

Iron oxide nanoparticles are extensively utilized in various fields, particularly in biomedical applications. For such uses, nanoparticles must meet specific criteria, including precise size, morphology, physico-chemical properties, stability, and biocompatibility. Microwave-assisted co-precipitation offers an efficient method for producing water-soluble nanoparticles. Functionalization with citrate during synthesis is crucial for achieving a stable colloidal solution. This study aims to compare the effectiveness of conventional co-precipitation with microwave-assisted co-precipitation. The synthesized nanoparticles were characterized using TEM, DLS, FTIR, XRD, and magnetic measurements. The findings indicate that the in situ citrate functionalization during synthesis results in stable, non-aggregated nanoparticles.

The purpose of the work was to determine the optimal conditions for preparation of chemically pure salts of ammonium orthophosphates based on solutions formed after purification of extractable orthophosphoric acid from toxic impurities of d-metals, lead, arsenic and fluorine by their coprecipitation with calcium hydrogen phosphate. Based on the Sechenov’s modified formula, a method for calculating the solubility polytherms of orthophosphate salts in their mixtures with ammonium chloride was proposed. For its experimental confirmation, studies were conducted to determine the concentrations of saturated solutions of a number of orthophosphate salts in their mixtures with ammonium chloride at temperatures of 14, 40 and 800 C. The results of the calculations were well confirmed by experiments on selective crystallization. It was shown that the following chemically pure products can be obtained from solutions of mixtures of (NH4)2HPO4 and NH4Cl by the methods of isothermal-isohydric crystallization: (NH4)2HPO4 (with a yield of up to 79.5%) and NH4H2PO4 (with a yield of up to 52.4%). Measurements of the concentrations of Cd(II), As(III), Cu(II), Pb(II) and fluorine in the synthesized salts showed that they were at levels lower than the current requirements for maximum permissible concentrations. Therefore, these salts can be recommended for use as food additives. [ABSTRACT FROM AUTHOR]

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