Chemical Co-precipitation Technique Research Articles

Morphological, structural, and electrochemical properties of ZnO- and Ni-doped ZnO nanocrystals formed using different reducing agents in the chemical co-precipitation technique

Morphological, structural, and electrochemical properties of ZnO- and Ni-doped ZnO nanocrystals formed using different reducing agents in the chemical co-precipitation technique

An enhanced electrochemical sensor using ZnO nanoparticles to measure mycophenolate mofetil: A cyclic voltammetric investigation

Zinc oxide nanoparticles (ZnO Nps) were prepared in the current work utilizing a chemical co-precipitation technique with the aim of electrochemically detecting mycophenolate mofetil (MMF). The synthesized nanoparticles showed increased crystallinity with particle diameters of roughly 25.26 nm when analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and EDAX tests. Throughout the research, the physiological pH of 7.4 was kept constant. ZnO Nps-incorporated carbon paste electrode exhibits a significant electroactive surface area (0.0378 cm2), better sensitivity, and consistent current responses as compared to the bare carbon paste electrode (0.0285 cm2). Furthermore, a multitude of additional experiments were carried out, such as sweep rate, concentration, and pH studies, which demonstrated decreased LOD and LOQ, or 0.6 and 1.99 µM, respectively. The modified electrode showed superior stability at 94 % by maintaining its activity. The designed electrode showed a greater recovery of mycophenolate mofetil (MMF) in the 96–98.5 % range, when tested further for an actual sample analysis of MMF in a human urine research.

Degradation of 2,4-dinitrotoluene from aqueous solutions by three-dimensional electro-Fenton with magnetic activated carbon particle electrodes (GAC/Fe3O4)

Abstract 2,4-Dinitrotoluene (2,4-DNT) is a broadly applied nitroaromatic compound with multiple applications, and its simple production has resulted in its extensive utilization in producing explosives, dyes, and rubber. This substance is hazardous and induces genetic mutations in humans, fish, and microorganisms. Thus, this research was done to assess the effectiveness of the three-dimensional electro-Fenton (3D/EF) process employing magnetic activated carbon particle electrodes (GAC/Fe3O4) in eliminating 2,4-dinitrotoluene from water-based solutions. In this experimental investigation, Fe3O4 nanoparticles were created using the chemical co-precipitation technique. The G/β-PbO2 anode was fabricated by electrochemically depositing PbO2 layers on graphite sheets. G/β-PbO2 and stainless steel were utilized as the anode and cathode, respectively. The structure, particle size, and properties of the GAC/Fe3O4 nanocomposite were analyzed using FESEM, XRD, and EDX. The morphology of the G/β-PbO2 electrode was also examined using SEM. The Taguchi experimental design method was employed to identify the optimal conditions. The outcomes demonstrated that higher reaction time and current density, as well as lower pH and pollutant concentration, resulted in improved 3D/EF efficiency. Accordingly, the optimum values of parmeters were identified to be a concentration of 2,4-DNT = 50 mg/L, pH = 3, electrolysis time = 100 min, and current density = 8 mA/cm2. With these parameters, the degradation efficiency of 2,4-DNT through the examined system was 98.42 %, alongside removal efficiencies of 84.69 % for COD and 79.67 % for TOC. Additionally, the results indicated an increase in the average oxidation state (AOS) (from 1.27 to 1.95) and carbon oxidation state (COS) (from 1.27 to 2.75) in the 3D/EF process, along with a decrease in the COD/TOC ratio (from 1.81 to 1.36), indicating the effectiveness of the 3D/EF system in enhancing the biodegradability of 2,4-DNT. Overall, the combined 3D/EF process with a G/β-PbO2 anode has relatively high efficiency in degrading solutions containing DNT and can be considered a viable treatment option for wastewater containing substances such as 2,4-DNT.

A study on the oxidative property using thermogravimetric analysis of NiO nanoparticles prepared by a simple wet chemical method

Nanosized NiO particles were synthesised by chemical co-precipitation technique and the particle has been characterized morphologically, elementally, structurally and thermally using High Resolution Scanning Electron Microscopy (HR-SEM), Energy Dispersive X-ray Spectroscopy (EDAX), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Thermogravimetric Analysis (TGA). A green precipitated Nickel Oxide Nanoparticles (NiO NPs) was prepared and the size of the particle was found to be 45 nm and the presence of Ni and O elements were confirmed using the elemental analytic tools like EDX and FTIR in which the existence of water molecules was confirmed from the absorption spectrum. The generated sample's crystal structure was face-centered cubic, and Scherer's equation was used to compute its size, which was found to be 43 nm. Crystal characteristics including crystal parameters (a), interatomic distance (dh,k,l), atomic radius (r) and cell volume (Vc) were also calculated. The weight loss observed from TGA curve signifies the oxidative property of NiO NPs and there is a steady increase in the weight difference versus time difference. The calcination temperature of NiO was determined to be 700⁰C via analysis at the TGA curve's peaks. The activation energy (Ea) was determined using Coats-Redfern method by solving the slope of the graph between log[−log(1−α)T2] and 1000T. With respect to its highly effective capacity, which can be seen when treating with an increase in temperature, NiO may be used as an oxidising and reducing agent in oxidation and reduction processes.

Photocatalytic Degradation of Methylene Blue Dye by Using Different Nanoparticles

Zinc sulfide nanoparticles (NPs) were produced through a straightforward and cost-efficient chemical co-precipitation technique, intended for use in the photocatalytic decomposition of methylene blue (MB) dye, both under ultraviolet and visible light exposure. To evaluate the synthesized nanoparticles, various analytical tools including ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffractometry (XRD) were employed. The XRD analysis confirmed the cubic symmetry of the synthesized NPs. SEM analysis revealed that the nanoparticles tend to aggregate, forming clusters of nanoparticles. TEM analysis illustrated that the ZnS nanoparticles exhibit a spherical morphology with uniform size distribution. Additionally, Fourier-transform infrared (FTIR) analysis exhibited a vibrational peak at 616 cm-1. The degradation of methyl blue was investigated using a UV-Vis spectrophotometer as part of the study.

Flexible supercapacitors based on carbon fiber cloth coated copper hexacyanoferrate nanoparticles as positive electrode material

Herein, we report fabrication of a new electrode material based on copper(II) hexacyanoferrate(II) nanoparticles coated on flexible and light weight carbon fiber cloth (CuHCF-NPs@CC) for supercapacitors application. Uniform spherical CuHCF-NPs are successfully synthesized through a simple chemical co-precipitation technique at ambient temperature. The CuHCF-NPs were physically examined by different characterizations, for example, FT-IR, UV–Visible, Raman, XRD, XPS, FE-SEM, EDAX and TEM. The CuHCF-NPs@CC is an excellent electrode material that has an open framework structure that can accommodate a wide variety of ions. The electrochemical characteristics of pseudocapacitive behavior of the material were characterized by cyclic voltammogram (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) on two different electrolytes such as K2SO4 and Na2SO4. The CuHCF-NPs@CC exhibits a good reversible cycle in the range of 0 to 0.9 V and excellent charge-discharge performance with a specific capacity of 42.96C g−1 and 24.2C g−1 at 0.2 A g−1 of current density in K2SO4 and Na2SO4 electrolyte, respectively. The low cost, simple preparation methodology, and an outstanding electrochemical behavior of CuHCF-NPs@CC considering a viable candidate for the future energy storage system.

Effect of Ti3C2Tx MXenes on the structure, morphology, fluorescence and temperature-sensitive properties of Eu3+-doped (YSZ)0.3-(YTaO4)0.7 rare-earth high-temperature ceramic powders

The rapid development of rare-earth fluorescent materials based on the fluorescence intensity ratio method allows the monitoring of internal temperature, stability and service life of thermal barrier coatings (TBCs). In this paper, Eu3+ doped (YSZ)0.3-(YTaO4)0.7 rare-earth ceramic materials was firstly prepared by chemical co-precipitation technique, and the doping content of Eu3+ was optimized by comparing its effect on morphology, luminescence and temperature sensitive performance of (YSZ)0.3-(YTaO4)0.7. Then the Ti3C2Tx MXene was subsequently blended into the optimal (YSZ)0.3-(YTaO4)0.7: Eu3+ powders by mechanical milling. The influence of Ti3C2Tx MXenes on the structure, morphology, fluorescence properties and temperature sensitivity of (YSZ)0.3-(YTaO4)0.7: Eu3+ powders was further investigated systematically. Results showed that (YSZ)0.3-(YTaO4)0.7: Eu3+ powders were compound of M′-YTaO4 and YSZ in tetragonal phase. The optimal doping content of Eu3+ is 1.5 mol%. The adding of Ti3C2Tx MXene did not affect the structure of (YSZ)0.3-(YTaO4)0.7:Eu3+ powders. After addition of Ti3C2Tx MXenes, part of (YSZ)0.3-(YTaO4)0.7:Eu3+ particles embedded in the middle of the accordion-shaped MXenes sheet, while the other part wrapped around MXenes. Ti3C2Tx MXenes could significantly improve the luminescence intensity, fluorescence lifetime and temperature-sensitive performance of (YSZ)0.3-(YTaO4)0.7: Eu3+powders. The optimal addition amount of Ti3C2Tx MXenes is 0.6 wt%. The absolute and relative sensitivities of MXene/(YSZ)0.3-(YTaO4)0.7:Eu3+ powders archived 2 times of (YSZ)0.3-(YTaO4)0.7: Eu3+ powders. Therefore, MXene/(YSZ)0.3-(YTaO4)0.7: Eu3+ could be used as temperature-indicating ceramic materials with highly efficient fluorescent properties for real-time monitoring of internal temperature of TBCs.

Structural, optical, magnetic properties and energy-band structure of MFe2O4 (M = Co, Fe, Mn) nanoferrites prepared by co-precipitation technique.

MFe2O4 (M = Co, Fe, Mn) nanoparticles were successfully formed through the chemical co-precipitation technique. X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analysis were used to investigate samples' structural properties. The investigated structural properties included phases formed, crystallite size, cation distribution, hopping length, bond length, bond angle, edge length, and shared and unshared octahedral edge length. Scanning electron micrographs of the prepared samples demonstrated well-defined crystalline nanoparticles. The grain diameter was 15, 9, and 34 nm for CoFe2O4, Fe3O4, and MnFe2O4, respectively. The energy-dispersive X-ray analysis confirmed the existence of every element (Co, Fe, and O) and no discernible impurities in the samples. The optical properties were studied in detail through photoluminescence (PL) spectroscopy and Raman spectroscopy. The presence of active modes in Raman spectra confirmed the spinel structure of the MFe2O4 nanoparticles. The direct bandgap energy estimated through UV-visible spectroscopy was about 2.59-2.64 eV, corresponding with the energy-band structures of the octahedral site (1.70 eV) and the tetrahedral site (0.9 eV). This result was further confirmed by PL emission spectra. Based on Mie theory and UV-visible and PL spectral data, the mechanism of photothermal characterization for MFe2O4 nanoparticles was determined. Investigating the changes in temperature of magnetic parameters including coercivity, squareness ratio, and saturation magnetization for MFe2O4 samples showed the dominant influence of ion distribution and A-A, A-B, and B-B exchange interactions. This study also showed that strong anisotropy and weak dipolar interaction tended to increase the coercivity and squareness ratio of CoFe2O4. Conversely, weaker anisotropy and stronger dipolar interaction corresponded with the small coercivity and squareness ratio of Fe3O4 and MnFe2O4 samples.

Fabrication of rare-earth cerium-doped nickel-copper ferrite as a promising photo-catalyst for congo red-containing wastewater treatment.

Synthetic organic dyes are becoming the major class of water pollutants leading to malignant detriments to the ecology. Consequently, this research focuses on remediating this circumstance utilizing a novel catalytic material, namely, cerium-doped spinel ferrite Ni0.6Cu0.4Ce x Fe2-x O4 (x = 0.0, 0.5, 1.0, 1.5), developed using the chemical coprecipitation technique and characterized using FTIR, XRD, FE-SEM, EDX and VSM analysis. The particles have shown band gap values ranging from 4.29 to 2.01 eV. The as-synthesized nano-sized particles were employed as a photocatalyst to degrade the complex structure of congo red (CR) dye. About 91% of the dye was degraded with 60 mg of the catalyst under visible light irradiation with the highest cerium-doping (x = 1.5) at a pH below 6.8, which was the zero-surface charge pH for the particle. Batch studies were performed to optimize all the conditions, including the dose, concentration, pH, and different light energy sources. Recyclability of the catalyst was also investigated, which was supported by the higher stability of the recovered particles through XRD analysis. Reaction kinetics for this system were evaluated along with three isotherm models. Moreover, the scavenging test indicated that the major active species leading to this degradation was hole (h+), and a schematic degradation mechanism is presented. Following that, this model can successfully be used for wastewater treatment.

Synthesis of surfactant-assisted nickel ferrite nanoparticles (NFNPs@surfactant) to amplify their application as an advanced electrode material for high-performance supercapacitors.

Nickel ferrite nanoparticles (NFNPs) were synthesized in an alkaline medium (pH ∼ 11) using a wet chemical co-precipitation technique. To probe the effect of surfactants on the surface morphology, particle size and size distribution of nanoparticles; two surfactants, namely, cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulphate (SDS), were applied. The native and surfactant-assisted nickel ferrite NPs were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and transmission electron microscopy (TEM). The addition of surfactants (CTAB/SDS) effectively controlled the secondary growth of nickel ferrite particles and reduced their size, as examined by XRD, AFM, DLS, SEM and TEM. Characterization technique results affirmed that CTAB is a more optimistic surfactant to control the clustering, dispersion and particle size (∼22 nm) of NFNPs. To identify the impact of ferrite particle size on charge storage devices, their electrochemical properties were studied by using cyclic voltammetry (CV), galvanic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) in 1 M KOH electrolyte through three-electrode assembly. NiFe2O4@CTAB showed a specific capacity of 267.1 C g-1, specific capacitance of 593.6 F g-1 and energy density of 16.69 W h kg-1, which was far better than the performances of other synthesized native NFNPs and NiFe2O4@SDS having larger surface areas.

In diabetic male Wistar rats, quercetin-conjugated superparamagnetic iron oxide nanoparticles have an effect on the SIRT1/p66Shc-mediated pathway related to cognitive impairment

BackgroundQuercetin (QC) possesses a variety of health-promoting effects in pure and in conjugation with nanoparticles. Since the mRNA-SIRT1/p66Shc pathway and microRNAs (miRNAs) are implicated in the oxidative process, we aimed to compare the effects of QC and QC-conjugated superparamagnetic iron oxide nanoparticles (QCSPIONs) on this pathway.MethodsThrough the use of the chemical coprecipitation technique (CPT), SPIONs were synthesized, coated with dextran, and conjugated with quercetin. Adult male Wistar rats were given intraperitoneal injections of streptozotocin to look for signs of type 1 diabetes (T1D). The animals were randomized into five groups: the control group got deionized water (DI), free QC solution (25 mg/kg), SPIONs (25 mg/kg), and QCSPIONs (25 mg/kg), and all groups received repeat doses administered orally over 35 days. Real-time quantitative PCR was used to assess the levels of miR-34a, let-7a-p5, SIRT1, p66Shc, CASP3, and PARP1 expression in the hippocampus of diabetic rats.ResultsIn silico investigations identified p66Shc, CASP3, and PARP1 as targets of let-7a-5p and miR-34a as possible regulators of SIRT1 genes. The outcomes demonstrated that diabetes elevated miR-34a, p66Shc, CASP3, and PARP1 and downregulated let-7a-5p and SIRT1 expression. In contrast to the diabetic group, QCSPIONs boosted let-7a-5p expression levels and consequently lowered p66Shc, CASP3, and PARP1 expression levels. QCSPIONs also reduced miR-34a expression, which led to an upsurge in SIRT1 expression.ConclusionOur results suggest that QCSPIONs can regulate the SIRT1/p66Shc-mediated signaling pathway and can be considered a promising candidate for ameliorating the complications of diabetes.

A novel nickel-doped photoactive nanocomposite materials for the application of wastewater treatment

We have reported an efficient and novel nanocomposite structure of nickel (0.5 %, 1.0 %, 1.5 %, 2.0 % and 2.5 %) doped Fe3O4@rGO which is prepared by a simple chemical co-precipitation technique for degradation of methylene blue. In the current study, reduced graphene oxide (rGO) is chosen as the electron mediator for NiFe3O4/rGO nanocomposite catalyst to construct a binary photocatalytic system. The analysis of structural and optical properties supports their nano size, formation of nanocomposite material, doping of nickel ions into the characteristic inverse spinel cubic structure of Fe3O4 and the existence of synergistic effect between NiFe3O4 and rGO. Methylene blue was considered as a model dye during the investigation of the Photocatalytic activity of NiFe3O4/rGO. From the kinetic measurements, the reaction rate was predicted to play a key role in the process of degradation. This discussion also highlights the absorption peak extension towards the visible region and the energy band gap value decreases with increasing the nickel dopant concentration in novel NiFe3O4/rGO nanocomposite material. Transition metal doping significantly enhances the degradation efficiency and reduces the recombination rate of charge carriers which makes the NiFe3O4/rGO nanocomposite material a potential candidate for the degradation of methylene blue from wastewater. As indicated by all the nanocomposites, photocatalytic activity was higher than the pure Fe3O4 photocatalyst, and the highest photodegradation of 96.3 % MB within 30 min irradiation under visible light was shown by the 2.0 % of nickel-doped Fe3O4@rGO. In addition, the study examined the photodegradation process and photocatalytic reaction kinetics of MB.

Preparation, characterization, and in vitro evaluation of the anticancer activity of Ce3+ doped CuFe2O4 spinel nanoparticles in MCF-7 cell lines

In the present study, we successfully prepared nanoparticles of Ce-doped Copper ferrite, CuCexFe2-xO4(x = 0.00, 0.03, and 0.05), in the nanoscale using the chemical co-precipitation technique. The structure, composition, optical properties, and morphological information of the obtained ferrite nanoparticles (NPs) were analyzed by making use of powder X-ray diffraction (PXRD) pattern, Field Emission Scanning Electron Microscopic (FE-SEM) studies, Fourier Transform Infrared Spectroscopic (FT-IR) analysis, and Energy-dispersive X-Ray Spectroscopy (EDS), and the UV–Vis-NIR Spectroscopy. The cytotoxicity of CuCexFe2-xO4 nanoparticles (NPs) on the MCF-7 breast cancer cell line was evaluated using the MTT assay. The NPs exhibited dose-dependent cytotoxicity, with lower concentrations (<25 µg/mL) being safe and biocompatible, while higher concentrations reduced cell viability and disrupted L929 fibroblast cell lines. Double staining and flow cytometry experiments revealed that apoptosis is one of the mechanisms by which CuCexFe2-xO4 NPs induce cytotoxicity in MCF-7 cells. An increase in reactive oxygen species (ROS) was found in the presence NPs. To harness the full potential of this nanoparticle formulation, it is recommended that future investigations encompass a wide range of in vitro and in vivo models. These subsequent studies will significantly contribute to the expanding body of knowledge concerning the synthesis of composite nanoparticle formulations for use as anticancer agents.

Modified matrix of ZnO prismoid structures for improved photocatalytic activity: A theoretical and experimental insight

Currently, the world needs low-cost and high-performance photocatalysts to degrade the carcinogenic pollutant from water. In the present work, a modified ZnO matrix using Mg as a dopant has been reported with theoretical and experimental results to highlight its structure and functions on photocatalytic activity. A versatile chemical co-precipitation technique was employed to get the Mg-ZnO nanostructures. Structural characterization by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) studies show the formation of hexagonal wurtzite structures with no impurity phases. Optical studies confirm the formation of ZnO with intrinsic defects after modifying the matrix, which agrees with the band structure calculations computed using density functional theory (DFT). Mg-modified ZnO introduced intrinsic defects like vacancies and interstitials that have a great impact on applications like photocatalysis. Based on these supporting results we employed prepared samples for dye degradation, which performed well (80% degradation efficiency) in a short period of UV irradiation. This could be a promising technology for environmental remediation.

Optical and Color Investigation of the Effect of Laser Radiation on Polyaniline/Polyvinyl Pyrrolidone/Zinc Sulfide Nanocomposite Films

A nanocomposite (NC) of polyaniline (Pani), polyvinyl pyrrolidone (PVP) and zinc sulfide (ZnS) nanoparticles (NP) was prepared using chemical coprecipitation and ex-situ casting procedures. ZnS NP were synthesized using the chemical coprecipitation technique in atmospheric air. The x-ray diffraction (XRD) scans indicated that the synthesized ZnS had a nanonature and fit the cubic zinc blended structure. We used an infrared pulsed laser to irradiate the Pani/PVP/ZnS NC samples with fluences ranging from 3 to18 J/cm2. The induced changes in the NC were investigated using the UV spectroscopy and International Commission on Illumination (CIE) color difference methodology. When the laser fluence increased up to 18 J/cm2 both the direct and indirect optical bandgaps (Eg) decreased. Additionally, we used the optical dielectric loss (ε”) to detect the type of microelectronic transition for the NC samples. The Eg of the exposed NC samples and the pristine samples exhibited indirect allowed transitions. The laser effects on the absorbance, extinction coefficient, transmission, refractive index, dielectric parameters and optical conductivity of the NC were studied. Lastly, the color differences between the pristine and exposed samples were determined. The pristine Pani/PVP/ZnS showed a significant color difference with the laser irradiated samples. The changes of the studied optical parameters with the laser fluence indicated that the laser radiation represents a convenient tool that would allow the application of Pani/PVP/ZnS NC in optoelectronic devices.

Cytotoxicity and uptake analysis of Mn-Zn ferrite-based temperature-sensitive ferrofluid on cervical and bone cancer cells

The present study reports synthesise, characterization, and evaluation of Mn-Zn ferrofluid's magnetic and essential biocompatible properties for its plausible utilization in magnetic fluid hyperthermia. Lauric acid-coated Mn0.8Zn0.2Fe2O4 (A82) magnetic fluid (MF) was synthesized by a chemical co-precipitation technique, revealing a crystalline size of 11.7 ± 0.5 nm and displaying superparamagnetic behaviour. MF at and above 0.8 mg/mL concentration in cell culture media reached a hyperthermic temperature of 42 ℃ within 30–40 min when exposed to a 332 kHz frequency and 12.5 kA/m magnetic field. In vitro experiments revealed that the MNPs at this concentration were cytotoxic. Subsequently, a non-toxic 0.5 mg/mL A82 was used that efficiently internalized into the cytoplasm of cancer cell lines HeLa and MG-63 in 24 h. These results suggest that A82 can be a promising candidate for its plausible use in biomedical (magnetic fluid hyperthermia) and tissue engineering applications.

Structural and optical integrity of pure and NiFe2O4-GO nanoferrite: A combined experimental and first principles approach

Graphene oxide (GO)-supported nickel ferrite (NiFe2O4) nanoparticles were prepared via the chemical co-precipitation technique. The resulting pure NiFe2O4 and NiFe2O4/GO nanocomposites display an inverse cubic spinel structure with binary interstice occupancy according to experimental and density functional theory (DFT) simulations. The structural-dependent physiochemical variations reflect in the narrow bandgap of GO-coupled NiFe2O4 with a distinct structural landscape. The narrow optical bandgap of the resultant GO-NiFe2O4 (1.48 eV) nanoferrite illustrates their potential utility as a promising photocatalyst with active charge separation.

Optical, photo catalytic, electrochemical and antibacterial performance of ZnO and Co doped ZnO nanoparticles

The present work designates the preparation of pure ZnO and Cobalt doped ZnO nanoparticle with the general formula Zn1-xCoxO (x = 0.00, 0.01, 0.03, 0.05) by wet Chemical Co-precipitation technique. The prepared nanoparticles were characterized by XRD, FTIR, SEM with EDAX, UV-DRS and Photoluminescence spectroscopy. XRD outcomes confirmed that these nanoparticles exhibited hexagonal wurtzite structure of ZnO lacking any secondary phase. The crystallite size of the formed products was calculated by Scherrer’s formula. The calculated average crystallite size decreased from 10 to 28 nm (x = 0.00 to 0.05). Through SEM analysis the shape and morphology of the sample was determined, which showed wurtzite structures with irregular dimensions. UV–Vis DRS spectral studies indicated a decrease in the band gap with an increase in doping concentration. Photoluminescence studies exhibited a green emission peak at 521 nm. Additionally, photodegradation of these nanoparticles was evaluated through degradation of MB dye. Synthesized nanoparticles illustrates appreciable electrochemical performance, pH shows nearest to Nernst value, MCPE is adsorption controlled and LOD of PA is very low compared to another modified electrode. Pure ZnO and Co-ZnO were examined against gram-positive Enterococcus faecalis and gram-negative Escherichia coli bacteria and it was found that the anti-bacterial activity improved with Cobalt doping compared to the pure ZnO nanoparticles.

Electrical conductivity of (Ni,Mn,Fe,Cu)3O4 ceramic semiconductors designed for temperature and magnetic field sensing

This research is focused on designing new ceramic oxides with the spinel structure for a potential application as sensitive temperature and magnetic field sensors. In this respect, the mixtures of ferrimagnetic NiFe2O4 with low-resistive Ni0.66Cu0.41Mn1.93O4 semiconductor (molar coefficient α=1/5 and 1/2) were prepared using the chemical co-precipitation technique followed by a low-temperature sintering of the cold-pressed powders. For the prepared materials, a variation of the electrical conductivity σdc with temperature T (in the range 50 K–400 K) is quantitatively analyzed using different theoretical concepts of the charge carrier hopping transport occurring in disordered materials with strong electron-phonon interaction. It has been shown that an increase in α from 0 to 1/2 causes a step-like change of the dc electrical conductivity and, simultaneously, a gradual change in the magnetization M determined in the saturation state. The temperature coefficient of resistance TCR of the prepared ceramics takes the values from −0.6%/K (at 400 K) to −19.6%/K (below 100 K). The highest absolute value of the magneto-resistance coefficient MR determined at 150 K (and at magnetic field 7 T) registered for ceramic oxide with α=1/2 was found to be 3.4%.

Chromium and copper dual-doped zinc sulfide nanoparticles: Synthesis, structural, morphological and optical properties

Copper (Cu) and chromium (Cr) dual-doped zinc sulfide (ZnS) nanoparticles (NPs) were fabricated via a chemical co-precipitation technique at 24±°C without any capping agent used. The obtained metal sulfides were characterize using transmission electron microscope (TEM), scanning electron microscope (SEM),energy-dispersive X-ray (EDX), X-ray diffraction (XRD), ultra-violet/visible (UV–Vis), and thermogravimetric analysis (TGA). The results revealed a Cr, Cu in ZnS lattice, grain size less than 5 nm, and unequal, aggregated spherical particles. Moreover, XRD analyses indicated that the dual ions penetrated the zinc sulfide without changing its cubic structure, the average size was nearly in the range 2.035–1.959 nm. Optical analysis displayed blue-shift after doping. The band gap values(Eg) were in the range of 4.79–4.89 eV. Thermal analysis shows that the synthesized sample is more stable in range 434–1029 °C. Based on these featured, it could be concluded that the synthesized Cu and Cr dual-doped ZnS NPs are beneficial for opto-electronic devices, and photocatalytic applications.