Zinc Manganite Research Articles

Modulating optical and electrical properties of chemically synthesized ZnMn2O4 nanoparticles through crystallinity: Integrating theoretical and experimental insights

Theoretical and experimental analyses of zinc manganite (ZnMn2O4) nanoparticles were carefully conducted for in-depth exploration of their electronic and optical properties. Nanosized particles, approximately 11–15 nm in size, were synthesized using a post-sintering assisted co-precipitation method. Theoretical calculations using Rietveld refinement were conducted to accurately predict crystal parameters and simulate XRD patterns consistent with experimental XRD observations. UV–visible absorption spectra and Tauc plot analysis indicated a bandgap ranging from 0.65 to 0.79 eV, while photoluminescence spectra revealed the most intense peak at 466 nm, possibly arising from exciton recombination processes or defect-related emissions. Density function theory (DFT) calculations were employed to compute the band structure and density of states of ZnMn2O4, resulting in a calculated bandgap of 0.73 eV, which aligned closely with the experimental findings. Moreover, DFT calculation identified atomic-level transitions responsible for absorption peaks in the material. Comprehensive evaluations of the mechanical and optical properties, integrating theoretical insights with experimental data, provided a holistic understanding of the intricate electronic and optical characteristics of ZnMn2O4. Furthermore, frequency and temperature-dependent dielectric properties demonstrated the MWS-type polarization effect. Besides, the activation energy of 0.582–0.553 eV, calculated using the Arrhenius plot, was good in accordance with our dielectric analysis, solidifying the potential of this nanomaterial for advanced optoelectronic applications.

Fabrication, microstructure and hemostatic activity of Cu-Zn manganite nanoparticles

Copper subbed zinc manganite Zn(1-x)CuxMn2O4 (x = 0.05,0.15,0.25,0.35,0.45,0.55) (BCZMO) NPs were prepared by sol–gel co-precipitation technique at surrounding temperature. BCZMO NPs were analyzed by XRD, SEMfor microstructure characterizations. XRD study confirms the tetragon structure of BCZMO NPs and effect of copper on ZMO NPs. SEM micrographs supports our findings. The BCZMO NPs interfered in blood coagulation and exhibited pro-coagulant property. BCZMO NPs decreased the coagulation time of citrated plasma from control 4.31 min to 1.35 min. In addition, the BCZMO NPs aggregated platelets up to 80 % at a concentration of 600 µg while the agonist epinephrine prompted platelet collection of around 90 % at 10 mM concentration.No kind of hemolytic activity in RBC cells shown by these BCZMO-NPs insisting their non-toxic nature. These BCZMO-NPs exhibited pro-coagulant effect with their interference in blood coagulation cascade and initiation in platelet aggregation. Thus, BCZMO NPs can be a potential candidate in biomedical field as hemostatic agents.

Mn-deficient ZnMn2O4/Zn0.5Mn0.5Fe2O4 cathode for enhancing structural reversibility and stability of zinc-ion batteries

Aqueous zinc-ion batteries have surfaced as a viable energy storage technology due to their safety, eco-friendliness, and cost-effectiveness. Binary zinc manganite oxide (ZnMn2O4 or ZMO) stands out as the potential cathode material owing to its considerable theoretical capacity and high operating voltage. However, high electrostatic repulsion of Zn2+ ions within ZMO leads to sluggish diffusion and poor reversibility of Zn2+ ions insertion/extraction that can reduce charge storage and overall cycling performance. This study addresses this challenge by introducing FeCl3 during the synthesis to form ZMO/Zn0.5Mn0.5Fe2O4 (ZMFO) cathode material. This cathode features Mn-deficient structures, which can reduce the electrostatic repulsion via low Mn occupancies and lattice parameters enlargement, thus facilitating Zn2+ ions diffusion. Ex-situ X-ray diffraction analyses further show that the cathode is able to maintain good structural reversibility during the charge-discharge cycles. Additionally, the ZMO/ZMFO cathode exhibits smaller particle sizes than pristine ZMO, providing a wider surface area. The presence of ZMFO with a large unit cell volume can also enhance Zn storage capacity and accelerate Zn2+ ions kinetics. Highlighting those advantages, aqueous zinc-ion batteries with ZMO/ZMFO cathode show a capacity of ~230 mAh g−1 at 0.05 A g−1 and retain 99 % of its initial capacity at 0.2 A g−1 after 200 cycles of charge-discharge.

Enhanced bifunctional water electrolysis performance of spherical ZnMn2O4 nanoparticles

Spinel-type transition metal oxide-based catalysts are crucial for efficient electrocatalytic oxygen and hydrogen generation. Therefore, in this study, zinc manganite (ZnMn2O4) nanostructures were synthesized using two different reducing agents, including sodium carbonate (Na2CO3) and sodium hydroxide (NaOH), through the coprecipitation method. When ZnMn2O4 was synthesized using NaOH, the sample exhibited a morphology with the aggregated and stacked nanobundles. In contrast, the Na2CO3-derived ZnMn2O4 sample demonstrated an interconnected and agglomerated spherical nanoparticle structure. For the oxygen evolution reaction, the spherical ZnMn2O4 nanoparticles exhibited the exceptional electrocatalytic performances, with an overpotential of 110 mV and a low Tafel slope of 47 mV/dec, showing excellent durability at 10 mA/cm2 in an alkaline electrolyte. For the hydrogen evolution reaction, the spherical ZnMn2O4 nanoparticles indicated a low overpotential of 158 mV and a Tafel slope of 120 mV/dec, with excellent stability at −10 mA/cm2. These findings suggest that the spherical ZnMn2O4 nanoparticles are effective electrocatalysts for highly efficient water-splitting.

Zinc manganite as an efficient battery-grade material for supercapattery devices

In the current context, supercapatteries emerge as highly desirable candidates capable of merging both energy and power density within a single device. Battery-type metal oxide materials, combined with capacitive-based materials, stand out as promising candidates for high-performance supercapatteries. This investigation centers on the synthesis of nanocrystalline ZnMn2O4 (ZMO) and CoMn2O4 (CMO) through a straightforward hydrothermal method, followed by their physico-electrochemical characterization. Electrochemical analysis reveals that ZMO exhibits notably enhanced charge storage capability compared to CMO. This superiority can be attributed to favourable electro-structural properties, and stable redox chemistry of ZMO. The real-time performance of ZnMn2O4 was further assessed by fabricating a hybrid asymmetric supercapattery device (ZnMn2O4||NrGO), which achieves a specific capacity of 232 C g−1 at a current density of 1 A g−1. The hybrid asymmetric device underwent rigorous stability testing for 4000 cycles at a current density of 2 A g−1, showcasing remarkable performance with a 92 % retention of its initial capacity. The device demonstrated a power density of 980 W kg−1 and an energy density of 63 Wh kg−1, highlighting its considerable promise in the field.

Influence of Zinc Manganite Nano Fillers on the Optical and Dielectric Features of Poly-Methyl Methacrylate/Multi-Walled Carbon Nanotubes Nanocomposites

Poly (methyl methacrylate, PMMA)/ multi-walled carbon nanotubes (MWCNTs)/ x wt %zinc manganite (ZnMn2O4) polymers were fabricated using co-precipitation and casting techniques. The structure of the filler and all polymers was determined with X-ray diffraction. The morphology of the polymer surfaces was explored by employing scanning electron microscopy. The direct and indirect band gap energies (E g) of PMMA polymer (5.02, 4.44) eV decreased attaining minimum values (4.97, 3.41) eV upon the addition of MWCNTs and 2 wt% ZnMn2O4. The refractive index at 600 nm was increased from 1.33 (PMMA) to 1.55 (x = 2 wt% ZnMn2O4). The optical dielectric constant and optical conductivity displayed their highest values when the ZnMn2O4 doping level reached 2 wt%. The PMMA/MWCNTs/x wt% ZnMn2O4 polymers exhibited blue-violet colors on the CIE 1931 chromaticity diagram under excitation wavelength of 317 nm. The electrical dielectric constant and the AC conductivity attained their peak at the concentration of 2 wt% and 1 wt% ZnMn2O4, respectively. PMMA/MWCNTs/x wt% ZnMn2O4 polymers possess controllable optical and electrical characteristics, thus making them potentially valuable optical materials for future optoelectronic or photocatalytic application development.

Optical, thermal, mechanical, and antibacterial properties of polyvinyl alcohol/sodium alginate/ZnMn2O4 nanocomposites films for various optical devices and food packaging applications

This work involves preparing zinc manganite nanoparticles (ZnMn2O4 NPs) using the Sol-gel method. Polymer nanocomposites of polyvinyl alcohol (PVA)/Sodium alginate (NaAlg)- ZnMn2O4 NPs were created using the solution casting technique. The polymer nanocomposites films were made with varying weight percentages of ZnMn2O4 nanoparticles. With the addition of nanofiller, the reduced direct and indirect energy band gap values and increased Urbach energy values were discovered in the UV–Vis data. XRD data showed a reduction in crystallinity degree with dopant. ZnMn2O4 NPs had a strong interaction with PVA/NaAlg blend, as confirmed by FTIR. The addition of ZnMn2O4 NPs led to improved thermal stability of the polymer nanocomposites films. Additionally, the nanocomposites films' mechanical characteristics were examined. The loading of ZnMn2O4 nanoparticles has been associated with an increasing trend in the mechanical properties of the nanocomposites, including its toughness, Young's modulus, Tensile strength (Ts), and elongation. The antibacterial activity of the nanocomposites against fungus and bacteria was studied. Additionally, PVA/NaAlg-ZnMn2O4 nanocomposites films had good antibacterial characteristics against environmental microorganisms such as Gram-positive (G+) S. aureus and Gram-negative(G−) E. coli bacteria as well as fungi C. albicans and A. niger. It was observed that the biodegradability of the nanocomposite films was lower compared to the pure PVA/NaAlg film. Compared to pure film, the water solubility was decreased upon the addition of ZnMn2O4 NPs. After ZnMn2O4 was added to the pure blend, the WVTR decreased. The produced polymer nanocomposites films appear to be a promising material for food packing, according to these results.

Zinc-ion battery with non-aqueous electrolyte and zinc-manganese spinel positive electrode

Zinc manganite spinel powder specific surface area was found to increase by an order of magnitude via a treatment with sulfuric acid. The specific surface area, determined by nitrogen adsorption, correlates with the specific capacity of zinc manganite spinel positive electrodes. Zinc manganite spinel subjected to a controllable acidic treatment is a promising material for the non-aqueous zinc-ion batteries.

Frequency-influenced dielectric analysis of sol-gel assisted Mg2+ substituted ZnMn2O4 nanoparticles

This study deals with the effect of Mg2+ doping on the structural, optical, and dielectric properties of zinc manganite nanoparticles. A series of MgxZn1-xMn2O4 (x = 0–0.5) samples were prepared with an auto-combustion synthesis method. Rietveld refinement of XRD revealed a pure tetragonal inverse spinel phase, supported by FTIR spectral analysis. Morphological studies indicated the transformation of micro-spherical to rod-like shapes for doped samples. With increased dopant concentration, the three Raman active modes shift towards higher frequencies. The co-existence of Mn2+, Mn3+, and Mn4+ states was revealed by chemical state analysis. The MZMO-5 sample exhibited the smallest energy bandgap (∼1.64 eV). The refractive indices of these samples were estimated to be ∼ 0.4 which might be useful for switching and filter circuits. These nano-manganite samples exhibited high dielectric constants and low losses, indicating their potential use in communication devices.

Influence of Al Doping on the Structural, Optical, and Electrical Characteristics of ZnMn2O4

Doped zinc manganite samples were synthesized using the sol-gel method, incorporating varying amounts of aluminum (ZnMn2-xAlxO4, x = 0, 0.03, 0.05, 0.07, 0.1). High quality X-ray diffraction data enabled detection and accurate quantification of the predominant phase ZnMn2O4 (ZMO) and minor phase ZnO. The structure and microstructure of developed phases were investigated applying the Rietveld refinement method. The nanoscale nature of the samples was examined by High-resolution transmission electron microscopy (HRTEM); the incorporation of Al into the ZMO matrix and the oxidation states of various cations were studied through X-ray photoelectron spectroscopy (XPS). The introduction of Al has resulted in a modification of the light-absorption characteristics of the ZMO sample. Specifically, the direct optical band gap energy of ZMO decreased from 2.45 to 2.25 eV with an increase in the amount of Al doping to 0.1. Moreover, an investigation was conducted into the impact of Al doping amount, frequency, and temperature on the dielectric constant, dielectric tangent loss, ac conductivity, complex impedance, and complex electric modulus. It was observed that all samples, except for the sample with x = 0.05, exhibited ferroelectric features. The activation energies for the samples with x = 0, 0.03, 0.05, 0.07, and 0.1 were determined to be 0.274, 0.456, 0.099, 0.103, and 0.152 eV, respectively. The conduction mechanism type in the different samples was identified. The obtained changes of dielectric properties indicated the capability of improving the ZMO characteristics for various applications via controlling the doping content of Al.

Facile chemical synthesis of mixed Zn-Co manganite based tetragonal spinels for energy storage and environmental remediation

In this study, the mixed Zn-Co manganite based spinels Zn1−xCoxMn2O4 (where x = 0, 0.05, 0.10, 0.15, 0.20, and 0.25) were prepared by the chemical co-precipitation route. The fabricated Co-doped ZnMn2O4 spinels were characterized by XRD, SEM, FT-IR, EDAX, BET, TEM, and UV–vis spectroscopy techniques. The XRD studies detailed the crystal-structure of body-centered tetragonal zinc manganite spinels. EDAX analysis showed the existence of pure phase elements, and the atomic-weight percentages of elements closely match with those present in the respective precursors. The BET surface areas of ZM P and ZCM 5 samples were found to be 22.52 and 36.76 m2/g, respectively. The metal-oxygen bonds of the zinc manganite spinel materials were appeared at 518 and 638 cm−1. The interplanar distance of 0.28 and 0.46 nm, assigned to the (200) and (112) crystal planes of ZnMn2O4, respectively. The band gap energies of the samples decreased from 3.3 to 3.22 eV with increased dopant concentration. The photodegradation efficiency of prepared samples was evaluated by Rhodamine 6G dye under UV illumination. The electrochemical properties were examined by CV, GCD, and EIS. The experimental observations exhibited that the fabricated Co-doped ZnMn2O4 sample (ZCM 5) showed greater photocatalytic activity (87 % after 120 min) and outstanding electrochemical performance (486 F g−1) than undoped ZnMn2O4 (ZM P) material. ZCM 5 electrode material demonstrated excellent cycling life, with 88 % capacitance retention after performing for 1000 cycles.

Thermodynamics and Electrophysics of New LaCaCuZnMnO6 Copper–Zinc Manganite of Lanthanum and Calcium

Thermodynamics and Electrophysics of New LaCaCuZnMnO6 Copper–Zinc Manganite of Lanthanum and Calcium

Thermodynamic and Electrophysical Investigation of New Nanostructured Lanthanum and Sodium Copper–Zinc Manganite LaNa2CuZnMnO6

Thermodynamic and Electrophysical Investigation of New Nanostructured Lanthanum and Sodium Copper–Zinc Manganite LaNa2CuZnMnO6

Hydrothermally synthesized cubical zinc manganite nanostructure for electrocatalytic detection of sulfadiazine.

An electrocatalyst modified electrode has been investigatedto develop the rapid detection of antibiotics. The modified electrocatalyst was intended for the determination of sulfadiazine (SFZ) in biological fluids by electrochemical methods. Nanocube of zinc manganite (ZnMn2O4-NC) is prepared by hydrothermal method and a glassy carbon electrode (GCE) has been modified withthe zinc manganite. The ZnMn2O4/GCE exhibit enhanced detection performances towards SFZ drug owing to their selective adsorption ability and the combination of electrostatic attraction of nanocube with SFZ. The modified electrocatalyst shows excellent electrocatalytic interactions with antibiotic drug. Besides, the modified sensors exhibit nanomolar detection limit (0.0021μM) in 0.05M phosphate buffer (pH = 7.0) using differential pulse voltammetric method. The working range of the modified electrode is 0.008-1264μM, and the sensitivity of the SFZ sensor is 11.44μA μM-1 cm-2. The modified sensor stability and reproducibility performances have been examined by electrochemical method. In addition, the obtained results of real sample analysis with different concentrations of SFZ in biological fluids are satisfactory with good recovery.

Construction of chemical self-charging zinc ion batteries based on defect coupled nitrogen modulation of zinc manganite vertical graphene arrays

Self-charging power systems, which can simultaneously achieve energy harvesting and storage, play a significant role in the field of energy technology.

Functional properties of quaternary metals (1 − x)ZnMn2O4/(x)MgFe2O4 as supercapacitor electrode

Solid solutions from $$(1-x){\mathrm{ZnMn}}_{2}{\mathrm{O}}_{4}/(x){\mathrm{MgFe}}_{2}{\mathrm{O}}_{4}$$ (x = 0.0, 0.1, 0.5, 0.9, 1.0) were obtained by a simple sol–gel procedure. A single-phase tetragonal spinel zinc manganite was identified by X-ray phase analysis for the samples x = 0.0 and 0.1, whereas a single-phase cubic spinel magnesium ferrite was identified for x = 0.5, 0.9, and 1.0. The formation of these phases was confirmed by the analysis of FTIR absorption spectra measured for the obtained samples. A scanning electron microscope was used to identify the different elements in the formed solid solution. Transmission electron microscope together with Rietveld profile method emphasized the nano-nature of the obtained samples. The influence of the composition parameter (x) on the optical properties of the solid solutions was explored utilizing UV–Vis diffuse reflectance spectroscopy measurements. The magnetic measurements revealed the conversion of the paramagnetic nature of ZnMn2O4 samples into ferromagnetic nature as it couples with MgFe2O4 sample in $$(1-x){\mathrm{ZnMn}}_{2}{\mathrm{O}}_{4}/(x){\mathrm{MgFe}}_{2}{\mathrm{O}}_{4}$$ solid solution. The supercapacitor performance of all samples was examined by cyclic voltammetry and galvanostatic charge–discharge studies.

Investigation on structural, optical and electrochemical behavior of NiO/ZnMn2O4 ternary nanocomposites via two-step synthesis approach for supercapacitor application

The present investigation deals with the synthesis of nickel oxide (NiO)/zinc manganite (ZnMn2O4) nanocomposites (NCs) by a two-step approach. The powder X-ray diffraction (PXRD) pattern revealed the existence of face-centered cubic (FCC) phase of NiO and tetragonal rutile phase structure of ZnMn2O4 in NiO/ZnMn2O4 NCs. The optical properties of NiO/ZnMn2O4NCs have been investigated by the UV-diffuse reflectance Spectroscopy (UV-DRS) and photoluminescence (PL) spectral analysis. The surface morphology and elemental composition of NiO/ZnMn2O4NCs was investigated by field emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectrum (EDX) analysis. The surface area and the nature of porosity of the samples were analyzed using Brunauer–Emmett–Teller (BET) method. The electrochemical properties were investigated from the cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS) measurements. In 0.5 M potassium hydroxide (KOH) electrolyte solution, NiO/ZnMn2O4NCs exhibited higher specific capacitance of 886 F/g at a current density of 1Ag−1 with high cyclic stability over 1000 charge–discharging cycles. Thus, the result demonstrates that the prepared NiO/ZnMn2O4NCs is a promising electrode material for future energy-storage devices.

Synthesis and Structural Studies of Zn0.95Cu0.05Mn2O4 Ceramics

AbstractThe fabrication of Zn0.95Cu0.05Mn2O4 ceramic material is obtained by simple chemical route (co‐precipitation method) at 600˚C. The sample is characterized by X‐ray diffraction (XRD) and scanning electron microscope (SEM). The diffraction pattern in comparison with the JCPDS card #96‐901‐2843, confirms the spinel tetragonal structure with lattice parameters a = 5.9365 Å and c = 8.6422 Å, unit cell volume of 304.573 Å3. The other possible parameters like crystallite size, X‐ray density, dislocation density, micro strain, and texture co‐efficient are reported using XRD analysis. The micro strain and crystallite size are correlated with the respective values got from Williamson–Hall and size‐strain analysis method. The SEM image showed the clouds like algae structure with grain size 3.934 µm. The effect of copper doping on structure and morphology of zinc manganite is evidenced.

Correction to: Physicochemical and Magnetic Properties of Nickel-Substituted Zinc Manganite Nanoparticles

Correction to: Physicochemical and Magnetic Properties of Nickel-Substituted Zinc Manganite Nanoparticles

Studies on electrochemical properties of SnO2/ZnMn2O4 ternary nanocomposites developed via two step approach for energy storage application

In the present work, tin oxide (SnO2)/Zinc manganite (ZnMn2O4) nanocomposites (NCs) were prepared via two step approach. The pure ZnMn2O4 NPs and SnO2/ZnMn2O4 NCs were developed from co-precipitation and hydrothermal method. The Powder x-ray Diffraction (PXRD) pattern demonstrates that the existence of spinel cubic and tetragonal rutile phase structure of ZnMn2O4 and SnO2/ZnMn2O4 NCs. The two peaks are located at 531 cm−1 and 618 cm−1 is originating from the metal oxide stretching vibration bonds of Mn–O and Sn-O. The spherical and cubic morphology was determined from the prepared ZnMn2O4 and SnO2/ZnMn2O4 NCs and elemental compositions of prepared material were identified in EDAX analysis. The electrochemical performance of the prepared material investigates by cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS) measurements. From the electrochemical study, specific capacitance behavior with high capacitance attained about 658 F g−1 in (6 M) KOH electrolyte solution at the current density 1 A g−1. These superior electrochemical features exhibit that the prepared SnO2/ZnMn2O4 NCs acts as a potential candidate for next-generation supercapacitor systems.