Manganese Oxide Nanoparticles Research Articles

Electrophoretic deposition of manganese oxide nanoparticles on aluminum substrate under different electrophoretic conditions

Electrophoretic deposition of manganese oxide nanoparticles on aluminum substrate under different electrophoretic conditions

Electrochemical sensor based on carbon nanotube decorated with manganese oxide nanoparticles for naphthalene determination.

In this work, an electrochemical sensor was developed for the determination of naphthalene (NaP) in well water samples, based on a glass carbon electrode (GCE) modified as a nanocomposite of manganese oxides (MnOx) and COOH-functionalized multi-walled carbon nanotubes (MWCNT). The synthesis of MnOx nanoparticles was performed by the sol-gel method. The nanocomposite was obtained by mixing MnOx and MWCNT with the aid of ultrasound, followed by stirring for 24h. Surface modification facilitated the electron transfer process through the MnOx/MWCNT/GCE composite, which was used as an electrochemical sensor. The sensor and its material were characterized by cyclic voltammetry (CV), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Important parameters influencing electrochemical sensor performance (pH, composite ratios) were investigated and optimized. The MnOx/MWCNT/GCE sensor showed a wide linear range of 2.0-16.0μM, a detection limit of 0.5μM and a quantification limit of 1.8μM, in addition to satisfactory repeatability (RSD of 7.8%) and stability (900s) in the determination of NaP. The determination of NaP in a sample of water from a gas station well using the proposed sensor showed results with recovery between 98.1 and 103.3%. The results obtained suggest that the MnOx/MWCNT/GCE electrode has great potential for application in the detection of NaP in well water.

High-performance asymmetric supercapacitors utilizing manganese oxide nanoparticles grafted graphitic carbon nitride nanosheets as the cathode and hypercross-linked polymer derived activated carbon as the anode

Herein, we demonstrated the inexpensive construction of a high-performance asymmetric supercapacitor (ASC) that was combined with manganese oxide nanoparticles grafted graphitic carbon nitride nanosheets (Mn3O4@GCN-NS) as the cathode and nitrogen doped hypercross-linked polymer derived activated carbon (NHCP-AC) as the anode with 6.0 M aqueous KOH electrolyte. In the beginning, Mn3O4@GCN-NS was successfully prepared via a single-step pyrolysis assisted method and the NHCP-AC was synthesized via Friedel-Crafts reaction. The as-synthesized nanocomposites exhibited higher specific capacitance of 436.2 at 0.5 A g−1 in three-electrode cell configuration. Furthermore, the ASC device was fabricated by integrating Mn3O4@GCN-NS with NHCP-AC, which demonstrated considerable energy density of 22.2 Wh/kg at 400 W/kg power density together with remarkable cyclability (93.5 % capacitive retention even after 5000 cycles of charge and discharge). The light emitting diode (5 mm dia.) was powered for about 15 min using two ASC devices coupled in series, demonstrating the effectiveness of its power source. Thus, the results demonstrated that the ASC devices have enormous potential for investigating cutting-edge applications in the field of advanced energy storage.

Study of protein encapsulated manganite nanoparticles for magnetic Hyperthermia

Used in the past as an efficient drug-delivery carrier, the natural protein Bovine Serum Albumin (BSA) has been tried in the present study to coat Lanthanum Strontium Manganese Oxide (LSMO) nanoparticles (NPs) called manganite, for magnetic Hyperthermia applications. LSMO NPs generate heat when subjected to a radiofrequency magnetic field and as a novel attempt; they were functionalized with BSA by its “denaturation” at 80°C. This was done to probe the effect of protein bonding with nanoparticles by “unfold” of its molecular structure and to enhance the biocompatibility of LSMO. Presence of BSA on NPs was assessed through electron microscopy (HRTEM), Fourier transform (IR) spectroscopy and thermogravimetric analysis (TGA); that showed successful outcomes. The magnetization was analyzed by super quantum interface device (SQUID). For Hyperthermia studies, BSA coated NPs were dispersed in phosphate buffer saline and attained an appreciable specific absorption rate of 126.9 W/g showing their potential for future applications.

Caveat Emptor: Commercialized Manganese Oxide Nanoparticles Exhibit Unintended Properties.

Nano-encapsulated manganese oxide (NEMO) particles are noteworthy contrast agents for magnetic resonance imaging (MRI) due to their bright, pH-switchable signal ("OFF" to "ON" at low pH), high metal loading, and targeting capability for increased specificity. For the first time, we performed a head-to-head comparison of NEMO particles from In-house and commercialized sources (US Nano vs Nanoshel) to assess their potential as bright T1 MRI contrast agents. Manganese oxide nanocrystals (MnO, Mn2O3, and Mn3O4) were systematically evaluated for size, chemistry, release of manganese ions, and MRI signal pre- and post-encapsulation within poly(lactic-co-glycolic acid) (PLGA). Suprisingly, a majority of the commercialized formulations were not as advertised by displaying unintended sizes, morphologies, chemistry, dissolution profiles, and/or MRI signal that precludes in vivo use. US Nano's Mn3O4 and Mn2O3 nanocrystals contained impurities that impacted Mn ion release as well as micron-sized rodlike structures. Nanoshel's MnO and Mn2O3 nanoparticles had very large hydrodynamic sizes (>600 nm). In-house MnO and Nanoshel's Mn3O4 nanoparticles demonstrated the best characteristics with brighter T1 MRI signals, small hydrodynamic sizes, and high encapsulation efficiencies. Our findings highlight that researchers must confirm the properties of purchased nanomaterials before utilizing them in desired applications, as their experimental success may be impacted.

Characterization of Mn3 O4 -MnO2 nanocomposites biosynthesized by cell lysate of Haloferax alexandrinus GUSF-1.

Manganese oxide nanocomposites attract huge attention in various biotechnological fields due to their extensive catalytic properties. This study reports an easy, rapid, and cost-effective method of using the cell lysate of haloarchaeon, Haloferax alexandrinus GUSF-1 for the synthesis of manganese oxide nanoparticles. The reaction between the cell lysate and manganese sulfate resulted in the formation of a dark brown precipitate within 48 h at room temperature. The X-ray diffraction pattern showed the existence of Mn3 O4 and MnO2 phases consistent with the JCPDS card no. (01-075-1560 and 00-050-0866). The dark brown colloidal suspension of MnO3 -MnO2 in methanol showed maximum absorption between 220 and 260 nm. The EDX spectrum confirmed the presence of manganese and oxygen. The Transmission electron microscopy revealed the spherical morphology with an average particle size between 30 and 60 nm. The magnetic moment versus magnetic field (MH) curve, at room temperature (300 K) did not saturate even at a high magnetic field (±3T) indicating the paramagnetic nature of the prepared nanocomposite. The Atomic Emission Spectroscopic analysis showed a negligible amount of soluble manganese (0.03 ppm in 50 ppm) in the Mn3 O4 -MnO2 suspension suggesting the maximum stability of the material in the solvent over time. Interstingly, Mn3 O4 -MnO2 nanocomposites evidenced antimicrobial activity in the order of Pseudomonas aeruginosa > Salmonella typhi > Escherichia coli > Proteus vulgaris > Candida albicans > Staphylococcus aureus. Conclusively, this is the first report on the formation of Mn3 O4 -MnO2 nanocomposites using cell lysate of salt pan haloarcheon Haloferax alexandrinus GUSF-1 with antimicrobial potential.

Sonochemical Synthesized Manganese Oxide Nanoparticles as Fluorescent Sensor for Selenium (IV) Quantification. Application to Food and Drink Samples.

Manganese oxide nanoparticles (MnO Nps), sonochemical synthesized and characterized in our laboratory, are proposed as fluorescent sensor for selenium (Se) determination. The new methodology has been developed based on the enhancing effect of the Se(IV) on fluorescent emission of MnO Nps. Experimental variables that influence on fluorimetric sensitivity were optimized. The calibration graph using zeroth order regression was linear from 0.189ng L-1 to 8.00 × 103µg L-1, with correlation coefficient better than 0.99. Under the optimal conditions, the limits of detection and quantification were of 0.062ng L-1 and 0.189ng L-1, respectively. The trueness of the methodology was assessed through standard addition method obtaining recovery near to 100%. This method showed good tolerance to foreign ions, particularly to Se(VI), and was applied to determination of Se(IV) trace in food and drink samples with satisfactory results. With the intention of preserving the environment from harmful effects, a degradation study of the used nanomaterials has been included for their subsequent disposal.

Manganese Oxide Nanoparticles: An Insight into Structure, Synthesis and Applications

AbstractManganese oxide nanoparticles with different crystal phases, morphologies, and structural diversity along with their exceptional properties like high specific surface area, a high fraction of surface atoms, non‐toxic nature, and excellent redox properties are drawing attention for various applications in storage science, especially in the batteries, super‐capacitors, energy conversion, and the environmental catalysis field. Precise control of particle size, morphology, surface area, Mnx+ oxidation state, etc. is the utmost important aspect to explore their application to the full potential. Here, the emphasis is on the recent trends in manganese oxide research – structure, synthesis, and applications. The structure of numerous crystalline phases of manganese oxide nanoparticles are summerized and several facile chemical synthesis processes to achieve the desired crystalline/amorphous structure are discoursed. Temperature and different synthesis conditions dependent phase transformations of β‐MnO2, α‐Mn2O3, and Mn3O4 from α‐MnO2 are discussed as well. The pragmatic approach directs that the application field is mostly controlled by the morphologies.

One-Step Plasma-Assisted Electrochemical Synthesis of Nanocomposites of Few-Layer Graphene Structures with Manganese Oxides as Electrocatalysts for Oxygen Reduction Reaction

Using the method of plasma-assisted electrochemical exfoliation of graphite, a nanocomposite, which consists of few-layer graphene structures with surface decorated with manganese oxides nanoparticles, is synthesized in one-step process. It is found that this material exhibits a high electrocatalytic activity towards the oxygen reduction reaction due to the presence of manganese in the +2 and +3 oxidation states, and also carbonyl (quinone) functional groups on the surface of graphene structures.

Influence of bio fabricated manganese oxide nanoparticles for effective callogenesis of Moringa oleifera Lam

The use of nanoscale fertilizers to boost crop output has increased in recent years. Nanoparticles (NPs) can stimulate the biosynthesis of bioactive compounds in plants. It is the first report on biosynthesized manganese oxide nanoparticles (MnO-NPs) that mediate in-vitro callus induction of Moringa oleifera. To achieve better biocompatibility the leaf extract of Syzygium cumini was used to synthesize MnO-NPs. Scanning electron microscope SEM revealed spherical shaped morphology of MnO-NPs with an average diameter of 36 ± 0.3 nm. Energy-dispersive X-ray spectroscopy (EDX) depicted the formation of pure MnO-NPs. X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) authenticate the crystalline structure. UV–visible absorption spectroscopy depicted the activity of MnO-NPs under visible light. The biosynthesized MnO-NPs were concentration-dependent and revealed promising results in callus induction of Moringa oleifera. It was found that MnO-NPs enhance callus production of Moringa oleifera and keep the callus infection free by providing an optimum environment for rapid growth and development. Therefore MnO-NPs synthesized through the green process can be utilized in tissue culture studies. This study concludes that MnO is one of the essential plant nutrients that have tailored nutritive properties at a nano scale.

Rough Nanovaccines Boost Antitumor Immunity Through the Enhancement of Vaccination Cascade and Immunogenic Cell Death Induction.

Nanovaccines have attracted intense interests for efficient antigen delivery and tumor-specific immunity. It is challenging to develop a more efficient and personalized nanovaccine to maximize all steps of the vaccination cascade by exploiting the intrinsic properties of nanoparticles. Here, biodegradable nanohybrids (MP) composed of manganese oxide nanoparticles and cationic polymers are synthesized to load a model antigen ovalbumin to form MPO nanovaccines. More interestingly, MPO could serve as autologous nanovaccines for personalized tumor treatment taking advantage of in situ released tumor-associated antigens induced by immunogenic cell death (ICD). The intrinsic properties of MP nanohybrids including morphology, size, surface charge, chemical, and immunoregulatory functions are fully exploited to enhance of all steps of the cascade and induce ICD. MP nanohybrids are designed to efficiently encapsulate antigens by cationic polymers, drain to lymph nodes by appropriate size, be internalized by dendritic cells (DCs) by rough morphology, induce DCmaturation through cGAS-STING pathway, and enhance lysosomal escape and antigen cross-presentation through the "proton sponge effect". The MPO nanovaccines are found to efficiently accumulate in lymph nodes and elicit robust specific T-cell immune responses to inhibit the occurrence of ovalbumin-expressing B16-OVA melanoma. Furthermore, MPO demonstrate great potential to serve as personalized cancer vaccines through the generation of autologous antigen depot through ICD induction, activation of potent antitumor immunity, and reversal of immunosuppression. This work provides a facile strategy for the construction of personalized nanovaccines by exploiting the intrinsic properties of nanohybrids.

Multiphase manganese oxide nanoparticles suitable for optical and catalytic applications

In the current research work, we have synthesized and characterized the manganese oxide nanoparticles dispersed in silica via the sol–gel method. The outcomes and phenomenon associated with structural morphology are put forward for different applications. Nanocrystalline manganese oxide was annealed at various temperatures as 300℃, 600℃, and 900 °C. The Structural properties of the prepared powder were determined by using X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) spectra. Whereas surface morphology was explored through Scanning Electron Microscope (SEM), EDX, etc. The average crystalline size of ∼ 16.5 nm has been obtained using well known Debye-Scherer's formula. After a study of multiphase manganese oxide nanoparticles, the results of optical and catalytic behavior were obtained which give rise to many applications in the optoelectronic industry as well as in the catalytic industry. In the nanometer-size of the prepared powders, the maximum of the active sites lies at the exterior, therefore such materials could be extra efficient catalysts than their micrometer/bulk counterparts. In the present study, the role of crystallite size and surface area is elaborated to explore the industrial-scale application of the prepared multiphase manganese oxide nanoparticles.

Optimizing In Situ Combustion with Manganese (II) Oxide Nanoparticle-Catalyzed Heavy Oil Oxidation

The combustion front is a crucial parameter in determining the efficiency of in situ combustion techniques during enhanced oil recovery. Nowadays, catalytic systems are widely believed to be an efficient tool to stabilize the combustion front. This study aimed to investigate the synthesis and catalytic activity of manganese (II) oxide nanoparticles in the high-temperature oxidation of heavy oils. The synthesis and catalytic activity of manganese (II) oxide nanoparticles in the high and low-temperature oxidation regions of heavy oil were investigated in this study. The obtained nanoparticles were characterized and studied by using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), thermogravimetric analysis (TG), nitrogen adsorption and desorption measurements, and differential scanning calorimetry (DSC) thermal analysis combined with the Kissinger isoconversional method. The obtained results showed that the synthesized nanoparticles had an average size of 17 ± 4 nm and a specific surface area of 38.2 ± 0.1 m2 g−1, with a pore size distribution of ~8 nm. The low and high-temperature oxidation processes’ activation energies were found to be 98.9 ± 0.7 kJ/mol and 151.9 ± 0.6 kJ/mol, respectively, in the presence of nanoparticles. However, these parameters were found to be equal to 110.1 ± 1.8 kJ/mol and 142.8 ± 8.3 kJ/mol, respectively, in the absence of nanoparticles. These data were processed further by calculating the corresponding reaction rates. The obtained results indicated that the rate of heavy oil oxidation was higher in the presence of the synthesized nanoparticles, which could play a critical role in stabilizing the combustion front in the in situ combustion process.

Synthesis and Characterization of Zinc, Iron, Copper, and Manganese Oxides Nanoparticles for Possible Application as Plant Fertilizers

This research evaluates the synthesis and characterization of nanometric-sized metallic particles with potential application as support materials for supplying nutrients to plants. Nanoscale Zn, Mn, Fe, and Cu oxides particles were synthesized using microwave-assisted synthesis. Nanoparticles (NPs) were characterized with Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), specific surface area (SSA), and total chemical analysis. Synthesized NPs were all in oxide forms and characterized for confirmation of size, shape, surface structure, crystalline nature, and study of elemental proportion. The results indicate that synthesized NPs size was ranged between 20 and 50 nm and was all in their respective oxide forms as ZnO, Mn3O4, Fe3O4, and CuO.

Chemically synthesized manganese oxide nanorods for effectual organic dye removal and energy storage application

Manganese oxide nanoparticles (MnO2) are successfully synthesized by using a facile chemical co-precipitation and reflux-assisted co-precipitation method with varying annealing temperatures and reflux time respectively. The synthesized samples' structural, optical and thermal properties are investigated by XRD, FTIR spectra, Ultraviolet–Visible spectroscopy, Thermogravimetric Analysis and BET surface area analyzer. The average crystallite sizes assessed by Scherrer's equation (Williamson- Hall plot) of prepared samples are in the range of 6–8 nm (6–7 nm) for the reflux-assisted method and 15–30 nm (20–46 nm) for the co-precipitation method respectively. The presence of peaks associated with Mn-O bonds in FTIR spectra confirmed the formation of MnO2 nanoparticles. FESEM studies revealed the nanorod-type morphologies of samples. The prepared samples showed pseudocapacitive behaviour and significant photocatalytic degradation of brilliant green dye.

Single-step synthesis of Mn3N2, MnxON and Mn3O4 nanoparticles by thermal plasma arc discharge technique and their comparative study as electrode material for supercapacitor application

In the present study, single-step synthesis of single-phase manganese nitride (Mn3N2), mixed phase manganese oxynitride (MnxON) and manganese oxide (Mn3O4) nanoparticles (NPs) was carried out using the thermal plasma arc discharge (TPAD) method. The experiments were carried out using nitrogen (N2), ammonia (NH3) and oxygen (O2) gas atmospheres at different plasma powers 2, 4 and 6 kW. The phase and elemental compositions of the prepared nanoparticles were examined using X-Ray Diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDX) analysis. All the synthesized powder samples have nearly spherical morphology, which are determined by using Field Emission Scanning Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM) analysis. The surface area of the prepared NPs was investigated using Brunauer-Emmett-Teller (BET) analysis, and the obtained results are 40.1, 19.4 and 11.8 m2g−1 for Mn3N2, MnxON and Mn3O4 NPs respectively. The Mn3N2 NPs showed superior storage performance with an outstanding specific capacitance of 508.4 F/g at 1 A/g with pseudocapacitive behavior compared to the mixed and oxide NPs 335.1 and 150 F/g respectively. The Mn3N2 electrode exhibited higher cycling stability with 84.2% capacitance retention after 5000 cycles at a current density of 5 A/g. These results demonstrated that the plasma-prepared single-phase Mn3N2, which is used as a potential electrode material for supercapacitors applications.

Exploring the optical properties of MnO2 nanoparticles doped PVP for optoelectronics devices

Numerous applications for optical technologies used the nanocomposites. The purpose of this work is to create novel kinds of polymer nanocomposites and analyze their optical characteristics. The polyvinyl pyrrolidone (PVP)/ manganese oxide nanoparticle (MnO2NPs) nanocomposites were created. Various content of PVA and MnO2 NPs were fabricated. The optical characteristics of these nanocomposites were examined. The results demonstrate that the absorbance, coefficient of absorption, index of refractive, coefficient of extinction, dielectric constant and conductivity of PVP are raise with arise of the MnO2NPs content. The transmittance and gap of energy are reduced with a rise of the MnO2NPs content. The results illustrated the PVP/MnO2nanostructures may be utilized in different photonics and optics fields.

Treatment of produced water using Mn oxide nanoparticales loaded on walnut shells

Sorption of 226Ra from produced water with oil production on manganese oxide nanoparticles loaded on walnut shell media was investigated using batch-type technique. The results showed that 226Ra is effectively adsorbed onto the adsorbent with equilibrium time of approximately 30 min. Removal efficiency of 226Ra from produced water depends mainly on the adsorbent dose and concentration of associated ions; removal efficiency decreased when their concentrations increase. The maximum adsorption capacity is reached 58 Bq g−1. The adsorbent is effective and suitable for removing 226Ra ions from the produced water under the studied conditions in this work.

Nanoscale chemical and structural investigation of solid solution polyelemental transition metal oxide nanoparticles

Although it has been shown that configurational entropy can improve the structural stability in transition metal oxides (TMOs), little is known about the oxidation state of transition metals under random mixing of alloys. Such information is essential in understanding the chemical reactivity and properties of TMOs stabilized by configurational entropy. Herein, utilizing electron energy loss spectroscopy (EELS) technique in an aberration-corrected scanning transmission electron microscope (STEM), we systematically studied the oxidation state of binary (Mn,Fe)3O4, ternary (Mn, Fe, Ni)3O4, and quinary (Mn, Fe, Ni, Cu, Zn)3O4 solid solution polyelemental transition metal oxides (SSP-TMOs) nanoparticles. Our findings show that the random mixing of multiple elements in the form of solid solution phase not only promotes the entropy stabilization but also results in stable oxidation state in transition metals spanning from binary to quinary transition metal oxide nanoparticles.

Innentitelbild: Altering Oxygen Binding by Redox‐Inactive Metal Substitution to Control Catalytic Activity: Oxygen Reduction on Manganese Oxide Nanoparticles as a Model System (Angew. Chem. 8/2023)

Redox-inactive substituents steer the activity of manganese oxide nanoparticles, Mn3O4:M, in the oxygen reduction reaction (ORR). In their Research Article (e202217186), Denis Kuznetsov, Christoph Müller, and co-workers describe how the ORR activity of Mn3O4:M correlates with the enthalpy of formation of the binary MO oxide and the Lewis acidity of the M site. The work generalizes the role of redox-inactive elements in influencing the kinetics of electrocatalytic reactions and provides a perspective on the design of new catalyst compositions.