Mn Doped SnO2 Nanoparticles Research Articles

Phyto-synthesis of Pure and Mn Doped SnO2 Nanoparticles: Evaluation of Antimicrobial, Antioxidant and Photocatalytic Activities

Phyto-synthesis of Pure and Mn Doped SnO2 Nanoparticles: Evaluation of Antimicrobial, Antioxidant and Photocatalytic Activities

A simple fabrication of Mn doped SnO2 nano particles towards improved congored degradation photocatalytic activity

A simple fabrication of Mn doped SnO2 nano particles towards improved congored degradation photocatalytic activity

Effect of dopant concentration Mn in SnO2 nanoparticles on photocatalytic, magnetic and optical properties

Mn doped SnO2 nanoparticles were synthesized in a sol-gel technique at various concentrations. A wide range of properties are analyzed by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with energy dispersive spectroscopy (SEM with EDAX), Transmission Electron Microscopy (TEM), UV-Visible spectroscopy, photoluminescence spectroscopy (PL), Vibrating Sample Magnetometer (VSM), and photocatalytic studies. Results from EDAX confirmed the presence of Sn and Mn ions in SnO2 nanoparticles doped with Mn. As a result of analyzing the luminescence of all synthesized samples, blue emission characteristic of lighting applications was observed. Furthermore, 0.2M Mn doped SnO2 sample shows the enhanced ferromagnetism at room temperature with elevated saturation magnetization value. The 0.2M Mn doped SnO2 nanoparticles show the significant increase in photocatalytic efficiency of SnO2 among the other doped samples. Thus, all experiment results demonstrated that the concentration of dopant influences the structure, optical properties, photocatalytic properties, and magnetic properties of SnO2.

Optical and electrical properties of pure and doped tin oxide nanoparticles

Optical and electrical properties of pure, Co- and Mn-doped tin oxide (SnO2) nanoparticles (NPs) were studied and reported. The materials were successfully prepared by simple co-precipitation method. The developed SnO2 NPs exhibit tetragonal structure with space group P42/mnm. Addition of dopants reduces the particle size from 23 nm (pure SnO2 NPs) to 18 and 16 nm (Mn- and Co-doped SnO2 NPs). The estimated band gap energy of pure, Co-, and Mn-doped SnO2 NPs were found to be 3.43, 2.70 and 2.84 eV, respectively. FTIR and EDX analyses also confirmed the incorporation of Mn and Co into the pure SnO2 NPs. Scanning electron micrograph revealed that the synthesized NPs were formed as large spherical shape by the aggregation of small individual nanoparticle. Photoluminescence spectrum of synthesized NPs shows the emission peaks in the visible region. Electrical properties of the proposed materials were studied from current (I) and voltage (V) characteristics. The results confirm the semiconducting behavior of the material and the I–V curves of all the samples reveal the nonlinear behavior of the synthesized materials.

Transition metal doped Sb@SnO2 nanoparticles for photochemical and electrochemical oxidation of cysteine

Transition metal-doped SnO2 nanoparticles (TM-SnO2) were synthesized by applying a thermos-synthesis method, which first involved doping SnO2 with Sb and then with transition metals (TM = Cr, Mn, Fe, or Co) of various concentrations to enhance a catalytic effect of SnO2. The doped particles were then analyzed by using various surface analysis techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning transmission X-ray microscopy (STXM), and high-resolution photoemission spectroscopy (HRPES). We evaluated the catalytic effects of these doped particles on the oxidation of L-cysteine (Cys) in aqueous solution by taking electrochemical measurements and on the photocatalytic oxidation of Cys by using HRPES under UV illumination. Through the spectral analysis, we found that the Cr- and Mn-doped SnO2 nanoparticles exhibit enhanced catalytic activities, which according to the various surface analyses were due to the effects of the sizes of the particles and electronegativity differences between the dopant metal and SnO2.

Effect of Mn doping on the structural, morphological and optical properties of SnO2 nanoparticles prepared by Sol-gel method

(0wt%, 3wt% and 4wt%) Mn doped SnO2 nanoparticles were synthesized via sol-gel method. The as-prepared nanoparticles were characterized by Scanning Electron Microscopy (SEM), Transition Electron Microscopy (TEM), X-ray diffraction (XRD) and UV-Visible spectroscopy. Moreover, the effects of manganese doping on structural, morphological and optical properties were investigated. The results show that the small difference in Mn ratio for doped samples leaves a significant effect in the band gap. The crystallite size and the optical band gap of SnO2 nanoparticles varied with Mn concentration. The optical band gap of (0wt%, 3wt% and 4wt%) Mn doped SnO2 nanoparticles were found to be 3.59eV, 3eV, and 2.63eV, respectively.

Room temperature variation in dielectric and electrical properties of Mn doped SnO2 nanoparticles

Pure and Mn doped SnO2 nanoparticles of the composition MnxSn(1-x)O2 where (x = 0.0, 0.03, 0.05, 0.07) were synthesized by sol gel auto combustion method. Structural studies performed by XRD and EDS suggest that the crystal system remains pure rutile with a tetragonal structure even after the doping of Mn. The EDS analysis reveals that both Sn and Mn elements are present in the sample which confirmed the successful doping of Mn in the SnO2 host structure. The identification of the various chemical bonds present in the pure and Mn doped samples has been carried out through Fourier Transform Infrared spectroscopy. FTIR spectrum has been recorded in solid phase using KBr pellets technique in the regions of 4000–400 cm-1. The complex dielectric constant, complex impedance, and a.c. conductivity have been studied as function of frequency and composition using LCR meter. Dielectric constant and loss was found to decrease with the increase in frequency and the obtained results have been explained on the basis of Maxwell-Wagner model. A.C. conductivity was found to increase with the increase in frequency due to hopping between charge carriers. It increases with the increase in dopant level which may be due to the free electron density and crystalline size.

Magnetic properties of microwave-synthesized Mn-doped SnO2 nanoparticles

Semiconductor nanostructures with dilute magnetic property are of great importance for different applications. However, this property depends on several factors including the synthesis route. In this work, manganese (Mn)-doped tin dioxide (SnO2) nanoparticles (NPs) at different concentrations were synthesized by the microwave-assisted synthesis method and evaluated for their magnetic properties. The X-ray diffraction analyses revealed a single-phase rutile-type tetragonal structure, while SEM and TEM images showed fine NPs with average sizes around 10 nm. A considerable increase in value of the energy band gap by around 0.18 eV as a result of Mn doping was observed. This dopant has also increased the lattice d-spacing value, but slightly decreased the lattice constant c. The magnetic measurement result showed that all the microwave-synthesized Mn-doped SnO2 NPs including the pure one have distinctly wide hysteresis loops, indicating that samples have room temperature ferromagnetism (RTFM). RTFM was further enhanced by Mn doping reaching maximum at a concentration of 0.3 mol%. This magnetism could be attributed to the presence of defects at the grain boundaries within the NPs, interfacing sites between the NPs, oxygen or tin vacancies and an optimum level of Mn dopant. The observed wide hysteresis loops in these samples might be due to the use of a surfactant at high concentration that could provide highly compact/tight NPs. These results might be useful for producing nanoscale magnets and magnetic memory devices.

Structural, Optical and Magnetic Investigation of Ni, Co and Mn doped SnO2 Nano particles Synthesized by Chemical Co-precipitation.

Pure and transition metal dopednano-crystalline Sn1-xTMxO2 (x = 0.0, 0.05, TM = Ni, Co and Mn)were synthesized in aqueous solution by chemical Co-precipitation technique. X- ray diffraction (XRD), high resolution transmission electron microscope (HR-TEM), electron diffraction,UV – visible absorption spectroscopy and room temperature magnetization measurements were performed to investigate the structural and microstructural, morphology, optical and magnetic properties of pure and doped samples. The structure calculations revealed that Co and Ni atoms have been incorporatedin the SnO2hostlattice.For Mn, the XRD analysis detected that SnO phase was formed instead during the synthesis process.HRTEM and XRD studies indicated that the particle size is in the range of quantum dot size except for Mn. For optical measurement, the quantum confinement effect was suggested to be the dominant reason for the great increase of the optical bandgap with respect to the bulk material. Magnetization measurements revealed that all doped samples were ferromagnetic in nature. Well defined strong hysteresis loop was detected for Co doped SnO2 nanoparticles. It was suggested that the ferromagnetism is intrinsic in origin.It is not due to ferromagnetic metal clusters nor due to the presence of additional ferromagnetic phases. The strong ferromagnetic signal especially for Co doped SnO2makes it a candidate for spintronic applications.

Electrochemical sensor for simultaneous determination of ascorbic acid, uric acid and folic acid based on Mn-SnO2 nanoparticles modified glassy carbon electrode

A highly sensitive and selective electrochemical sensor was fabricated based on Mn doped SnO2 nanoparticles (NPs) modified glassy carbon electrode (Mn-SnO2/GCE) for simultaneous determination of ascorbic acid (AA), uric acid (UA) and folic acid (FA) for the first time. The Mn-SnO2 NPs synthesized by microwave irradiation method were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and square wave voltammetry (SWV) techniques. The Mn-SnO2/GCE exhibited excellent electrocatalytic activity towards the oxidations of AA, UA and FA in phosphate buffer solution (pH6.0) and the corresponding electrochemical signals have appeared as three well resolved oxidation peaks with significant peak potential differences of 0.141V (AA–UA), 0.345V (UA–FA) and 0.486V (AA–FA). For selective determination, the linear responses of AA, UA and FA were in the concentration ranges of 1 to 900, 1 to 860 and 0.5 to 900μM for AA, UA and FA with detection limits of 56, 36 and 79nM respectively. For simultaneous determination by synchronous change of the analyte concentrations, the linear response ranges were between 5 and 500μM for UA and 1–500μM for FA with the lowest detection limits of 25 and 38nM respectively in the presence of AA. The proposed sensor was proved to be applicable for the determination of the target analytes in pharmaceuticals and urine samples.

Formation of Mn-Doped SnO2 Nanoparticles Via the Microwave Technique: Structural, Optical and Electrical Properties

Ultrafine pure and Mn-doped SnO2 nanoparticles (NPs) were synthesized via the microwave technique. They were produced using tin chloride and hexamethylenetetramine at the molar ratio of 1:20. The c...

Effect of Mn doping on structural, optical and magnetic properties of SnO2 nanoparticles

The Mn doped SnO2 nanoparticles synthesized by cost effective chemical co-precipitation method has been investigated in the present work. The main focus of the work is to explore the structural, optical and magnetic properties of the SnO2 nanostructures. The crystallite size decreases with increase in Mn doping to SnO2 matrix. The optical band gap of doped SnO2 nanoparticles continuously decreases with increasing Mn ion doping concentration. All the doped SnO2 nanoparticles show paramagnetic behavior at room temperature. SnO2 exhibits ferromagnetic behavior in the range of low external applied magnetic field due to the presence of oxygen vacancies (V o + ) and defects. The undoped SnO2 nanoparticles are spherical in shape while Mn doped SnO2 nanoparticles show the segregation of the spherically shaped nanoparticles. Mn ions only enhance the paramagnetic ordering and degrade the ferromagnetism already present in the SnO2 nanoparticle.

Influence of Mn doping on structural, optical and acetone gas sensing properties of SnO2 nanoparticles by a novel microwave technique

In the present work we have successfully synthesized pristine and manganese (Mn) doped SnO2 nanoparticles by using simple microwave irradiation technique for the first time. Powder X-ray diffraction results confirms that both the pure and doped SnO2 in tetragonal rutile type structure. Transmission electron microscopy studies illustrate that both the undoped and Mn doped SnO2 crystallites form in spherical shapes with an average diameter of 35–19 nm, which is in good agreement with the average crystallite sizes calculated by Scherrer’s formula. A considerable red shift in the absorbing band edge was observed with increasing of Mn content (0–10 wt%) by using UV–Vis diffuse reflectance spectroscopy . Oxygen-vacancies, tin interstitial and structural defects were analyzed using photoluminescence spectroscopy. The functional groups were analyzed by using Fourier transform infrared spectra. Acetone gas sensing measurement of pure and Mn-doped (10 wt%) SnO2 nanoparticles were experimented at ambient temperature using optical fiber based on clad modified method. By modifying the clad exposure to acetone vapor, the sensitivities were estimated to be 53 and 78 counts/100 ppm for undoped and Mn-doped SnO2 nanoparticles, respectively. These results show that the Mn doping into SnO2 enhances acetone gas sensing properties.

Effect of Mn doping on the structural and optical properties of SnO2 nanoparticles

Mn doped SnO2 nanoparticles were synthesized by sol–gel method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDAX), UV-Visible absorption spectroscopy, photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy measurements. XRD analysis revealed the formation of single phase rutile type tetragonal structure of all samples which was further supported by Raman studies and FTIR measurements. Crystallite size was observed to vary from 16.2nm to 7.1nm as the Mn content increased from 0% to 15%, suggesting the prevention of crystal growth with Mn doping. It was evident from the absorption spectra that the absorbance tends to increase with the increase in dopant concentration. Optical band gap was calculated using Tauc relation and found to increase with the increase in Mn content confirming the size reduction as a result of Mn doping. Raman spectroscopy measurement depicted the broadening of most intense Raman peak observed at 630cm−1 with Mn doping, indicating that the Mn ions are substituted at the Sn sites in SnO2 matrix. Room temperature PL spectra revealed that the intensity of luminescent emission tends to increase with the increase in Mn concentration.

Effect of Mn-Doping on Structural, Optical, and Dielectric Properties of SnO2 Nanoparticles by Coprecipitation Method

Pure and Mn-doped SnO2 nanoparticles are prepared by co-precipitation method. The structural analysis reveals the presence of tetragonal system of SnO2. Fourier transform infrared spectroscopy (FTIR) spectra of pure SnO2 show the occurrence of O-Sn-O vibrational mode at around 671 cm−1. It is observed that the wavenumber is shifted to lower region with the increase in Mn dopant concentration. As the Mn content is increased, a clear indication of red shift is observed in the UV-vis absorption spectra. From the scanning electron microscope (SEM) image, the surface morphology of the sample shows uniformly dispersed particles, which are spherical in shape. From dielectric studies, the dielectric constant suddenly drops to 0.5 × 106 Hz, and thereafter, it shows a constant behavior. Dielectric loss plot of the prepared samples exhibits a linear behavior at higher frequency region, which suggests the samples possess a lossless nature. The ac conductivity value drops linearly with the increase in dopant level. This is due to the particle size effect and screening effect caused by the impurities.

Structure and magnetic properties in Mn doped SnO2 nanoparticles synthesized by chemical co-precipitation method

Abstract The microstructure and magnetic properties have been investigated systematically for Sn1−xMnxO2 (0 ≤ x ≤ 7%) nanoparticles synthesized by chemical co-precipitation method. The X-ray diffraction reveals that all samples are pure rutile-type tetragonal phase and the cell parameters a and c decrease monotonously with the increase of Mn content, indicated that Mn ions substitute into the lattice of SnO2. X-ray photoelectron suggests that Mn ions behave as the mixture state of Mn3+ and Mn4+ in samples. Magnetic investigations demonstrate that magnetic properties strongly depend on both the sintering temperature and doping content. No ferromagnetism is observed for samples sintered at high temperature (TS = 800 °C), irrespective of the doping content. In contrast, the samples sintered at low temperature (TS = 450 °C) possess room temperature ferromagnetism when the doping content is below 5%. A plausible explanation of the magnetic properties is presented in terms of bound magnetic polaron model.