scholarly journals Investigation of the effect of annealing temperature on photophysical properties of manganese dioxide nanostructure prepared via co-precipitation route

2020 ◽  
Vol 863 ◽  
pp. 012033
Author(s):  
M S Iqbal ◽  
M Iqbal ◽  
M Haseeb ◽  
M Aftab ◽  
A Amin ◽  
...  
Keyword(s):  
Manganese Dioxide ◽  
Annealing Temperature ◽  
Photophysical Properties ◽  
Co Precipitation

Gas Sensing Performances of Sb-Doped SnO2 Nanograins Fabricated by Co-Precipitation in Alcoholic or Aqueous Solvent

2014 ◽  
Vol 692 ◽  
pp. 460-464
Author(s):  
Lian Feng Zhu ◽  
Jue Huang ◽  
Chang Yue Zhang ◽  
Guo Sheng Gai ◽  
You Wei Yao
Keyword(s):  
Annealing Temperature ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Working Temperature ◽  
Aqueous Solvent ◽  
Air Resistance ◽  
Co Precipitation

Gas sensitivity of Sb-doped SnO2 nanograins co-precipitated respectively from ethanol and de-ionized water has been compared. Gas sensing stability of the Sb-SnO2 from ethanol (SnO2-E) was significantly superior to that of Sb-SnO2 from de-ionized water (SnO2-W): working temperature of sensor using SnO2-E was as high as 400 °C, whereas, 250 °C, for sensor using SnO2-W. Furthermore, resistance (R) of SnO2-E was less affected by annealing temperature: the ratio of air resistance annealed at 800 °C (R800) to 400 °C (R400) for SnO2-E and SnO2-W was 8 (4 kΩ/0.5 kΩ) and 1.4×105, 100 MΩ/0.7 kΩ) respectively.

Structural, Thermal and Magnetic Analysis of Co2FeO4 Spinel Oxide Synthesized by Co-Precipitation Process

2014 ◽  
Vol 895 ◽  
pp. 287-290 ◽  
Author(s):  
Pradeep Reddy ◽  
Yesu Raja ◽  
M. Ashok
Keyword(s):  
Crystallite Size ◽  
Single Phase ◽  
Annealing Temperature ◽  
Precipitation Process ◽  
Spinel Oxide ◽  
Nano Powder ◽  
Magnetic Analysis ◽  
Phase Compound ◽  
Different Temperatures ◽  
Co Precipitation

Co2FeO4spinel oxide nano powder was synthesized by co-precipitation process. Samples were annealed at different temperatures of 500, 800 and 900oC and the phase purity were also analyzed. As-prepared sample has two spinel phases and on annealing at 900οC single phase compound formed. The crystallite size of as-prepared is found to be 11.9 nm. The crystallite size increased with increase in annealing temperature to a maximum of 17.4 nm for 900 °C. Samples were subjected to necessary characterization for finding thermal, magnetic and optical band gap.

Synthesis of α-Fe2O3 nanoparticles and analyzing the effect of annealing temperature on its properties

2020 ◽  
Vol 38 (1) ◽  
pp. 116-121
Author(s):  
Bhargavi Ram Thimmiah ◽  
Gobi Nallathambi
Keyword(s):  
Size Distribution ◽  
Potassium Hydroxide ◽  
Annealing Temperature ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
The Mean ◽  
Co Precipitation ◽  
Tga Analysis ◽  
Uniform Size Distribution

Abstractα-Fe2O3 nanoparticles were synthesized via co-precipitation technique using ferric and ferrous salts and potassium hydroxide as precipitation agents. The samples were calcined at 350 °C, 550 °C and 750 °C for 3 hours. The obtained iron oxide was characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and dynamic light scattering (DLS). Crystallinity of the sample was studied by X-ray diffraction. SEM micrographs showed nonuniform size distribution of the particles forming agglomerates. TGA analysis revealed trace amount of weight loss and material stability for the samples calcined at temperatures above 500 °C. DLS results indicated that increasing of annealing temperature resulted in reduction of the particle size and more uniform size distribution. At the maximum annealing temperature of 750 °C, the mean diameter of the particles of 100 nm was observed.

scholarly journals Degradation of rhodamine B with manganese dioxide nanorods

2018 ◽  
Vol 16 (5) ◽  
pp. 846-856 ◽  
Author(s):  
V. Sabna ◽  
Santosh G. Thampi ◽  
S. Chandrakaran
Keyword(s):  
Manganese Dioxide ◽  
Rhodamine B ◽  
Initial Period ◽  
Oxidative Degradation ◽  
Cost Effective ◽  
Precipitation Method ◽  
Order Kinetic ◽  
Initial Concentration ◽  
Order Kinetic Model ◽  
Co Precipitation

Abstract This is an investigation on oxidative degradation of rhodamine B (RhB) by manganese dioxide (MnO2) nanorods synthesized by redox co-precipitation method. Field emission scanning electron microscopy of MnO2 nanorods at an electron voltage of 10 kV revealed a rod-like morphology for the synthesized nanoparticles. Fourier transform infrared spectra exhibited characteristic peaks of MnO2. Surface area of MnO2 nanorods was 277 m2/g. Effect of various parameters like initial concentration and pH of RhB solution, time of contact between MnO2 nanorods and RhB, dosage of MnO2, and stirring speed on decolouration of RhB was evaluated in batch experiments. Rapid decolouration in the initial period of the reaction was observed due to the adsorption of RhB molecules onto the surface of MnO2 nanorods followed by oxidative degradation. Percentage decolouration decreased with increase in initial concentration and increased with increase in dosage, speed of stirring the mixture and with increase in pH up to pH 7. Near complete decolouration was achieved at a dose of 0.5 g/L of MnO2 nanorods from 20 mg/L RhB solution within 3 min. Observations fitted best to the pseudo second order kinetic model. This study could pave the way for development of cost-effective, nontoxic nanostructures for treatment of wastewaters containing RhB.

Magnetic and thermodynamic properties of α, β, γ and δ-MnO2

2018 ◽  
Vol 42 (11) ◽  
pp. 8400-8407 ◽  
Author(s):  
Chunsheng Zhou ◽  
Jianfang Wang ◽  
Xin Liu ◽  
Fengying Chen ◽  
Youying Di ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Manganese Dioxide ◽  
Co Precipitation

Four different structures of manganese dioxide particles with good dispersity were obtained by hydrothermal and co-precipitation methods, and their magnetic and thermodynamic properties were studied in the temperature from (1.9 to 300) K.

scholarly journals Investigation of Magnetic and Optical Properties of Mn-Doped SnO2 at Different Annealing Temperatures

2020 ◽  
Vol 12 (4) ◽  
pp. 555-567
Author(s):  
S. Negi ◽  
A. Sharma ◽  
P. Sharma
Keyword(s):  
Optical Properties ◽  
Annealing Temperature ◽  
Systematic Investigation ◽  
Xrd Pattern ◽  
Vis Spectroscopy ◽  
Different Temperatures ◽  
Co Precipitation ◽  
Ferromagnetic Ordering ◽  
Mn Concentration ◽  
Mn Doped

In this paper, a systematic investigation has been done to study the effect of variation in annealing temperature on magnetic and optical properties of Mn-doped SnO2. Co-precipitation technique has been used to synthesize Sn1-xMnxO2 samples with low Mn concentration (2 %). Pristine SnO2 is sintered at 350 oC. Mn-doped SnO2 samples are sintered at 350, 450, 550 and 650 oC. The structures of tetragonal rutile of SnO2 and Mn-doped SnO2 have been confirmed by the XRD pattern. Typical ferromagnetic ordering has been observed for Mn-doped SnO2 samples annealed at different temperatures. However, on increasing the annealing temperature saturation magnetization as well as the coercive field decreases, indicating a crucial phase transformation from ferromagnetism to paramagnetism. UV-Vis spectroscopy shows increase in absorbance and a slight shift in the absorption edge with Mn-doping at increasing annealing temperature indicating shifting of absorption peak towards higher wavelength. Tauc’s plot has been used to find the optical band gap (Eg).

Nano Crystalline La Substituted Barium Hexaferrite Synthesized by Coprecipitation Method

2011 ◽  
Vol 264-265 ◽  
pp. 795-800
Author(s):  
Abolghasem Ataie ◽  
S. Moslemi
Keyword(s):  
Annealing Temperature ◽  
Magnetic Phase ◽  
Barium Hexaferrite ◽  
Precipitation Method ◽  
Formation Temperature ◽  
Intermediate Phases ◽  
Nano Crystalline ◽  
La Addition ◽  
Co Precipitation ◽  
Substituted Barium Hexaferrite

La substituted barium hexaferrite Ba1-yFe12LayO19 with 0≤ y ≤0.5 was synthesized by chemical co-precipitation method using aqueous solutions of metallic chlorides at ambient temperature. NaOH was used as a precipitant. The co-precipitated products were annealed at 900 and 1000°C. The effects of La addition on the phase composition, morphology and thermal behavior of samples were studied using XRD, SEM and DTA/TGA, respectively. XRD results indicated that barium hexaferrite forms together with some intermediate phases in samples annealed at 900°C and the amount of intermediate phases decreased significantly by increasing annealing temperature to 1000°C. XRD results also showed that in sample annealed at 1000°C, the crystallite size of magnetic phase decreases from 98 to 64 nm by increasing the amount of La. Thermal analysis (DTA/TGA) implies that formation temperature of barium hexaferrite is increased with addition of La.

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