Hydrothermal synthesis and electrochromism of WO3 nanocuboids

RSC Advances ◽  
2014 ◽  
Vol 4 (39) ◽  
pp. 20145-20153 ◽  
Author(s):  
Sangeeta Adhikari ◽  
Debasish Sarkar
Keyword(s):  
Reaction Time ◽  
Hydrothermal Synthesis ◽  
Acid Concentration ◽  
Tungsten Trioxide ◽  
Hydrothermal Reaction ◽  
Processing Parameters ◽  
Important Processing ◽  
Hydrothermal Reaction Time

Tungsten trioxide (WO3) nanocuboids are preferentially developed through control over three important processing parameters: fluoroboric acid concentration, hydrothermal reaction time and temperature.

Influence of hydrothermal reaction time on the supercapacitor performance of Ni-MOF nanostructures

2021 ◽  
Vol 127 (6) ◽  
Author(s):  
M. R. Manikandan ◽  
K. P. Cai ◽  
Y. D. Hu ◽  
C. L. Li ◽  
J. T. Zhang ◽  
...  
Keyword(s):  
Reaction Time ◽  
Hydrothermal Reaction ◽  
Supercapacitor Performance ◽  
Hydrothermal Reaction Time

Effect of hydrothermal dwell time on the diameter-controlled synthesis and magnetic property of MnO2 nanorods

2014 ◽  
Vol 28 (06) ◽  
pp. 1450045 ◽  
Author(s):  
Arbab Mohammad Toufiq ◽  
Fengping Wang ◽  
Qurat-ul-Ain Javed ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Reaction Time ◽  
Dwell Time ◽  
Hydrothermal Reaction ◽  
Ferromagnetic Behavior ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Transmission Electron ◽  
Facile Hydrothermal Route ◽  
Hydrothermal Reaction Time

In this paper, single crystalline 1D tetragonal MnO 2 pen-type nanorods were synthesized by varying the dwell time through a facile hydrothermal route at a reaction temperature of 250°C. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies showed that the diameter of MnO 2 nanorods decreases from 460 nm to 250 nm with the increase in hydrothermal reaction time from 5 h to 15 h. Field-emission scanning electron microscopy (FESEM) and TEM studies revealed the evolution of improved surface morphology of MnO 2 nanorods that are prepared with longer hydrothermal reaction time. The magnetic properties of the products were evaluated using vibrating sample magnetometer (VSM) at room temperature, which showed that the as-prepared samples exhibit weak ferromagnetic behavior. The effect of diameter on the magnetization values was observed and discussed in detail.

Facile Hydrothermal Synthesis of Molybdenum Disulfide (MoS2) as Advanced Electrodes for Super Capacitors Applications

MRS Advances ◽  
2016 ◽  
Vol 1 (45) ◽  
pp. 3089-3097 ◽  
Author(s):  
H. Adhikari ◽  
C. Ranaweera ◽  
R. Gupta ◽  
S. R. Mishra
Keyword(s):  
Reaction Time ◽  
Electrochemical Properties ◽  
Molybdenum Disulfide ◽  
Electrode Materials ◽  
Hydrothermal Reaction ◽  
Three Dimensional ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Supercapacitor Applications ◽  
Hydrothermal Reaction Time

ABSTRACTA facile hydrothermal method was used to synthesize molybdenum disulfide (MoS2) microspheres. The effect of hydrothermal reaction time on morphology and electrochemical properties of MoS2 microspheres was evaluated. X-ray diffraction showed presence of crystalline MoS2 structure, where content of crystalline phase was observed to increase with hydrothermal reaction time. Electrochemical properties of MoS2 were evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge in 3M KOH solution. Specific capacitance of nanostructured MoS2 was observed to be between 68 F/g and 346 F/g at different scan rates along with excellent cyclic stability. High power density (∼1200 W/kg) and energy density (∼5 Wh/kg) was observed for MoS2 sample synthesized for 24 hours of hydrothermal reaction time. Overall optimal electrocapactive performance was observed for sample prepared for 24 hours of reaction time. It is demonstrated that the obtained MoS2 microspheres with three-dimensional architecture has excellent electrochemical performances as electrode materials for supercapacitor applications.

Effect of Hydrothermal Reaction Time on Electrical, Structural and Magnetic Properties of Cobalt Ferrite

2020 ◽  
Vol 234 (2) ◽  
pp. 323-353 ◽  
Author(s):  
Farzana Majid ◽  
Amarah Nazir ◽  
Sadia Ata ◽  
Ismat Bibi ◽  
Hafiz Shahid Mehmood ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Reaction Time ◽  
Cobalt Ferrite ◽  
Hydrothermal Reaction ◽  
Spinel Ferrite ◽  
Uniaxial Anisotropy ◽  
Tangent Loss ◽  
Hydrothermal Route ◽  
X Ray ◽  
Hydrothermal Reaction Time

AbstractCobalt ferrite was synthesized by hydrothermal route in order to investigate the effect of hydrothermal reaction time on structural, magnetic and dielectric properties. The synthesized cobalt ferrite was characterized by X-ray diffraction, Fourier transform infrared and Vibrating-Sample Magnetometer (VMS). XRD data analysis confirmed the formation of cubic inverse spinel ferrite for complete time series as the high intensity peak corresponds to cubic normal spinel structure. The ionic radii, cation distribution among tetrahedral and octahedral sites, lattice parameters, X-ray density, bond lengths were also investigated cobalt ferrite prepared at different hydrothermal reaction time. The crystallite size was found to be in the range of 11.79–32.78 nm. Tolerance factor was near unity that also confirms the formation of cubic ferrites. VSM studies revealed the magnetic nature of cobalt ferrite. The coercivity (1076.3Oe) was observed for a sample treated for 11 h. The squareness ratio was 0.56 that is close to 0.5 which shows uniaxial anisotropy in cobalt ferrite. Frequency dependent dielectric properties i.e. dielectric constant, AC conductivity, tangent loss and AC resistivity are calculated with the help of Impedance Analyzer. Intrinsic cation vibration of cubic spinel ferrites are confirmed from FTIR analysis in the range of 400–4000 cm−1. In view of enhanced properties, this technique could possibly be used for the synthesis of cobalt ferrite for different applications.

Preparation of Ba3In2(OH)12 and its Photocatalytic Performance

2016 ◽  
Vol 852 ◽  
pp. 618-625
Author(s):  
Qin Ku Zhang ◽  
Bing Hua Yao
Keyword(s):  
Photocatalytic Activity ◽  
Reaction Time ◽  
Hydrothermal Method ◽  
Reaction Temperature ◽  
Hydrothermal Reaction ◽  
Solar Irradiation ◽  
Evolution Rate ◽  
Molar Ratio ◽  
Ternary Oxide ◽  
Hydrothermal Reaction Time

Hydrogarnet Ba3In2(OH)12 was synthesized by hydrothermal method from raw materials Ba(NO3)2 and In(OH)3. The obtained sample was characterized by X-ray diffraction (XRD), scanning electron microscope(SEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS) and N2 adsorption-desorption isotherms (BET). Photocatalyitc activity was tested via rhodamine B(RhB) degradation as the modle pollutant. The influence of hydrothermal reaction temperature (T), hydrothermal reaction time (t), Ba/In molar ratio(Ba/In), and NaOH concentration(Cg) on the photocatalytic activity of Ba3In2(OH)12 were investigated. The results showed that the synthetic Ba3In2(OH)12 exhibited highest photocatalytic activity under the optimum hydrothermal reaction conditions of T=200°C, t=14 h, Ba/In=2:1 and Cg=7 mol/L. RhB can be completely mineralized by Ba3In2(OH)12 under 125 W mercury light irradiation for 3 hours. There are many scholars and experts engaged in the research of various types of photocatalytic materials and applied in the degradation of environmental pollutants in the last 40 years. Such as, the oxide of In2O3[1], ZnO, TiO2 et al. The ternary oxide of indium, molybdate, tungstate and vanadate et al. New type quaternary metal oxide. In the past 20 years, indium-based semiconductor material were got rapid development in the field of display, laser, microwave devices, light-emitting diodes and photocatalyst because of which had good gas sensitivity, heat sensitivity, photosensitivity and other characteristics. CaIn2O4 was synthesized using self-propagating high-temperature sysnthesis method[2]. RhB can be absolutely mineralized under solar irradiation for 2 hours. The g-C3N4/CaIn2O4 composite was synthesized using facile solvothermal method[3]. The g-C3N4/CaIn2O4 composite reached a high H2 evolution rate of 62.5 μmol/h from CH3OH/ H2O solution when the content of grapheme was 1wt%. Furthermore, the 1wt% g-C3N4/CaIn2O4 composite did not show deactivation for H2 evolution for longer than 32 h. The core-shell like composite In2O3@Ba2In2O5 was synthesized via chemical impregnation method with sample calcination[4]. It degraded 100% of the MB in 30 min compared with P-25, which degraded 100% of the MB in 120 min. C-CdIn2O4 nanoparticle was synthesized by sol-gel templating method[5]. Natural sunlight illumination experiments showed the H2 evolution rate of C-CdIn2O4 was 17 μmol/h as compared to 2.1 μmol/h for the Pt:TiO2. Hydrogarnet Ba3In2(OH)12 was first described by Kwestroo et al in 1977, who used the prolonged refluxing of BaCl2 and In2O3 in 12 mol/L NaOH at 110°C[6]. The pure Ba3In2(OH)12 was prepared by first preparing pure Ba3In2O6 by prolonged reaction of stoichiometric amounts of BaCO3 and In2O3 at 1300 °C. Then, the pure Ba3In2O6 was reacted with 12 mol/L NaOH at 85 °C for 12 hours under a pure nitrogen atmosphere[7]. Hydrogarnet Ba3In2(OH)12 was synthesized by hydrothermal method, using In(OH)3, Ba(NO3)2 and NaOH. With RhB as a model degradation pollutant, the influence of hydrothermal reaction temperature, hydrothermal reaction time, Ba/In molar ratio and NaOH concentration on the photocatalytic activity of Ba3In2(OH)12 were investigated and the photocatalytic degradation mechanism of RhB were investigated. The results can provide references for the research and application of this material system in the future.

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