scholarly journals Synthesis and Characterization of PVA-Assisted Metal Oxide Nanomaterials: Surface Area, Porosity, and Electrochemical Property Improvement

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Buzuayehu Abebe ◽  
H. C. Ananda Murthy ◽  
Enyew Amare Zereffa ◽  
You Qiang
Keyword(s):  
Charge Transfer ◽  
Metal Oxide ◽  
Surface Area ◽  
Electrochemical Property ◽  
Sol Gel ◽  
Volume Ratio ◽  
Poly Vinyl Alcohol ◽  
Tem Analysis ◽  
Transfer Resistance ◽  
Transfer Capability

The poly(vinyl alcohol)-assisted sol-gel-self-propagation route has been used for the synthesis of porous binary metal oxide nanocomposites (BMONCs) and ternary metal oxide nanocomposites (TMONCs). The effects of synthesis techniques, precursor’s type, amount of PVA loading, and precursor’s percentage were studied. The optical, chemical bonding, crystallinity, morphological, textural, and electrochemical properties of the synthesized materials were characterized by UV-vis-DRS/UV-vis, FT-IR, XRD, SEM/EDX and TEM/HRTEM/SAED, BET, and CV/EIS techniques, respectively. The porous nature of the materials was confirmed by SEM, BET, and SAED analytical techniques. Using XRD and TEM analysis, the approximate particle size of the materials was confirmed to be in the nanometer range (~7-70 nm). The EDX and HRTEM analysis was confirming the presence of predictable composition and actuality of the composites, respectively. Moving from bare ZnO to ternary nanocomposites, the great morphological, surface area, and electrochemical property enhancement was confirmed. The charge transfer capability order was obtained to be ZnO/Fe2O3/Mn2O3 > ZnO/Fe2O3 > ZnO/Mn2O3 > ZnO. The respective approximate electron transfer resistance value is 7, 25, 61, and 65 Ω. Therefore, this work can improve the toxicity towards solvent used, surface area to volume ratio, and aggregation/agglomeration problem and also enhance the charge transfer capability due to the heterojunction.

scholarly journals Multifunctional application of PVA-aided Zn–Fe–Mn coupled oxide nanocomposite

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Buzuayehu Abebe ◽  
H. C. Ananda Murthy ◽  
Enyew Amare Zereffa
Keyword(s):  
Charge Transfer ◽  
Analytical Techniques ◽  
Antibacterial Activities ◽  
Poly Vinyl Alcohol ◽  
Blue Dye ◽  
Ternary Oxide ◽  
Gram Positive Bacteria ◽  
Transfer Capability ◽  
Ft Ir ◽  
Synthesized Materials

AbstractZinc oxide (ZnO) is a fascinating semiconductor material with many applications such as adsorption, photocatalysis, sensor, and antibacterial activities. By using a poly (vinyl alcohol) (PVA) polymer as a capping agent and metal oxides (iron and manganese) as a couple, the porous PVA-aided Zn/Fe/Mn ternary oxide nanocomposite material (PTMO-NCM) was synthesized. The thermal, optical, crystallinity, chemical bonding, porosity, morphological, charge transfer properties of the synthesized materials were confirmed by DTG/DSC, UV–Vis-DRS, XRD, FT-IR, BET, SEM-EDAX/TEM-HRTEM-SAED, and CV/EIS/amperometric analytical techniques, respectively. The PTMO-NCM showed an enhanced surface area and charge transfer capability, compared to ZnO. Using the XRD pattern and TEM image analysis, the crystalline size of the materials was confirmed to be in the nanometer range. The porosity and superior charge transfer capabilities of the PTMO-NCM were confirmed from the BET, HRTEM (IFFT)/SAED, and CV/EIS analysis. The adsorption kinetics (adsorption reaction/adsorption diffusion) and adsorption isotherm test confirmed the presence of a chemisorption type of adsorbate/methylene blue dye-adsorbent/PTMO-NCM interaction. The photocatalytic performance was tested on the Congo red and Acid Orange-8 dyes. The superior ascorbic acid sensing capability of the material was understood from CV and amperometric analysis. The noble antibacterial activities of the material were also confirmed on both gram-negative and gram-positive bacteria.

scholarly journals Effect of nanostructured carbon coatings on the electrochemical performance of Li1.4Ni0.5Mn0.5O2+ x -based cathode materials

2016 ◽  
Vol 7 ◽  
pp. 1960-1970 ◽  
Author(s):  
Konstantin A Kurilenko ◽  
Oleg A Shlyakhtin ◽  
Oleg A Brylev ◽  
Dmitry I Petukhov ◽  
Alexey V Garshev
Keyword(s):  
Diffusion Coefficient ◽  
Charge Transfer ◽  
Specific Capacity ◽  
Charge Transfer Resistance ◽  
Poly Vinyl Alcohol ◽  
Nanostructured Carbon ◽  
Transfer Resistance ◽  
Carbon Coatings ◽  
Lithium Diffusion Coefficient ◽  
Electrochemical Cycling

Nanocomposites of Li1.4Ni0.5Mn0.5O2+ x and amorphous carbon were obtained by the pyrolysis of linear and cross-linked poly(vinyl alcohol) (PVA) in presence of Li1.4Ni0.5Mn0.5O2+ x . In the case of linear PVA, the formation of nanostructured carbon coatings on Li1.4Ni0.5Mn0.5O2+ x particles is observed, while for cross-linked PVA islands of mesoporous carbon are located on the boundaries of Li1.4Ni0.5Mn0.5O2+ x particles. The presence of the carbon framework leads to a decrease of the polarization upon cycling and of the charge transfer resistance and to an increase in the apparent Li+ diffusion coefficient from 10−16 cm2·s−1 (pure Li1.4Ni0.5Mn0.5O2+ x ) to 10−13 cm2·s−1. The nanosized carbon coatings also reduce the deep electrochemical degradation of Li1.4Ni0.5Mn0.5O2+ x during electrochemical cycling. The nanocomposite obtained by the pyrolysis of linear PVA demonstrates higher values of the apparent lithium diffusion coefficient, a higher specific capacity and lower values of charge transfer resistance, which can be related to the more uniform carbon coatings and to the significant content of sp2-hybridized carbon detected by XPS and by Raman spectroscopy.

Application of Nanometer Metal Oxides in Infrared Ray Shielding Transparent Thin Film

2011 ◽  
Vol 474-476 ◽  
pp. 195-199 ◽  
Author(s):  
Ai Hong Guo ◽  
Xue Jiao Tang ◽  
Su Juan Zhang
Keyword(s):  
Thin Film ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Sol Gel ◽  
Volume Ratio ◽  
Experimental Results ◽  
Mass Ratio ◽  
Gel Method ◽  
Water Based ◽  
Better Than

Water-based infrared ray shielding coating, that is, nanometer metal oxide is added to the water-based paint, which has anti-IR features without affecting the transparency of the paint. In this paper, the nanometer oxides are prepared by sol-gel method, added into polypropylene sour. In order to improve the infrared ray shielding of the thin film, two kinds of nanometer oxides are added into the polypropylene sour with different volume ratios, the shielding performance of the paint is studied. Experimental results show: in the 8000 ~ 4000cm-1 range, the transmittances of infrared ray is 30% to 75%; in 4000 ~ 400cm-1 range, transmittances decrease significantly; 3% ZnO, 3% Fe2O3, 3% Y2O3, 2% Al2O3 are the best mass ratio of every single nanometer oxide; the infrared shielding rate of Fe2O3 and Y2O3 mixture with the volume ratio of 1 to 4 is better than Fe2O3 and Y2O3 single.

SYNTHESIS AND MICROSTRUCTURE OF A NOVEL TiO2 AEROGEL–TiO2 NANOWIRE COMPOSITE

NANO ◽  
2008 ◽  
Vol 03 (05) ◽  
pp. 373-379 ◽  
Author(s):  
YOSHIKAZU SUZUKI ◽  
MARIE-HÉLÈNE BERGER ◽  
DANIELA D'ELIA ◽  
PIERRE ILBIZIAN ◽  
CHRISTIAN BEAUGER ◽  
...  
Keyword(s):  
Surface Area ◽  
Network Structure ◽  
Sol Gel ◽  
Hydrothermal Process ◽  
Supercritical Drying ◽  
Large Surface Area ◽  
Tem Analysis ◽  
Tio2 Nanowire ◽  
Nanowire Network ◽  
Gel Technique

TiO 2 aerogel–10 mol% TiO 2 nanowire composite was prepared by a sol–gel technique with the addition of TiO 2 nanowires to TiO 2 sol, followed by supercritical drying in CO 2. TiO 2 nanowires (anatase with minor rutile phases) as dispersoid were prepared by a hydrothermal process followed by calcination in air at 600°C. The TiO 2 nanowires were dispersed in a 2-propanol/ H 2 O / HNO 3 solution, and the mixture was added drop by drop to a tetrabutyl orthotitanate [i.e. Ti (IV) n-butoxide] solution in 2-propanol. After gelation, the TiO 2 alcogel– TiO 2 nanowire composite was dried in supercritical CO 2 to obtain the final, TiO 2 aerogel– TiO 2 nanowire composite. TEM analysis revealed that a unique "nanowire network" structure was formed within the mesoporous aerogel matrix. The aerogel– TiO 2 nanowire composite had a relatively large surface area 427 m2/g, with mesopores ~ 16 nm in diameter and a pore of volume of 1.63 cm3/g.

scholarly journals The Effect of Plasticizers on the Polypyrrole-Poly(vinyl alcohol)-Based Conducting Polymer Electrolyte and Its Application in Semi-Transparent Dye-Sensitized Solar Cells

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 791
Author(s):  
KM Manikandan ◽  
Arunagiri Yelilarasi ◽  
SS Saravanakumar ◽  
Raed H. Althomali ◽  
Anish Khan ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Polymer Electrolyte ◽  
Vinyl Alcohol ◽  
Ethylene Carbonate ◽  
Dye Sensitized Solar Cells ◽  
Charge Transfer Resistance ◽  
Poly Vinyl Alcohol ◽  
Average Roughness ◽  
Transfer Resistance ◽  
Doped Polymer

In this work, the quasi-solid-state polymer electrolyte containing poly(vinyl alcohol)-polypyrrole as a polymer host, potassium iodide (KI), iodine (I2), and different plasticizers (EC, PC, GBL, and DBP) was successfully prepared via the solution casting technique. Fourier transform infrared spectroscopy (FTIR) was used to analyze the interaction between the polymer and the plasticizer. X-ray diffraction confirmed the reduction of crystallinity in the polymer electrolyte by plasticizer doping. The ethylene carbonate-based polymer electrolyte showed maximum electrical conductivity of 0.496 S cm−1. The lowest activation energy of 0.863 kJ mol−1 was obtained for the EC-doped polymer electrolyte. The lowest charge transfer resistance Rct1 was due to a faster charge transfer at the counter electrode/electrolyte interface. The polymer electrolyte containing the EC plasticizer exhibited an average roughness of 23.918 nm. A photo-conversion efficiency of 4.19% was recorded in the DSSC with the EC-doped polymer electrolyte under the illumination of 100 mWcm−2.

Synthesis of Pseudoboehmite - Aging Effect

2019 ◽  
Vol 958 ◽  
pp. 5-10
Author(s):  
Antonio Hortencio Munhoz Jr. ◽  
Renato Meneghetti Peres ◽  
Leila Figueiredo Miranda ◽  
Raphael Cons Andrades ◽  
Matheus Francelino Bezerra da Silva ◽  
...  
Keyword(s):  
Surface Area ◽  
High Purity ◽  
Sol Gel ◽  
Aging Effect ◽  
High Specific Surface Area ◽  
Poly Vinyl Alcohol ◽  
Gamma Alumina ◽  
Aluminum Compound ◽  
Molecular Precursors ◽  
Sol Gel Process

The Pseudoboehmite is an aluminum compound used as an alumina precursor and it is produced by sol-gel process. The sol-gel process is a methodology to produce porous, vitreous or crystalline ceramics started by molecular precursors. Pseudoboehmite with high purity, high specific surface area and porous homogeneity was obtained by sol-gel process. The material was used to produce gamma-alumina with surface area ranging from 211.2-288.1m2/g. It was studied the effect of aging time, temperature of aging and poly (vinyl alcohol) addition in the synthesis.

scholarly journals Structural refinement and electrochemical properties of one dimensional (ZnO NRs)1−x(CNs)x functional hybrids for serotonin sensing studies

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sajid B. Mullani ◽  
Ananta G. Dhodamani ◽  
Annadanesh Shellikeri ◽  
Navaj B. Mullani ◽  
Anita K. Tawade ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electrochemical Properties ◽  
Surface Area ◽  
Limit Of Detection ◽  
Zno Nanorods ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Bet Analysis ◽  
Lower Charge ◽  
Lower Charge Transfer Resistance

Abstract Herein, the efficient serotonin (5-HT) sensing studies have been conducted using the (ZnO NRs)1−x(CNs)x nanocomposites (NCs) having appropriate structural and electrochemical properties. Initially, the different compositions of ZnO nanorods (NRs), with varying content of carbon nanostructures (CNs=MWCNTs and RGO), are prepared using simple in-situ wet chemical method and thereafter these NCs have been characterized for physico-chemical properties in correlation to the 5-HT sensing activity. XRD Rietveld refinement studies reveal the hexagonal Wurtzite ZnO NRs oriented in (101) direction with space group ‘P63mc’ and both orientation as well as phase of ZnO NRs are also retained in the NCs due to the small content of CNs. The interconnectivity between the ZnO NRs with CNs through different functional moieties is also studied using FTIR analysis; while phases of the constituents are confirmed through Raman analysis. FESEM images of the bare/NCs show hexagonal shaped rods with higher aspect ratio (4.87) to that of others. BET analysis and EIS measurements reveal the higher surface area (97.895 m2/g), lower charge transfer resistance (16.2 kΩ) for the ZCNT 0.1 NCs to that of other NCs or bare material. Thereafter, the prepared NCs are deposited on the screen printed carbon electrode (SPCE) using chitosan as cross-linked agent for 5-HT sensing studies; conducted through cyclic voltammetry (CV) and square wave voltammetry (SWV) measurements. Among the various composites, ZCNT0.1 NCs based electrodes exhibit higher sensing activity towards 5-HT in accordance to its higher surface area, lower particle size and lower charge transfer resistance. SWV measurements provide a wide linear response range (7.5–300 μM); lower limit of detection (0.66 μM), excellent limit of quantification (2.19 μM) and good reproducibility to ZCNT 0.1 NCs as compared to others for 5-HT sensing studies.

Study on Reverse Micro emulsion Method Applied in Preparation of Catalyst MnBaAl11O19-δ for Dimethyl Ether Combustion

2010 ◽  
Vol 148-149 ◽  
pp. 1532-1537
Author(s):  
Qian Yu ◽  
Lin Yu ◽  
Gui Qiang Diao ◽  
Ming Sun ◽  
Ying Min Huang ◽  
...  
Keyword(s):  
High Activity ◽  
Surface Area ◽  
Dimethyl Ether ◽  
Sol Gel ◽  
Volume Ratio ◽  
Large Surface Area ◽  
Precipitation Method ◽  
Water Volume ◽  
Emulsion Method ◽  
Micro Emulsion

Reverse micro emulsion method showed some advantages in the preparation of the catalyst MnBaAl11O19-δ with large surface area and high activity, when compared with sol-gel method or co-precipitation method. The influences of water content in reverse micro emulsion on nanostructure catalyst MnBaAl11O19-δ were discussed in this paper. The catalyst MnBaAl11O19-δ was prepared by reverse microemulsion method with a system consisted of 55% of n-heptane, 15% of emulsifier OP-10, 15% of 1-octanol and 15% of water (volume ratio). It resulted in the catalyst a length of 10-30nm plated-like phase and large surface area of 106 m2/g. The catalyst was applied in dimethyl ether combustion and it showed high activity with T10% at 160 °C and T90% at 300 °C. The recycle reverse micro emulsion was reused to prepare the catalyst MnBaAl11O19-δ. The catalyst MnBaAl11O19-δ prepared with that, still showed large surface area of 65m2/g and high activity with T10% at 170 °C and T90% at 320 °C in dimethyl ether catalytic combustion.

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