Electrochemical Capacitive Properties of CuO Nanorods Prepared by a Facile Microwave-Assisted Synthesis Method

2020 ◽  
Vol 62 ◽  
pp. 21-30
Author(s):  
Wei Li ◽  
Na Na Feng
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Precipitation Method ◽  
Microwave Assisted Synthesis ◽  
X Ray ◽  
Microwave Assisted ◽  
Capacitance Performance ◽  
Capacitive Properties ◽  
Cuo Nanorods

CuO nanorods were fabricated by a facile microwave-assisted synthesis method and applied to pseudo-capacitor. The CuO nanorods were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The capacitive behavior of nanorods was investigated by cyclic voltammetry and galvanostatic charge–discharge measurements. Electrochemical experiments reveal that CuO nanorods demonstrate better capacitance performance than granular CuOs prepared by chemical precipitation method. The CuO nanorods have a high specific capacitance of 317 F/g at a current density of 1 A/g and a fairly good cyclic stability.

scholarly journals Efficient Adsorption of Methylene Blue by Porous Biochar Derived from Soybean Dreg Using a One-Pot Synthesis Method

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 661
Author(s):  
Zhiwei Ying ◽  
Xinwei Chen ◽  
He Li ◽  
Xinqi Liu ◽  
Chi Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Urban Pollution ◽  
Maximum Adsorption Capacity ◽  
One Pot ◽  
Average Pore ◽  
X Ray ◽  
Isotherm Equation

Soybean dreg is a by-product of soybean products production, with a large consumption in China. Low utilization value leads to random discarding, which is one of the important sources of urban pollution. In this work, porous biochar was synthesized using a one-pot method and potassium bicarbonate (KHCO3) with low-cost soybean dreg (SD) powder as the carbon precursor to investigating the adsorption of methylene blue (MB). The prepared samples were characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analyzer (EA), Brunauer-Emmett-Teller (BET), X-ray diffractometer (XRD), Raman spectroscopy (Raman), Fourier transform infrared spectrometer (FTIR), and X-ray photoelectron spectroscopy (XPS). The obtained SDB-K-3 showed a high specific surface area of 1620 m2 g−1, a large pore volume of 0.7509 cm3 g−1, and an average pore diameter of 1.859 nm. The results indicated that the maximum adsorption capacity of SDB-K-3 to MB could reach 1273.51 mg g−1 at 318 K. The kinetic data were most consistent with the pseudo-second-order model and the adsorption behavior was more suitable for the Langmuir isotherm equation. This study demonstrated that the porous biochar adsorbent can be prepared from soybean dreg by high value utilization, and it could hold significant potential for dye wastewater treatment in the future.

scholarly journals Synthesis of Ce1−xPdxO2−δ Solid Solution in Molten Nitrate

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 640
Author(s):  
Hideaki Sasaki ◽  
Keisuke Sakamoto ◽  
Masami Mori ◽  
Tatsuaki Sakamoto
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Solid Solutions ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Co Precipitation ◽  
Ionic States

CeO2-based solid solutions in which Pd partially substitutes for Ce attract considerable attention, owing to their high catalytic performances. In this study, the solid solution (Ce1−xPdxO2−δ) with a high Pd content (x ~ 0.2) was synthesized through co-precipitation under oxidative conditions using molten nitrate, and its structure and thermal decomposition were examined. The characteristics of the solid solution, such as the change in a lattice constant, inhibition of sintering, and ionic states, were examined using X-ray diffraction (XRD), scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM−EDS), transmission electron microscopy (TEM)−EDS, and X-ray photoelectron spectroscopy (XPS). The synthesis method proposed in this study appears suitable for the easy preparation of CeO2 solid solutions with a high Pd content.

scholarly journals Photocatalytic degradation of deoxynivalenol over dendritic-like α-Fe2O3 under visible light irradiation

Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 105 ◽  
Author(s):  
Huiting Wang ◽  
Jin Mao ◽  
Zhaowei Zhang ◽  
Qi Zhang ◽  
Liangxiao Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photocatalytic Degradation ◽  
Visible Light Irradiation ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Synthesis Method ◽  
Light Irradiation ◽  
Trichothecene Mycotoxin ◽  
X Ray

Deoxynivalenol (DON) is a secondary metabolite produced by Fusarium, which is a trichothecene mycotoxin. As the main mycotoxin with high toxicity, wheat, barley, corn and their products are susceptible to contamination of DON. Due to the stability of this mycotoxin, traditional methods for DON reduction often require a strong oxidant, high temperature and high pressure with more energy consumption. Therefore, exploring green, efficient and environmentally friendly ways to degrade or reduce DON is a meaningful and challenging issue. Herein, a dendritic-like α-Fe2O3 was successfully prepared using a facile hydrothermal synthesis method at 160 °C, which was systematically characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). It was found that dendritic-like α-Fe2O3 showed superior activity for the photocatalytic degradation of DON in aqueous solution under visible light irradiation (λ > 420 nm) and 90.3% DON (initial concentration of 4.0 μg/mL) could be reduced in 2 h. Most of all, the main possible intermediate products were proposed through high performance liquid chromatography-mass spectrometry (HPLC-MS) after the photocatalytic treatment. This work not only provides a green and promising way to mitigate mycotoxin contamination but also may present useful information for future studies.

scholarly journals Bio-assisted preparation of efficiently architectured nanostructures of γ-Fe2O3 as a molecular recognition platform for simultaneous detection of biomarkers

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Sasikala Sundar ◽  
V. Ganesh
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Photoelectron Spectroscopy ◽  
Simultaneous Detection ◽  
Differential Pulse ◽  
Precipitation Method ◽  
Limit Values ◽  
X Ray ◽  
Co Precipitation ◽  
The Individual

Abstract Magnetic nanoparticles of iron oxide (γ-Fe2O3) have been prepared using bio-assisted method and their application in the field of biosensors is demonstrated. Particularly in this work, different nanostructures of γ-Fe2O3 namely nanospheres (NS), nanograsses (NG) and nanowires (NW) are prepared using a bio-surfactant namely Furostanol Saponin (FS) present in Fenugreek seeds extract through co-precipitation method by following “green” route. Three distinct morphologies of iron oxide nanostructures possessing the same crystal structure, magnetic properties, and varied size distribution are prepared and characterized. The resultant materials are analyzed using field emission scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, vibrating sample magnetometer and Fourier transform infrared spectroscopy. Moreover, the effect of reaction time and concentration of FS on the resultant morphologies of γ-Fe2O3 nanostructures are systematically investigated. Among different shapes, NWs and NSs of γ-Fe2O3 are found to exhibit better sensing behaviour for both the individual and simultaneous electrochemical detection of most popular biomarkers namely dopamine (DA) and uric acid (UA). Electrochemical studies reveal that γ-Fe2O3 NWs showed better sensing characteristics than γ-Fe2O3 NSs and NGs in terms of distinguishable voltammetric signals for DA and UA with enhanced oxidation current values. Differential pulse voltammetric studies exhibit linear dependence on DA and UA concentrations in the range of 0.15–75 µM and 5 μM – 0.15 mM respectively. The detection limit values for DA and UA are determined to be 150 nM and 5 µM. In addition γ-Fe2O3 NWs modified electrode showed higher sensitivity, reduced overpotential along with good selectivity towards the determination of DA and UA even in the presence of other common interferents. Thus the proposed biosensor electrode is very easy to fabricate, eco-friendly, cheaper and possesses higher surface area suggesting the unique structural patterns of γ-Fe2O3 nanostructures to be a promising candidate for electrochemical bio-sensing and biomedical applications.

scholarly journals Synthesis and Characterization of Sr-Doped ZnSe Nanoparticles for Catalytic and Biological Activities

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2189
Author(s):  
V. Beena ◽  
S. L. Rayar ◽  
S. Ajitha ◽  
Awais Ahmad ◽  
Munirah D. Albaqami ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Methyl Orange ◽  
Photoelectron Spectroscopy ◽  
Biological Activities ◽  
Water Remediation ◽  
Precipitation Method ◽  
Znse Nanoparticles ◽  
X Ray ◽  
Degradation Of Methyl Orange

The development of cost-effective and ecofriendly approaches toward water purification and antibacterial activity is a hot research topic in this era. Purposely, strontium-doped zinc selenide (Sr-doped ZnSe) nanoparticles, with different molar ratios of Sr2+ cations (0.01, 0.05, and 0.1), were prepared via the co-precipitation method, in which sodium borohydride (NaBH4) and 2-mercaptoethanol were employed as reducing and stabilizing agents, respectively. The ZnSe cubic structure expanded by Sr2+ cations was indicated by X-ray diffraction (XRD) analysis. The absorption of the chemical compounds on the surface was observed via Fourier transform infrared (FT-IR) spectroscopy. The optical orientation was measured by ultraviolet–visible diffused reflectance spectroscopy (UV-DRS) analysis. The surface area, morphology, and elemental purity were analyzed using field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive spectroscopy (EDS) analyses. The oxidation state and valency of the synthesized nanoparticles were analyzed using X-ray photoelectron spectroscopy (XPS). Sr-doped ZnSe nanoparticles were investigated for photocatalytic degradation of methyl orange (MO), and their antibacterial potential was investigated against different bacterial strains. The antibacterial activity examined against Staphylococcus aureus and Escherichia coli implied the excellent biological activity of the nanoparticles. Moreover, the Sr-doped ZnSe nanoparticles were evaluated by the successful degradation of methyl orange under visible light irradiation. Therefore, Sr-doped ZnSe nanoparticles have tremendous potential in biological and water remediation fields.

scholarly journals Photocatalytic performance of Ag2S/ZnO/ZnS nanocomposites with high visible light response prepared via microwave-assisted hydrothermal two-step method

2018 ◽  
Vol 78 (8) ◽  
pp. 1802-1811 ◽  
Author(s):  
Jiwei Huang ◽  
Changlong Yang ◽  
Qiang Song ◽  
Dongxue Liu ◽  
Li Li
Keyword(s):  
Electron Microscopy ◽  
Visible Light ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Light Response ◽  
Light Sources ◽  
Step Method ◽  
X Ray ◽  
Microwave Assisted ◽  
Visible Light Response

Abstract A series of different ratios of Ag2S/ZnO/ZnS nanocomposites with visible light response were prepared by a microwave-assisted hydrothermal two-step method, whose composition, crystalline structure, morphology and surface physicochemical properties were well-characterized via X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (UV–vis/DRS), photoluminescence spectrum (PL), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) and N2 adsorption–desorption measurements. Results showed that as-composites mainly consisted of ZnS crystal phase, whose grain size increased obviously compared with non Ag2S samples. At the same time, due to the introduction of narrow band gap Ag2S, the synthesized composite can effectively increase the visible optical absorption of ZnO/ZnS composites. Among them, 1% Ag2S/ZnO/ZnS showed a mixed structure of nano-line and nano-particle, of which BET value increased significantly, and the morphology was more excellent. Photocatalytic activities of a series of Ag2S/ZnO/ZnS composites under different light sources were studied using methyl orange as a model molecule, and 1% Ag2S/ZnO/ZnS was taken as the best one. Meanwhile, 1% Ag2S/ZnO/ZnS also showed a good degradation effect on other dyes with different structures, and its degradation efficiency did not change significantly after three cycles, showing certain stability. In addition, composites with Ag2S loading of 1% possessed the highest hydrogen production ability of photolysis water, indicating that the introduction of Ag2S had significantly enhanced the catalytic performance.

Study on the Gas Sensitivity of a CeO2 Based Ceramic Sensing Element: Structure and Characteristic

2007 ◽  
Vol 280-283 ◽  
pp. 305-310
Author(s):  
Tao Yan ◽  
Xiao Lin Liu ◽  
Jian Feng Chen
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Sensing Element ◽  
Gas Sensitivity ◽  
X Ray ◽  
Sensing Properties ◽  
Surface Areas ◽  
Electron Microscopy Analysis

The sensitivity of CuO dispersed on fluorite-type oxide, namely CeO2 was studied in this work. Mixed oxide sample of nanostructured CuxCe1-xO2-y of various composition were generated by step chemical precipitation method. Distinct copper species were identified as a function of copper content by X-ray photoelectron spectroscopy, X-ray powder diffraction, the special surface areas, transmission electron microscopy, scanning electron microscopy analysis, and sensing properties to CO. It was found that only small amounts of copper are sufficient to promote the sensitivity of CeO2 by several orders of magnitude, which excessive amounts of copper (Cu/(Cu+Ce)>0.12) are detrimental to the sensing properties of nanocompositions. The possible causes for this behavior are also discussed.

scholarly journals Development of a nitrogen-doped 2D material for tribological applications in the boundary-lubrication regime

2017 ◽  
Vol 8 ◽  
pp. 1476-1483 ◽  
Author(s):  
Shende Rashmi Chandrabhan ◽  
Velayudhanpillai Jayan ◽  
Somendra Singh Parihar ◽  
Sundara Ramaprabhu
Keyword(s):  
Electron Microscopy ◽  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Large Scale ◽  
Synthesis Method ◽  
Field Trials ◽  
Base Oil ◽  
X Ray ◽  
Nitrogen Doped ◽  
Sliding Mechanism

The present paper describes a facile synthesis method for nitrogen-doped reduced graphene oxide (N-rGO) and the application of N-rGO as an effective additive for improving the tribological properties of base oil. N-rGO has been characterized by different characterization techniques such as X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. N-rGO-based nanolubricants are prepared and their tribological properties are studied using a four-ball tester. The nanolubricants show excellent stability over a period of six months and a significant decrease in coefficient of friction (25%) for small amounts of N-rGO (3 mg/L). The improvement in tribological properties can be attributed to the sliding mechanism of N-rGO accompanied by the high mechanical strength of graphene. Further, the nanolubricant is prepared at large scale (700 liter) and field trials are carried out at one NTPC thermal plant in India. The implementation of the nanolubricant in an induced draft (ID) fan results in the remarkable decrease in the power consumption.

Effect of Zn2+ and F− Co-Modification on the Structure and Electrochemical Performance of Li4Ti5O12 Anode Material

NANO ◽  
2017 ◽  
Vol 12 (05) ◽  
pp. 1750054 ◽  
Author(s):  
Aijia Wei ◽  
Wen Li ◽  
Lihui Zhang ◽  
Xiaohui Li ◽  
Xue Bai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Coating Layer ◽  
Rate Capability ◽  
Precipitation Method ◽  
Charge Capacity ◽  
X Ray ◽  
Modification Process ◽  
Co Precipitation ◽  
A Charge

Zn[Formula: see text] and F[Formula: see text] ions are successfully used to modify pure Li4Ti5O[Formula: see text] via a co-precipitation method followed by calcination at 400[Formula: see text]C for 5[Formula: see text]h in an Ar atmosphere in order to further investigate the reaction mechanism of the fluoride modification process. Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. After the modification process, no ZnF2 coating layer is formed on the surface of Li4Ti5O[Formula: see text], instead, F[Formula: see text] ions react with Li4Ti5O[Formula: see text] to generate a new phase, composed of a small amount of anatase TiO2, rutile TiO2, LiF, and Zn[Formula: see text] ions are suspected to form a ZnO coating layer on Li4Ti5O[Formula: see text] particles. The electrolyte reduction decomposition is suppressed in Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] due to the ZnO coating layer. 1[Formula: see text]wt.% Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] exhibits the best rate capability, which leads to a charge capacity of 236.7, 227.8, 222.1, 202.7, 188.9 and 150.7[Formula: see text]mAh g[Formula: see text] at 0.2C, 0.5C, 1C, 3C, 5C and 10C, respectively, between 0[Formula: see text]V and 3[Formula: see text]V. Furthermore, 1[Formula: see text]wt.% Zn[Formula: see text] and F[Formula: see text] co-modified Li4Ti5O[Formula: see text] exhibits 96.0% charge capacity retention at 3C rate after 200 cycles, which is significantly higher than that of pure Li4Ti5O[Formula: see text] (78.4%).

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