scholarly journals Effect of Time on a Hierarchical Corn Skeleton-Like Composite of CoO@ZnO as Capacitive Electrode Material for High Specific Performance Supercapacitors

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3285 ◽  
Author(s):  
Yedluri Kumar ◽  
Hee-Je Kim
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Xrd Analysis ◽  
Cycling Performance ◽  
Energy Storage Devices ◽  
Tem Analysis ◽  
X Ray ◽  
Potential Applications ◽  
Oxygen Groups

CoO–ZnO-based composites have attracted considerable attention for the development of energy storage devices because of their multifunctional characterization and ease of integration with existing components. This paper reports the synthesis of CoO@ZnO (CZ) nanostructures on Ni foam by the chemical bath deposition (CBD) method for facile and eco-friendly supercapacitor applications. The formation of a CoO@ZnO electrode functioned with cobalt, zinc, nickel and oxygen groups was confirmed by X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), low and high-resolution scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analysis. The as-synthesized hierarchical nanocorn skeleton-like structure of a CoO@ZnO-3h (CZ3h) electrode delivered a higher specific capacitance (Cs) of 1136 F/g at 3 A/g with outstanding cycling performance, showing 98.3% capacitance retention over 3000 cycles in an aqueous 2 M KOH electrolyte solution. This retention was significantly better than that of other prepared electrodes, such as CoO, ZnO, CoO@ZnO-1h (CZ1h), and CoO@ZnO-7h (CZ7h) (274 F/g, 383 F/g, 240 F/g and 537 F/g). This outstanding performance was attributed to the excellent surface morphology of CZ3h, which is responsible for the rapid electron/ion transfer between the electrolyte and the electrode surface area. The enhanced features of the CZ3h electrode highlight potential applications in high performance supercapacitors, solar cells, photocatalysis, and electrocatalysis.

scholarly journals Effect of Time on a Hierarchical Corn Skeleton-Like Composite of CoO@ZnO as Capability Electrode Material for High Specific Performance Supercapacitors

2018 ◽  
Author(s):  
Anil Kumar Yedluri ◽  
Hee-Je Kim
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Energy Storage Devices ◽  
X Ray ◽  
Storage Devices ◽  
Transmission Electron ◽  
Potential Applications ◽  
Oxygen Groups ◽  
Cbd Method

CoO-ZnO-based composites have attracted considerable attention for the development of energy storage devices because of their multifunctional characterization and ease of integration with existing components. This paper reports the synthesis of CoO@ZnO (CZ) nanostructures on Ni foam by the CBD method for facile and eco-friendly supercapacitor applications. The formation of a CoO@ZnO electrode functioned with cobalt, zinc, nickel and oxygen groups was confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, low and high-resolution of scanning electron microscopy, and transmission electron microscopy. The as-synthesized hierarchical nanocorn skeleton-like structure of CoO@ZnO-3h (CZ3h) electrode delivered a higher specific capacitance of 1136 F/g at a current density of 3 A/g with outstanding cycling stability, showing 98.3% capacitance retention over 3000 cycles in an aqueous 2 M KOH electrolyte solution. This retention was significantly better than that of other prepared electrodes, such as CoO (CO), ZnO (ZO), CoO@ZnO-1h (CZ1h), and CoO@ZnO-7h (CZ7h) (274, 383, 240 and 537 F/g, respectively). This superior capacitance was attributed to the ideal surface morphology of CZ3h, which is responsible for the rapid electron/ion transfer between the electrolyte and electrode surface area. The enhanced features of the CZ3h electrode highlight potential applications in high performance supercapacitors, solar cells, photocatalysis, and electrocatalysis.

ZnS NANOFLOWERS ON GRAPHENE FOR USE AS A HIGH-PERFORMANCE PHOTOCATALYST

NANO ◽  
2014 ◽  
Vol 09 (08) ◽  
pp. 1450097 ◽  
Author(s):  
ZENG BIN ◽  
LONG HUI
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Dye Degradation ◽  
Uv Light ◽  
Xps Spectra ◽  
X Ray ◽  
Transmission Electron ◽  
Photocatalytic Activities ◽  
Potential Applications

The nanocomposites of graphene loaded– ZnS nanoflowers (GR– ZnS ) had been successfully prepared. Materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) spectra. A possible formation mechanism of this architecture was proposed. The experimental results revealed that these nanoflowers exhibited excellent UV-light photocatalytic activities for pollutant methyl orange (MO) dye degradation. These new nanostructures were expected to show considerable potential applications in the water treatment.

scholarly journals Synthesis of Three-Dimensional Fe3O4/Graphene Aerogels for the Removal of Arsenic Ions from Water

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yan Ye ◽  
Da Yin ◽  
Bin Wang ◽  
Qingwen Zhang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
3D Structure ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Aerogels ◽  
Transmission Electron ◽  
Potential Applications ◽  
Removal Of Arsenic

We report the synthesis of three-dimensional Fe3O4/graphene aerogels (GAs) and their application for the removal of arsenic (As) ions from water. The morphology and properties of Fe3O4/GAs have been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and superconducting quantum inference device. The 3D nanostructure shows that iron oxide nanoparticles are decorated on graphene with an interconnected network structure. It is found that Fe3O4/GAs own a capacity of As(V) ions adsorption up to 40.048 mg/g due to their remarkable 3D structure and existence of magnetic Fe3O4nanoparticles for separation. The adsorption isotherm matches well with the Langmuir model and kinetic analysis suggests that the adsorption process is pseudo-second-ordered. In addition to the excellent adsorption capability, Fe3O4/GAs can be easily and effectively separated from water, indicating potential applications in water treatment.

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 Ni2P/rGO/NF Nanosheets As a Bifunctional High-Performance Electrocatalyst for Water Splitting

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 744 ◽  
Author(s):  
Jinyu Huang ◽  
Feifei Li ◽  
Baozhong Liu ◽  
Peng Zhang
Keyword(s):  
Electron Microscopy ◽  
Water Splitting ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
High Efficiency ◽  
Splitting Method ◽  
Bifunctional Catalyst ◽  
Strong Activity ◽  
X Ray ◽  
Transmission Electron

The hydrogen generated via the water splitting method is restricted by the high level of theoretical potential exhibited by the anode. The work focuses on synthesizing a bifunctional catalyst with a high efficiency, that is, a nickel phosphide doped with the reduced graphene oxide nanosheets supported on the Ni foam (Ni2P/rGO/NF), via the hydrothermal approach together with the calcination approach specific to the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The Raman, X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscope (TEM), Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HRTEM), as well as elemental mapping, are adopted to study the composition and morphology possessed by Ni2P/rGO/NF. The electrochemical testing is performed by constructing a parallel two-electrode electrolyzer (Ni2P/rGO/NF||Ni2P/rGO/NF). Ni2P/rGO/NF||Ni2P/rGO/NF needs a voltage of only 1.676 V for driving 10 mA/cm2, which is extremely close to Pt/C/NF||IrO2/NF (1.502 V). It is possible to maintain the current density for no less than 30 hours. It can be demonstrated that Ni2P/rGO/NF||Ni2P/rGO/NF has commercial feasibility, relying on the strong activity and high stability.

scholarly journals Nickel Supported on AlCeO3 as a Highly Selective and Stable Catalyst for Hydrogen Production via the Glycerol Steam Reforming Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 411 ◽  
Author(s):  
Nikolaos D. Charisiou ◽  
Georgios I. Siakavelas ◽  
Binlin Dou ◽  
Victor Sebastian ◽  
Steven J. Hinder ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Steam Reforming ◽  
Photoelectron Spectroscopy ◽  
Liquid Product ◽  
Coke Deposition ◽  
Tem Analysis ◽  
X Ray ◽  
Surface Basicity ◽  
Ce Modification ◽  
Temperature Programmed

In this study, a critical comparison between two low metal (Ni) loading catalysts is presented, namely Ni/Al2O3 and Ni/AlCeO3 for the glycerol steam reforming (GSR) reaction. The surface and bulk properties of the catalysts were evaluated using a plethora of techniques, such as N2 adsorption/desorption, Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP–AES), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy / Energy Dispersive X-Ray Spectroscopy (SEM/EDX, Transmission Electron Microscopy (TEM), CO2 and NH3– Temperature Programmed Desorption (TPD), and Temperature Programmed Reduction (H2–TPR). Carbon deposited on the catalyst’s surfaces was probed using Temperature Programmed Oxidation (TPO), SEM, and TEM. It is demonstrated that Ce-modification of Al2O3 induces an increase of the surface basicity and Ni dispersion. These features lead to a higher conversion of glycerol to gaseous products (60% to 80%), particularly H2 and CO2, enhancement of WGS reaction, and a higher resistance to coke deposition. Allyl alcohol was found to be the main liquid product for the Ni/AlCeO3 catalyst, the production of which ceases over 700 °C. It is also highly significant that the Ni/AlCeO3 catalyst demonstrated stable values for H2 yield (2.9–2.3) and selectivity (89–81%), in addition to CO2 (75–67%) and CO (23–29%) selectivity during a (20 h) long time-on-stream study. Following the reaction, SEM/EDX and TEM analysis showed heavy coke deposition over the Ni/Al2O3 catalyst, whereas for the Ni/AlCeO3 catalyst TPO studies showed the formation of more defective coke, the latter being more easily oxidized.

scholarly journals Fabrication of BaTiO3-Loaded Graphene Nanosheets-Based Polyarylene Ether Nitrile Nanocomposites with Enhanced Dielectric and Crystallization Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1667 ◽  
Author(s):  
Shuning Liu ◽  
Chenchen Liu ◽  
Yong You ◽  
Yajie Wang ◽  
Renbo Wei ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Dielectric Constant ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Graphene Nanosheets ◽  
Zinc Phthalocyanine ◽  
Organic Layer ◽  
X Ray ◽  
Polyarylene Ether Nitrile ◽  
Crystallization Properties

In this paper, barium titanate@zinc phthalocyanine (BT@ZnPc) and graphene oxide (GO) hybrids (BT@ZnPc-GO) connected by calcium ions are prepared by electrostatic adsorption, and then introduced into polyarylene ether nitrile (PEN) to obtain composites with enhanced dielectric and crystallization properties. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) results confirm the successful fabrication of the BT@ZnPc-GO. BT@ZnPc-GO and PEN composites (BT@ZnPc-GO/PENs) are obtained through the solution-casting method. BT@ZnPc-GO demonstrates well compatibility with PEN due to its unique structure and the organic layer of ZnPc at the periphery of BT. On the other hand, BT and GO contribute a high dielectric constant of the composites obtained. In addition, the BT@ZnPc-GO can be used as a nucleating agent to promote the crystallization of the nanocomposites. As a result, The BT@ZnPc-GO/PEN exhibits a dielectric constant of 6.4 at 1 kHz and crystallinity of 21.03% after being isothermally treated at 280 °C for 2 h at the GO content of 0.75 wt %. All these results indicate that the hybrid nanofiller BT@ZnPc-GO can be an effective additive for preparing high-performance PEN-based nanocomposites.

scholarly journals Spinel-Type (FeCoCrMnZn)3O4 High-Entropy Oxide: Facile Preparation and Supercapacitor Performance

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5798
Author(s):  
Bingliang Liang ◽  
Yunlong Ai ◽  
Yiliang Wang ◽  
Changhong Liu ◽  
Sheng Ouyang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Nickel Foam ◽  
Spinel Type ◽  
X Ray ◽  
High Entropy ◽  
Transmission Electron ◽  
Coating Method ◽  
Potential Applications ◽  
Supercapacitor Performance

High-entropy oxides (HEOs) have attracted more and more attention because of their unique structures and potential applications. In this work, (FeCoCrMnZn)3O4 HEO powders were synthesized via a facile solid-state reaction route. The confirmation of phase composition, the observation of microstructure, and the analysis of crystal structure, distribution of elements, and valences of elements were conducted by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS), respectively. Furthermore, a (FeCoCrMnZn)3O4/nickel foam ((FeCoCrMnZn)3O4/NF) electrode was prepared via a coating method, followed by the investigation of its supercapacitor performance. The results show that, after calcining (FeCoCrMnZn)3O4 powders at 900 °C for 2 h, a single spinel structure (FCC, Fd-3m, a = 0.8399 nm) was obtained with uniform distribution of Fe, Co, Cr, Mn, and Zn elements, the typical characteristic of a high-entropy oxide. In addition, the mass specific capacitance of the (FeCoCrMnZn)3O4/NF composite electrode was 340.3 F·g−1 (with 1 M KOH as the electrolyte and 1 A·g−1 current density), which indicates that the (FeCoCrMnZn)3O4 HEO can be regarded as a prospective candidate for an electrode material in the field of supercapacitor applications.

SYNTHESIS, CHARACTERIZATION AND THE APPLICABILITY OF β-CYCLODEXTRINS FUNCTIONALIZED MESOPOROUS SBA-15 MOLECULAR SIEVES

NANO ◽  
2013 ◽  
Vol 08 (05) ◽  
pp. 1350050
Author(s):  
MIN GUAN ◽  
HAI-PENG BI ◽  
ZUYUAN WANG ◽  
SHAOHUA BU ◽  
LING HUANG ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Molecular Sieves ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Capacities ◽  
Transmission Electron ◽  
Potential Applications ◽  
Adsorption Desorption

Mesoporous silicas SBA-15 are modified with β-Cyclodextrins (β-CD) by simple grafting method. β-CD functionalized SBA-15 was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), nitrogen adsorption–desorption measurements, thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). Furthermore, the applicability of it is investigated through studying the adsorption properties of clenbuterol. It showed better adsorption capacities of clenbuterol than pure SBA-15. β-CD functionalized SBA-15 material has the potential applications in the treatment of clenbuterol contamination in food and environment science.

scholarly journals Hydrothermal Synthesis of MnWO4@GO Composite as Non-Precious Electrocatalyst for Urea Oxidation

Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 85
Author(s):  
Patnamsetty Chidanandha Nagajyothi ◽  
Kisoo Yoo ◽  
Rajavaram Ramaraghavulu ◽  
Jaesool Shim
Keyword(s):  
Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Photoelectron Spectroscopy ◽  
Xrd Analysis ◽  
Morphological Characterization ◽  
Energy Storage And Conversion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Density Values

In this study, manganese tungstate (MW) and MW/graphene oxide (GO) composites were prepared by a facile hydrothermal synthesis at pH values of 7 and 12. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were used for the structural, compositional, and morphological characterization of the nanoparticles (NPs). The XRD analysis revealed that the formation of monoclinic MnWO4 did not have impurities. The SEM and TEM analyses showed that the synthesized NPs were rod-shaped and well-distributed on the GO. The as-synthesized samples can be used as electrocatalysts for the urea oxidation reaction (UOR). The MW@GO-12 electrocatalyst exhibited higher current density values compared to other electrocatalysts. This study provides a new platform for synthesizing inexpensive nanocomposites as promising electrocatalysts for energy storage and conversion applications.

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