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 ◽  
...  

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.

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 418 ◽  
Author(s):  
Shuning Liu ◽  
Chenchen Liu ◽  
Changyu Liu ◽  
Ling Tu ◽  
Yong You ◽  
...  

Barium titanate (BT) and polyarylene ether nitrile (PEN) nanocomposites with enhanced dielectric properties were obtained by using carboxylatedzinc phthalocyanine (ZnPc-COOH) buffer as the plasticizer. Carboxylated zinc phthalocyanine, prepared through hydrolyzing ZnPc in NaOH solution, reacted with the hydroxyl groups on the peripheral of hydrogen peroxide treated BT (BT-OH) yielding core-shell structured BT@ZnPc. Thermogravimetric analysis (TGA), transmission electron microscopy (TEM), TEM energy dispersive spectrometer mapping, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) demonstrated successful preparation of BT@ZnPc. The fabricated BT@ZnPc was incorporated into the PEN matrix through the solution casting method. Rheological measurements demonstrated that the ZnPc-COOH buffer can improve the compatibility between BT and PEN effectively. With the existence of the ZnPc-COOH buffer, the prepared BT@ZnPc/PEN nanocomposites exhibit a high dielectric constant of 5.94 and low dielectric loss (0.016 at 1000 Hz). BT@ZnPc/PEN dielectric composite films can be easily prepared, presenting great application prospects in the field of organic film capacitors.


Toxins ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 105 ◽  
Author(s):  
Huiting Wang ◽  
Jin Mao ◽  
Zhaowei Zhang ◽  
Qi Zhang ◽  
Liangxiao Zhang ◽  
...  

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.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 744 ◽  
Author(s):  
Jinyu Huang ◽  
Feifei Li ◽  
Baozhong Liu ◽  
Peng Zhang

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.


Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 445 ◽  
Author(s):  
Xiangfeng Guan ◽  
Yongjing Wang ◽  
Peihui Luo ◽  
Yunlong Yu ◽  
Dagui Chen ◽  
...  

The development of high-performance acetone gas sensor is of great significance for environmental protection and personal safety. SnO2 has been intensively applied in chemical sensing areas, because of its low cost, high mobility of electrons, and good chemical stability. Herein, we incorporated nitrogen atoms into the SnO2 nanostructure by simple solvothermal and subsequent calcination to improve gas sensing property for acetone. The crystallization, morphology, element composition, and microstructure of as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), Raman spectroscopy, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and the Brunauer–Emmett–Teller (BET) method. It has been found that N-incorporating resulted in decreased crystallite size, reduced band-gap width, increased surface oxygen vacancies, enlarged surface area, and narrowed pore size distribution. When evaluated as gas sensor, nitrogen-incorporated SnO2 nanostructure exhibited excellent sensitivity for acetone gas at the optimal operating temperature of 300 °C with high sensor response (Rair/Rgas − 1 = 357) and low limit of detection (7 ppb). The nitrogen-incorporated SnO2 gas sensor shows a good selectivity to acetone in the interfering gases of benzene, toluene, ethylbenzene, hydrogen, and methane. Furthermore, the possible gas-sensing mechanism of N-incorporated SnO2 toward acetone has been carefully discussed.


NANO ◽  
2014 ◽  
Vol 09 (08) ◽  
pp. 1450097 ◽  
Author(s):  
ZENG BIN ◽  
LONG HUI

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.


2015 ◽  
Vol 16 (2) ◽  
pp. 289-292
Author(s):  
B.I. Ilkiv ◽  
S.S. Petrovska ◽  
R.A. Sergienko ◽  
О.О. Foya ◽  
O.V. Ilkiv ◽  
...  

Investigations of graphene nanosheets and oxidized graphene nanosheets were carried out using X-ray photoelectron spectroscopy. Scanning and transmission electron microscopy investigations were used in addition to X-ray photoelectron spectroscopy. It was found that functional carboxyl and epoxide groups were removed from samples due to argon bombardment in studies of oxidized graphene nanosheets with X-ray photoelectron spectroscopy. Thus the ОKα-band was not revealed in oxidized graphene nanosheets owing to oxygen removal due to electron bombardment with the use of. ultra-soft X-ray emission spectroscopy. 


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3285 ◽  
Author(s):  
Yedluri Kumar ◽  
Hee-Je Kim

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.


Author(s):  
Anil Kumar Yedluri ◽  
Hee-Je Kim

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.


2021 ◽  
Vol 21 (7) ◽  
pp. 3903-3908
Author(s):  
Inhan Kang ◽  
Jungwon Kang

Lithium–oxygen (Li–O2) batteries are considered as a promising high-energy storage system. However, they suffer from overpotential and low energy efficiency. This study showed that CuO growth on carbon using facile synthesis (simple dipping and heating process) reduces overpotential, thus increasing the energy efficiency. We confirmed the structure of CuO on carbon using X-ray diffraction pattern, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, and field-emission transmission electron microscopy. The cathode of CuO on carbon shows an average overpotential reduction of ˜6% charge/discharge during 10 cycles in nonaqueous Li–O2 batteries. The possible reason for the reduced charge overpotential of the cathode of CuO on carbon is attributed to the formed Li2O2 of smaller particle size during discharging compared to pristine carbon.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2816
Author(s):  
Javed Iqbal ◽  
Arshid Numan ◽  
Mohammad Omaish Ansari ◽  
Rashida Jafer ◽  
Priyanka R. Jagadish ◽  
...  

In this study, silver (Ag) and cobalt oxide (Co3O4) decorated polyaniline (PANI) fibers were prepared by the combination of in-situ aniline oxidative polymerization and the hydrothermal methodology. The morphology of the prepared Ag/Co3O4@PANI ternary nanocomposite was studied by scanning electron microscopy and transmission electron microscopy, while the structural studies were carried out by X-ray diffraction and X-ray photoelectron spectroscopy. The morphological characterization revealed fibrous shaped PANI, coated with Ag and Co3O4 nanograins, while the structural studies revealed high purity, good crystallinity, and slight interactions among the constituents of the Ag/Co3O4@PANI ternary nanocomposite. The electrochemical performance studies revealed the enhanced performance of the Ag/Co3O4@PANI nanocomposite due to the synergistic/additional effect of Ag, Co3O4 and PANI compared to pure PANI and Co3O4@PANI. The addition of the Ag and Co3O4 provided an extended site for faradaic reactions leading to the high specific capacity. The Ag/Co3O4@PANI ternary nanocomposite exhibited an excellent specific capacity of 262.62 C g−1 at a scan rate of 3 mV s−1. The maximum energy and power density were found to be 14.01 Wh kg−1 and 165.00 W kg−1, respectively. The cyclic stability of supercapattery (Ag/Co3O4@PANI//activated carbon) consisting of a battery type electrode demonstrated a gradual increase in specific capacity with a continuous charge–discharge cycle until ~1000 cycles, then remained stable until 2500 cycles and later started decreasing, thereby showing the cyclic stability of 121.03% of its initial value after 3500 cycles.


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