Electrochemical Performance of Iron and Cobalt Tetrapyrazinoporphyrazines Supported on Multiwalled Carbon Nanotubes

2013 ◽  
Vol 634-638 ◽  
pp. 2155-2159 ◽  
Author(s):  
Sen Liu ◽  
Jin Hua Lu ◽  
He Jun Li ◽  
Ying Bo Fei

Iron tetrapyrazinoporphyrazine (FePTpz) and cobalt tetrapyrazinoporphyrazines (CoPTpz) supported on multiwalled carbon nanotubes (MWCNTs) are prepared by solid phase synthesis method. The products are characterized by scanning and transmission electron microscopy. The electrocatalytic activity of the obtained MWCNTs-supported FePTpz and CoPTpz assemblies (MPTpz/MWCNTs) is measured by cyclic voltammetry and rotating disk electrode techniques in an oxygen-saturated 0.1M KOH. The results show that MPTpz/MWCNTs are more efficient than reference MPTpz. FePTpz/MWCNTs are more efficient for O2 reduction than CoPTpz/MWCNTs, both of FePTpz/MWCNTs and CoPTpz/MWCNTs exhibit a one-step, four-electron pathway for ORR.

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Liu ◽  
Chunli Guo ◽  
Xiaojian Ma ◽  
Changhui Sun ◽  
Fengxia Li ◽  
...  

Multiwalled carbon nanotubes filled with MgO nanorods were synthesized through the reaction of ethanol and Mg powder in the presence ofTiO2at 400C°. X-ray powder diffraction indicated that the sample was composed of graphite and cubic MgO. Transmission electron microscopy studies showed that multi-walled CNTs with the outer diameters of 70–130 nm were filled with discontinuous MgO nanorods whose diameter was in the range of 25–40 nm. The ratios of the band intensities(ID/IG=0.67)in Raman spectrum implied that carbon nanotubes had good crystallinity. The influence of correlative reaction factors on the morphology of the sample and the possible formation mechanism were discussed.


2015 ◽  
Vol 1094 ◽  
pp. 222-228
Author(s):  
Lei Zhou ◽  
Da Wei He ◽  
Hong Lu Wu ◽  
Zeng Hui Qiu

A facile synthesis method of three dimensional reduced graphene oxide (RGO)/multiwalled carbon nanotubes (MWCNTs) hydrogel was introduced. Hydrogel samples which were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM) and examined by X-ray diffraction (XRD) have been used as the electrode of supercapacitor. Cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) were used to investigate the Supercapacitors which we have fabricated. Because MWCNTs inserting into layers of RGO homogeneously prevent the layers of RGO from stacking and enlarge the specific surface area of graphene, the specific capacitance of RGO/MWCNTs material has been greatly improved. At the current density of 0.2A/g, the specific capacitance of RGO/MWCNTs electrode is about 176F/g, which means a 52% increasement compared to which of pure RGO material electrode. And the specific capacitance of RGO/MWCNTs also achieves a good rate property.


2013 ◽  
Vol 706-708 ◽  
pp. 15-19 ◽  
Author(s):  
Feng Ying Chen ◽  
Ke Zhi Li ◽  
He Jun Li

Acid-functionalized multiwalled carbon nanotube (AF-MWCNT)-supported tetranitro-copper phthalocyanine (TNCuPc) assemblies were prepared by solid phase synthesis method. The products were characterized by infrared spectroscopy, scanning electron microscopy and XRD. The electrocatalytic activity of the obtained AF-MWCNT-supported TNCuPc assemblies was measured by cyclic voltammetry (CV) and rotating disk electrode (RDE) techniques in an oxygen-saturated 0.1 M KOH. The results showed that the catalytic activity of TNCuPc/AF-MWCNTs towards oxygen reduction was a two-step, two-electron process for oxygen reduction.


2020 ◽  
Vol 16 (4) ◽  
pp. 381-392
Author(s):  
Ayman A. Gouda ◽  
Ali H. Amin ◽  
Ibrahim S. Ali ◽  
Zakia Al Malah

Background: Cadmium (Cd2+) and lead (Pb2+) have acute and chronic effects on humans and other living organisms. In the present work, new, green and accurate dispersive micro solid-phase extraction (DμSPE) method for the separation and preconcentration of trace amounts of cadmium (Cd2+) and lead (Pb2+) ions in various food, water and tobacco samples collected from Saudi Arabia prior to its Flame Atomic Absorption Spectrometric (FAAS) determinations was developed. Methods: The proposed method was based on a combination of oxidized multiwalled carbon nanotubes (O-MWCNTs) with a new chelating agent 5-benzyl-4-[4-methoxybenzylideneamino)-4H- 1,2,4-triazole-3-thiol (BMBATT) to enrich and separate trace levels of Cd2+ and Pb2+. The effect of separation parameters was investigated. The validation of the proposed preconcentration procedure was performed using certified reference materials. Results: Analyte recovery values ranged from 95-102%, indicating that the method is highly accurate. Furthermore, precision was demonstrated by the relative standard deviation (RSD < 3.0%). The limits of detection were 0.08 and 0.1 μg L−1 for Cd2+ and Pb2+ ions, respectively. The preconcentration factor was 200. Conclusion: The proposed method was used for the estimation of Cd2+ and Pb2+ ion content in various real samples, and satisfactory results were obtained. The proposed method has high adsorption capacity, rapid adsorption equilibrium, extremely low LODs, high preconcentration factors and shortens the time of sample preparation in comparison to classical SPE.


2021 ◽  
Author(s):  
Apostolos Koutsioukis ◽  
Vassiliki Belessi ◽  
Vasilios Georgakilas

A green approach for the functionalization of multiwalled carbon nanotubes (MWNTs) with hydrophilic groups and their use for the development of an ecofriendly conductive ink is described here. A known...


2010 ◽  
Vol 96 (2) ◽  
pp. 348-351 ◽  
Author(s):  
Hideyuki Katsumata ◽  
Hiroshi Kojima ◽  
Satoshi Kaneco ◽  
Tohru Suzuki ◽  
Kiyohisa Ohta

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