scholarly journals Synthesis of Fe3O4/Pt Nanoparticles Decorated Carbon Nanotubes and Their Use as Magnetically Recyclable Catalysts

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Hongkun He ◽  
Chao Gao

We report a facile approach to prepare Fe3O4/Pt nanoparticles decorated carbon nanotubes (CNTs). The superparamagnetic Fe3O4nanoparticles with average size of4∼5 nm were loaded on the surfaces of carboxyl groups functionalized CNTs via a high-temperature solution-phase hydrolysis method from the raw material of FeCl3. The synthesis process of magnetic CNTs is green and readily scalable. The loading amounts of Fe3O4nanopartilces and the magnetizations of the resulting magnetic CNTs show good tunability. The Pt nanopaticles with average size of 2.5 nm were deposited on the magnetic CNTs through a solution-based method. It is demonstrated that the Fe3O4/Pt nanoparticles decorated CNTs have high catalytic activity in the reduction reaction of 4-nitrophenol and can be readily recycled by a magnet and reused in the next reactions with high efficiencies for at least fifteen successive cycles. The novel CNTs-supported magnetically recyclable catalysts are promising in heterogeneous catalysis applications.

2019 ◽  
Vol 48 (21) ◽  
pp. 7130-7137 ◽  
Author(s):  
Kentaro Ichihashi ◽  
Satoshi Muratsugu ◽  
Shota Miyamoto ◽  
Kana Sakamoto ◽  
Nozomu Ishiguro ◽  
...  

Enhanced oxygen reduction reaction performances were achieved on size-controlled Pt nanoparticle catalysts prepared by the copolymerization of a Pt4-pyrrole complex and pyrrole monomer in the presence of multi-wall carbon nanotubes.


2020 ◽  
Vol 20 (5) ◽  
pp. 2736-2745 ◽  
Author(s):  
Haohua Kuang ◽  
Yi Cheng ◽  
Cheng Qiang Cui ◽  
San Ping Jiang

Carbon nanotubes (CNTs) are one of the most common catalysts supports for the development of electrocatalysts for O2 reduction reaction (ORR) of electrochemical devices such as polymer electrolyte membrane fuel cells (PEMFCs) and metal-air batteries due to their high electrical conductivity and high stability. In addition to the electrical conductivity and stability, the number of inner tubes or walls also influence the electrocatalytic activity of the supported catalysts. Here we study the electrocatalytic activity of Pt nanoparticles (NPs) supported on CNTs (Pt/CNTs) as a function of number of walls towards ORR in both alkaline and acid solutions. The results indicate that the mechanism of ORR on Pt/CNTs does not change with the number of walls of CNTs support but the number of walls of CNTs supports has a significant effect on the electrocatalytic activity of supported Pt NPs. Pt NPs supported on double-walled CNTs (DWCNTs) exhibit a much better activity for ORR, as compared with that supported on single-walled and multi-walled CNTs (SWCNTs and MWCNTs). The high electrocatalytic activity of DWCNTs-supported Pt NPs is contributed to the fast electron transfer between the outer wall and inner tubes of DWCNTs for ORR through electron tunnelling process under the electrochemical polarization driving force.


RSC Advances ◽  
2015 ◽  
Vol 5 (81) ◽  
pp. 66471-66475 ◽  
Author(s):  
Haijing Liu ◽  
Meiling Dou ◽  
Feng Wang ◽  
Jingjun Liu ◽  
Jing Ji ◽  
...  

PtFe@Pt nanoparticles with ordered intermetallic cores and Pt shells were supported on CNTs and developed as an ORR electrocatalyst.


2016 ◽  
Vol 3 (6) ◽  
pp. 821-827 ◽  
Author(s):  
Hongxing Jia ◽  
Zijun Sun ◽  
Daochuan Jiang ◽  
Shangfeng Yang ◽  
Pingwu Du

This study reported the first system of Fe-porphyrin conjugated network on carbon nanotubes for ORR, which exhibited excellent performance with high catalytic activity, robust stability, and good methanol tolerance.


2012 ◽  
Vol 174-177 ◽  
pp. 747-750
Author(s):  
Xing Xin Jia ◽  
Wen Yuan Gao ◽  
Mei Hong Niu

The nanosized TiO2was prepared by microemulsion process in the system of cyclohexane/[Span80 combine with Tween40]/water with TiOSO4as raw material. The synthesis process of the powder was investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and laser particle size analysis (LPSA). The results showes that TiO2with the average size of 19.5nm and narrow size distribution was prepared under these conditions of Span80 of 8g and Tween40 of 2g as the emulsifier, water/oil mass ratio of 1/4, amount of TiOSO4of 10mL with the consistency of 0.8mol/L, calcination temperature of 480 °C for 20min.


2019 ◽  
Author(s):  
Du Sun ◽  
yunfei wang ◽  
Kenneth Livi ◽  
chuhong wang ◽  
ruichun luo ◽  
...  

<div> <p>The synthesis of alloys with long range atomic scale ordering (ordered intermetallics) is an emerging field of nanochemistry. Ordered intermetallic nanoparticles are useful for a wide variety of applications such as catalysis, superconductors, and magnetic devices. However, the preparation of nanostructured ordered intermetallics is challenging in comparison to disordered alloys, hindering progress in materials development. We report a process for converting colloidally synthesized ordered intermetallic PdBi<sub>2</sub> to ordered intermetallic Pd<sub>3</sub>Bi nanoparticles under ambient conditions by an electrochemically induced phase transition. The low melting point of PdBi<sub>2</sub> corresponds to low vacancy formation energies which enables the facile removal of the Bi from the surface, while simultaneously enabling interdiffusion of the constituent atoms via a vacancy diffusion mechanism under ambient conditions. The resulting phase-converted ordered intermetallic Pd<sub>3</sub>Bi exhibits 11x and 3.5x higher mass activty and high methanol tolerance for the oxygen reduction reaction compared to Pt/C and Pd/C, respectively,which is the highest reported for a Pd-based catalyst, to the best of our knowledge. These results establish a key development in the synthesis of noble metal rich ordered intermetallic phases with high catalytic activity, and sets forth guidelines for the design of ordered intermetallic compounds under ambient conditions.</p> </div>


2020 ◽  
Vol 16 (4) ◽  
pp. 617-624 ◽  
Author(s):  
Yao Feng ◽  
Ran Wang ◽  
Juanjuan Yin ◽  
Fangke Zhan ◽  
Kaiyue Chen ◽  
...  

Background: 4-nitrophenol (4-NP) is one of the pollutants in sewage and harmful to human health and the environment. Cu is a non-noble metal with catalytic reduction effect on nitro compounds, and.has the advantages of simple preparation, abundant reserves, and low price. Carbon nanotubes (CNT) are widely used for substrate due to their excellent mechanical stability and high surface area. In this study, a simple method to prepare CNT-Cu2O by controlling different reaction time was reported. The prepared nanocomposites were used to catalyze 4-NP. Methods: CNTs and CuCl2 solution were put into a beaker, and then ascorbic acid and NaOH were added while continuously stirring. The reaction was carried out for a sufficiently long period of time at 60°C. The prepared samples were dried in a vacuum at 50°C for 48 h after washing with ethyl alcohol and deionized water. Results: Nanostructures of these composites were characterized by scanning electron microscope and transmission electron microscopy techniques, and the results at a magnification of 200 nanometers showed that Cu2O was distributed on the surface of the CNTs. In addition, X-ray diffraction was performed to further confirm the formation of Cu2O nanoparticles. The results of ultraviolet spectrophotometry showed that the catalytic effect of the compound on 4-NP was obvious. Conclusions: CNTs acted as a huge template for loading Cu2O nanoparticles, which could improve the stability and cycle performance of Cu2O. The formation of nanoparticles was greatly affected by temperature and the appropriate concentration, showing great reducibility for the 4-NP reduction reaction.


2021 ◽  
Author(s):  
Kaneyuki Taniguchi ◽  
Jhon Lehman Cuya Huaman ◽  
Dausuke Iwata ◽  
Shun Yokoyama ◽  
Takatoshi Matsumoto ◽  
...  

Alloying Pt with transition elements as electrodes in fuel cells has been proposed to solve the CO poisoning effect besides cost-benefit. Consequently, the use of Ni-Pt nanoparticles (NPs) has been...


2021 ◽  
Vol 23 (7) ◽  
pp. 4454-4454
Author(s):  
Kunran Yang ◽  
Jeremie Zaffran ◽  
Bo Yang

Correction for ‘Fast prediction of oxygen reduction reaction activity on carbon nanotubes with a localized geometric descriptor’ by Kunran Yang et al., Phys. Chem. Chem. Phys., 2020, 22, 890–895, DOI: 10.1039/C9CP04885E.


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