CoFe2O4 nanoparticles as a catalyst: synthesis of a forest of vertically aligned CNTs of uniform diameters by plasma-enhanced CVD

AbstractA carbon nanotube triode using Helicon Plasma-enhanced CVD with electroplated NiCo catalyst has been successfully fabricated. Isolated NiCo based metal catalyst was deposited at the bottom of the cathode wells by electroplating methods to control the density of carbon nanotubes and also reduce the activation energy of its growth. Helicon Plasma-enhanced CVD (HPECVD) has been used to deposit nanotubes at 400°C. Vertically aligned carbon nanotubes were then grown selectively on the electroplated Ni catalyst. Field emission measurements were performed with a triode structure. At a cathode to anode gap of 1.1mm, the turn on voltage for the gate was 170V.

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Fabrication of vertically-aligned CNT electrodes using plasma-enhanced CVD for chemical sensors.

10.7567/ssdm.2007.h-3-3 ◽

2007 ◽

Author(s):

Yoshihiro Kojima ◽

Shigeru Kishimoto ◽

Mina Okochi ◽

Hiroyuki Honda ◽

Takashi Mizutani

Keyword(s):

Chemical Sensors ◽

Plasma Enhanced Cvd ◽

Vertically Aligned

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A Dual-RF-Plasma Approach for Controlling the Graphitic Order and Diameters of Vertically-Aligned Multiwall Carbon Nanotubes

MRS Proceedings ◽

10.1557/proc-858-hh3.11 ◽

2004 ◽

Vol 858 ◽

Author(s):

Jitendra Menda ◽

Lakshman Kumar Vanga ◽

Benjamin Ulmen ◽

Yoke Khin Yap ◽

Zhengwei Pan ◽

...

Keyword(s):

Carbon Nanotubes ◽

Arc Discharge ◽

Multiwall Carbon Nanotubes ◽

Chemical Vapor ◽

Rf Plasma ◽

Temperature Growth ◽

Plasma Enhanced Cvd ◽

Vertically Aligned ◽

Multiwall Carbon ◽

Unique Capability

ABSTRACTPlasma enhanced chemical vapor deposition (PECVD) is a unique technique for growing vertically-aligned multiwall carbon nanotubes (VA-MWNTs) at controllable tube densities. This technique is of considerable importance for low temperature growth of VA-MWNTs at desired locations. However, the graphitic order of these MWNTs is inferior to those grown by laser ablation, arc discharge, and thermal CVD techniques. Previously, these VA-MWNTs were grown by a one-plasma approach (DC, microwave etc), either for gas decomposition or substrate biasing. Here, we describe a dual-RF plasma enhanced CVD (dual-RF-PECVD) technique that offers unique capability for controlling the graphitic order and diameters of VA-MWNTs.

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Experimental and Theoretical Comparable Study of Pure and Zinc Porphyrin Surface Modified ZnO Nanorod Arrays for Hybrid Solar Cell Applications

10.32792/utq/utjsci/vol7/2/26 ◽

2020 ◽

pp. 114-119

Keyword(s):

Solar Cell ◽

Electrochemical Impedance ◽

Hybrid Solar Cell ◽

Cell Performance ◽

Solar Cell Performance ◽

Solar Cell Efficiency ◽

Cell Efficiency ◽

Annealing Effects ◽

Vertically Aligned ◽

Surface Modified

Experimental and theoretical study Porphyrin-grafted ZnO nanowire arrays were investigated for organic/inorganic hybrid solar cell applications. Two types of porphyrin – Tetra (4-carboxyphenyle) TCPP and meso-Tetraphenylporphine (Zinc-TPP)were used to modify the nanowire surfaces. The vertically aligned nanowires with porphyrin modifications were embedded in graphene-enriched poly (3-hexylthiophene) [G-P3HT] for p-n junction nanowire solar cells. Surface grafting of ZnO nanowires was found to improve the solar cell efficiency. There are different effect for the two types of porphyrin as results of Zn existing. Annealing effects on the solar cell performance were investigated by heating the devices up to 225 °C in air. It was found that the cell performance was significantly degraded after annealing. The degradation was attributed to the polymer structural change at high temperature as evidenced by electrochemical impedance spectroscopy measurements.

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Magnetic Properties of Fe3O4/CoFe2O4 Composite Nanoparticles with Core/Shell Architecture

Ukrainian Journal of Physics ◽

10.15407/ujpe65.10.904 ◽

2020 ◽

Vol 65 (10) ◽

pp. 904

Author(s):

V. O. Zamorskyi ◽

Ya. M. Lytvynenko ◽

A. M. Pogorily ◽

A. I. Tovstolytkin ◽

S. O. Solopan ◽

...

Keyword(s):

Magnetic Properties ◽

Spinel Ferrite ◽

Composite Nanoparticles ◽

Core Shell ◽

Cofe2o4 Nanoparticles ◽

Core Diameter ◽

The Core ◽

Shell Particles ◽

Interface Parameters ◽

Shell Composite

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.

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