Electronic, Electrical, and Magnetic Behavioral Change of SiO₂-NP-Decorated MWCNTs

Abstract

Silicon-oxide-nanoparticle (SiO2-NP) heteroatoms were decorated/deposited onto multiwall carbon nanotube (MWCNT) surface to tune the properties of MWCNTs for electronic and magnetic applications. To achieve this objective, SiO2-NPs and MWCNTs were prepared and suspended together into toluene and heated at <100 °C for the formation of MWCNTs/SiO2-NP nanocomposites. A change in the microstructure, electronic, electrical, and magnetic behaviors of MWCNT nanocomposites decorated/deposited with silicon content was investigated using different techniques, viz., scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy for structural, compositional, and electronic structure, while current–voltage was used for electrical properties and field-dependent magnetization and electron spin resonance techniques were used for magnetic properties. The results indicated that SiO2-NPs adhered onto MWCNTs, resulting in variation in the material conductivity with the Si-NP content. The coercivity of MWCNT nanocomposites adhered with 1.5 atom % Si-NPs (HC@40 K = 689 Oe) is higher than that of those adhered with 5.75 atom % Si-NPs (HC@40 K = 357 Oe). In general, the results provide information about the possibilities of tuning the electronic, electrical, and magnetic properties of MWCNTs by adherence of SiO2-NPs onto them. This tuning of material properties could be useful for different electronic and magnetic device applications.

Improvement of Laccase Activity Via Covalent Immobilization over Mesoporous Silica Coated Magnetic Multiwalled Carbon Nanotubes for the Discoloration of Synthetic Dyes

“…The process of coating mesoporous silica on the as-synthesized magnetic multiwalled carbon nanotubes (Fe 3 O 4 -MWCNT) was performed via a solution-phase approach using cetyltrimethyl ammonium bromide (CTAB) as a surfactant. , Briefly, 0.5 g of magnetic multiwalled carbon nanotubes (Fe 3 O 4 -MWCNTs), 1 g of CTAB, 40 mL of ethanol, 1 mL of ammonium hydroxide (NH 4 NO 3 ), and deionized water (1 mL) were added in series into a three-necked flask followed by ultrasonic distribution for 0.5 h to form a homogeneous mixture. With vigorous stirring, 2 mL of tetraethylorthosilicate (TEOS) was added slowly into the Fe 3 O 4 -MWCNTs solution and maintained at 40 °C for 12 h with a stirring speed of 300 rpm.…”

Coexistence of ferromagnetism and superconductivity in MWCNT/Bi2SiO5 nanocomposites

“…Hence, magnetic NP-filled CNTs are ideal as reinforcing materials for the fabrication of magnetic nanocomposite materials. Various synthesis methods such as sol-gel, ultrasonication, sputtering, high energy ball milled, and ion exchange has been used to embed magnetic NPs in a non-magnetic matrix [21][22][23][24][25].…”