Study of the surface chemistry and morphology of single walled carbon nanotube-magnetite composites

Journal Article · Tue Mar 15 04:00:00 EDT 2011 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2011.01.017· OSTI ID:21494217

Marquez-Linares, F ^[1]; Uwakweh, O N.C. ^[2]; Lopez, N ^[3]; Chavez, E ^[4]; Polanco, R ^[1]; Morant, C; Sanz, J M; Elizalde, E ^[5]; Neira, C; Nieto, S ^[1]; Roque-Malherbe, R ^[1]

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1. Institute for Physical Chemical Applied Research, School of Science, University of Turabo, PO Box 3030, Gurabo, PR 00778-3030 (Puerto Rico)
2. Engineering Science and Materials Department, College of Engineering, University of Puerto Rico-Mayagueez Campus, Mayaguez, PR 00681-9044 (Puerto Rico)
3. Chemical Engineering Department, College of Engineering, University of Puerto Rico-Mayagueez Campus, Mayaguez, PR 00681-9000 (Puerto Rico)
4. Physics Department, University of Puerto Rico-Mayagueez Campus, Mayaguez, PR 00681-9000 (Puerto Rico)
5. Department of Applied Physics, C-XII, Universidad Autonoma de Madrid, Cantoblanco, 28049-Madrid (Spain)

The study of the morphologies of the single walled carbon nanotube (SWCNT), magnetite nanoparticles (MNP), and the composite based on them was carried with combined X-ray diffraction (XRD), Raman spectroscopy (RS), scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). These techniques together with thermogravimetric analyses (TGA) and diffuse reflectance infrared transform spectroscopy (DRIFTS) confirmed the production of pure single phases, and that the composite material consisted of MNP attached to the outer surface of the SWCNT. The Moessbauer spectroscopy (MS) research showed the presence of a large quantity of Lewis acid sites in the highly dispersed magnetite particles supported on the SWCNT outer surface. The DRIFTS carbon dioxide adsorption study of the composites revealed significant adsorption of carbon dioxide, fundamentally in the Lewis acid sites. Then, the Lewis acid sites were observed to be catalytically active. Further, the electron exchange between the Lewis acid sites and the basic or amphoteric adsorbed molecules could influence the magnetic properties of the magnetite. Consequently, together with this first ever use of MS in the study of Lewis acid sites, this investigation revealed the potential of the composites for catalytic and sensors applications. -- Graphical abstract: A large amount of Lewis acid sites were found in the highly dispersed magnetite which is supported on the SWCNT outer surface. Display Omitted Research highlights: {yields} The obtained materials were completely characterized with XRD, Raman and SEM-TEM. {yields} DRIFT, TGA and adsorption of the composites allowed understand the material formation. {yields} This is the first report of a study of Lewis sites by Moessbauer spectroscopy.

• OSTI ID: 21494217
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 3 Vol. 184; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ADSORPTION
CARBON
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
COHERENT SCATTERING
COMPOSITE MATERIALS
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
GRAVIMETRIC ANALYSIS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
INORGANIC COMPOUNDS
IRON ORES
LASER SPECTROSCOPY
LEWIS ACIDS
MAGNETIC PROPERTIES
MAGNETITE
MATERIALS
MICROSCOPY
MINERALS
MOESSBAUER EFFECT
MORPHOLOGY
NANOSTRUCTURES
NANOTUBES
NONMETALS
ORES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
QUANTITATIVE CHEMICAL ANALYSIS
RAMAN SPECTROSCOPY
SCANNING ELECTRON MICROSCOPY
SCATTERING
SORPTION
SPECTROSCOPY
SURFACES
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION