Template-free hydrothermal derived cobalt oxide nanopowders: Synthesis, characterization, and removal of organic dyes

Journal Article · Sat Sep 15 00:00:00 EDT 2012 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2012.04.070· OSTI ID:22215755

Nassar, Mostafa Y. ^[1]

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1. Chemistry Department, Faculty of Science, Benha University, Benha 13518 (Egypt)

Graphical abstract: XRD patterns of the products obtained by hydrothermal treatment at 160 °C for 24 h, and at different [Co{sup 2+}]/[CO{sub 3}{sup 2−}] ratios: (a) 1:6, (b) 1:3, (c) 1:1.5, (d) 1:1, (e) 1:0.5. Highlights: ► Spinel cobalt oxide nanoparticles with different morphologies were prepared by hydrothermal approach. ► The optical characteristics of the as-prepared cobalt oxide revealed the presence of two band gaps. ► Adsorption of methylene blue dye on Co{sub 3}O{sub 4} was investigated and the percent uptake was found to be >99% in 24 h. -- Abstract: Pure spinel cobalt oxide nanoparticles were prepared through hydrothermal approach using different counter ions. First, the pure and uniform cobalt carbonate (with particle size of 21.8–29.8 nm) were prepared in high yield (94%) in an autoclave in absence unfriendly organic surfactants or solvents by adjusting different experimental parameters such as: pH, reaction time, temperature, counter ions, and (Co{sup 2+}:CO{sub 3}{sup 2−}) molar ratios. Thence, the spinel Co{sub 3}O{sub 4} (with mean particle size of 30.5–47.35 nm) was produced by thermal decomposition of cobalt carbonate in air at 500 °C for 3 h. The products were characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), transmission electron microscope (TEM), scanning electron microscope (SEM), and thermal analysis (TA). Also, the optical characteristics of the as-prepared Co{sub 3}O{sub 4} nanoparticles revealed the presence of two band gaps (1.45–1.47, and 1.83–1.93 eV). Additionally, adsorption of methylene blue dye on Co{sub 3}O{sub 4} nanoparticles was investigated and the uptake% was found to be >99% in 24 h.

• OSTI ID: 22215755
• Journal Information: Materials Research Bulletin, Vol. 47, Issue 9; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
77 NANOSCIENCE AND NANOTECHNOLOGY
ADSORPTION
COBALT CARBONATES
COBALT IONS
COBALT OXIDES
FOURIER TRANSFORMATION
INFRARED SPECTRA
NANOSTRUCTURES
OPTICAL PROPERTIES
PARTICLE SIZE
POWDERS
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SPINELS
THERMAL GRAVIMETRIC ANALYSIS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION