Physical and electrochemical study of cobalt oxide nano- and microparticles

• Published in: Materials characterization 2014-07, Vol.93, p.191-197
• Main Authors: Alburquenque, D., Vargas, E., Denardin, J.C., Escrig, J., Marco, J.F., Ortiz, J., Gautier, J.L.
• Format: Article
• Language: English
• Subjects: CERAMICS; Co3O4; COBALT OXIDES; COERCIVE FORCE; Cross-disciplinary physics: materials science; rheology; Cyclic voltammetry; ELECTRODES; Exact sciences and technology; FOURIER TRANSFORM SPECTROMETERS; FOURIER TRANSFORMATION; INFRARED SPECTRA; MATERIALS SCIENCE; Nanocrystals; NANOPARTICLES; NANOSCIENCE AND NANOTECHNOLOGY; NANOSTRUCTURES; PARAMAGNETISM; PARTICLE SIZE; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; POWDERS; SCANNING ELECTRON MICROSCOPY; Solidification; Spinel; SPINELS; SURFACE AREA; TRANSMISSION ELECTRON MICROSCOPY; VIBRATING SAMPLE MAGNETOMETERS; VOLTAMETRY; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY; XPS
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2014.02.015

Cobalt oxide nanocrystals of size 17–21nm were synthesized by a simple reaction between cobalt acetate (II) and dodecylamine. On the other hand, micrometric Co3O4 was prepared using the ceramic method. The structural examination of these materials was performed using powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM and HRTEM). XRD studies showed that the oxides were pure, well-crystallized, spinel cubic phases with a-cell parameter of 0.8049nm and 0.8069nm for the nano and micro-oxide, respectively. The average particle size was 19nm (nano-oxide) and 1250μm (micro-oxide). Morphological studies carried out by SEM and TEM analyses have shown the presence of octahedral particles in both cases. Bulk and surface properties investigated by X-ray photoelectron spectroscopy (XPS), point zero charge (pzc), FTIR and cyclic voltammetry indicated that there were no significant differences in the composition on both materials. The magnetic behavior of the samples was determined using a vibrating sample magnetometer. The compounds showed paramagnetic character and no coercivity and remanence in all cases. Galvanostatic measurements of electrodes formed with nanocrystals showed better performance than those built with micrometric particles. •Spinel Co3O4 nanoparticles and microparticles with same structure but with different cell parameters, particle size and surface area were synthesized.•Oxide nanoparticles showed better electrochemical behavior than micrometric ones due to area effect.