Wet Synthesis of Monodisperse Cobalt Oxide Nanoparticles

Ultrafine and monodispersable colloidal cobalt oxide nanoparticles were successfully synthesized quantitatively via soft chemical approach with controlled particle size and microstructural properties for their use in technological applications. The particle size, shape, and other microstructural properties are directly influenced by their reaction conditions. The FT-IR studies give information for phase purity, and ultraviolet absorption spectroscopy helps to study the optical properties. Thermal analysis gives the information about thermal stability. With the help of X-ray diffraction pattern, the size of the particle was calculated. An electron microscope studies help in morphological characterization, and Brunauer-Emmett-Teller method gives information about surface area. Cobalt oxide nanoparticle tends to orient itself with its narrow size distribution having a crystal size around 50？nm. 1. Introduction In recent years, synthesis of transition metal oxide nanoparticles has attracted much attention because of their outstanding multifunctional physical-chemical properties for their use in different fields. The actual challenge that depends on how to optimize a cost-effective synthetic methodology via soft chemical approach that gives technological grade nanomaterials with a specific structural-morphological functional properties remains a challenge to synthetic chemists. Cobalt oxide nanopowder is widely used in many fields such as magnetic [1], gas sensor [2], lithium ion batteries [3], catalysis [4], and electrochemical [5] depending on the size, structure, shape, and phase homogeneity and with surface morphologies. Many approaches were made for the successful synthesis of cobalt oxide nanoparticles in past one decade by using different synthetic approaches, such as thermal method [6], precipitation methods [7], pyrolysis process [8], and sonochemical method [9]. However, all these methods have a limited control in particle functional properties with low yield. Therefore, it is necessary to find alternative method for the synthesis of nanopowder that should be cost-effective and environmental friendly. The soft chemical approach is the best synthetic method which helps to synthesize of cobalt oxide nanopowder. Soft chemistry that helps to increase a functional efficiency for its use in technology also helps in better understanding the crystal growth with a required shape, size, and phase purity by controlling surface energies. We have used wet chemical approach to prepare ultrapure monodisperse tetrapod-shaped cobalt oxide nanoparticles with a