Cobalt Oxide Nanoparticles
Cobalt has different oxide compounds such as cobalt monoxide (CoO), cobalt(II, III) oxide (Co3O4), and cobalt(III) oxide (Co2O3). Cobalt monoxide has an olive-green or red appearance while cobalt (II, III) oxide has a black appearance. The nanoparticles of these materials are usually in powder form. Cobalt oxides usually have cubic (CoO, Co3O4) or trigonal (Co2O3) crystal structure. High theoric specific capacities of CoO (715 mAh/g ) and Co3O4 (890 mAh/g)have attracted considerable attention for applications in lithium-ion batteries.Co3O4 is an important p-type semiconductor with antiferromagnetic properties. It is used in various different applications such as pigments, catalysis, sensors, electrochemistry, magnetism, solid-state sensors, and electrochromic devices. CoO has been well known as the pigment cobalt blue in pottery. CoO is also antiferromagnetic and electrically insulating. It is utilized in gas sensing applications, catalytic applications, and water-splitting processes. CoO is also used as a precursor for obtaining cobalt salts.