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.