Used as a catalyst in oxidation reactions, particularly in the production of terephthalic acid from p-xylene. Acts as a drying agent in paints, varnishes, and inks by accelerating the absorption of oxygen from air, promoting faster film formation. Employed in the synthesis of other cobalt-based compounds and in electroplating baths to improve adhesion and finish. Also utilized in textile dyeing as a mordant to fix dyes on fabrics. Provides blue or green coloration in glass, ceramics, enamels, and coatings, offering heat-resistant hues. In industrial settings, it serves as a precursor for cobalt oxide materials used in batteries and ceramics.