Preparation of nanosized cobalt aluminate powders by a hydrothermal method

Nanosized cobalt aluminate (CoAl2O4) spinel powders have been prepared by a hydrothermal method. Titration of Co–Al mixed solution by NaOH solution yields a precursor with crystalline Co–Al-layered double hydroxide (LDH) and bayerite aluminum hydroxide (β-Al(OH)3) phases. After the precursor is hydrothermally reacted at 245 °C for 20 h, CoAl2O4 powders with a size of 65–75 nm and with a surface area of about 32.3 m2/g are prepared. The formation process has been investigated by X-ray diffraction (XRD), FT-IR, BET surface area measurement, and transmission electron microscopy (TEM) techniques.