Optimal synthetic route for obtaining Co/In layered double hydroxide

Abstract

Cobalt-indium layered double hydroxides were successfully synthesized via coprecipitation and mechanochemical synthesis with subsequent soft hydrothermal treatment and additional crystallization. The latter method was shown to have advantages over coprecipitation and therefore the mechanochemical route was considered to be optimal for obtaining well-crystallized LDH samples, which do not contain extraneous crystalline phases within the detection limit of X-ray diffraction. The samples were characterized by FTIR spectroscopy, Raman spectroscopy, and transmission electron microscopy. The peroxidase-like activity of the samples was estimated, and the crystal lattice parameters were calculated. The possibility of obtaining cobalt-indium layered double hydroxides with a cationic ratio of Co2+: In3+ = 2 : 1 and 1.5 : 1 was shown. Increasing the aging temperature presumably led to the partial oxidation of cobalt in the samples into trivalent state resulted in the peroxidase-like activity of the samples.