Thermal stability and decomposition kinetics of AgO submicron particles prepared by potassium persulfate oxidation

Abstract

In this study, AgO submicron particles for antimicrobial application were prepared by potassium persulfate oxidation. The characterization of AgO particles was performed by XRD, XPS, SEM, TEM and TGA analysis. Its decomposition kinetics was studied by Doyle mechanism equation, Coats-Redfern equation and Ozawa approximate integration. The results showed that the as-prepared powders were composed of monoclinic AgO and small amounts of carbonate. The average width of AgO particles was about 200 nm with a rod-like morphology. AgO submicron particles could be decomposed to be Ag2O at 123 °C. When the temperature was increased to 405 °C, Ag2O was further transformed to be Ag. The decomposition reaction of AgO was controlled by Avrami-Erofeev random nucleation and subsequently growth mechanism (A1) with the apparent activation energy of 88.34 kJ/mol and the reaction frequency factor of 4.88 × 109 s-1.