Investigation of thermodynamic properties of Co2O3 powder

The isobaric molar heat capacities of powder of Co2O3 were determined by an adiabatic calorimeter in the temperature range from 78 to 350 K. No phase transition takes place in this temperature range. The relationship of Cp,m with thermodynamic temperature T was established as Cp,m=−5×10−6T3+0.0026T2+0.0325T+4.2592 (J K−1 mol−1), fitting coefficient R2=0.9996. According to this relationship and the relationships between thermodynamic functions, the thermodynamic functions of powder of Co2O3 were derived with 298.15 K as reference temperature. Thermal decomposition of Co2O3 powder was studied through thermogravimetry (TG). The possible mechanism of the thermal decomposition reaction was suggested according to the TG result.