Experimental Investigation of the Oxidation of Tin Nanoparticles

Oxidation of tin nanoparticles is studied in this paper using a simultaneous TGA/DSC technique under both constant rates of heating and isothermal modes. A two-stage oxidation process is identified. XRD study shows that the only oxide product is SnO at a temperature below 400 degrees C, and SnO and SnO2 coexist at the temperature range between 400 and 900 degrees C. On the basis of the identified oxide constituent, the first-stage oxidation of tin nanoparticles is investigated by the model-free Kinssinger method. The activation energy is found to be dependent on the conversion ratio in a broad range of 0.32-1.33 eV, and the oxidation kinetics is identified to be the classical nucleation mechanism that can be modeled by the Avrami-Erofeev equation. The melting of tin and large pressure built up in a rigid oxide shell are believed to be responsible for the heterogeneous nucleation mechanism.