Thermodynamic Modeling of Oxidation of Tin Nanoparticles

Abstract

A thorough thermodynamic analysis of oxidation of tin nanoparticles was performed. Solid tin oxides SnO2, Sn3O4 and SnO were considered according to the bulk phase diagram and a number of experimental results on tin nanostructures oxidation were taken into account in the assessment. Two equilibrium models with different spatial configuration, namely two single-component particles and core–shell model were explored. The surface energies for solid SnO and Sn3O4 were obtained on the basis of DFT calculations while the interfacial energies at SnO2(s)/Sn(l) and Sn3O4(s)/Sn(l) interfaces were assessed using a broken bond approximation. The opposite influence of nanosizing on stability of SnO2 and SnO/Sn3O4 oxides is demonstrated. It is due to the surface contribution which is higher for SnO2(s) than Sn(l) while lower for SnO(s) and Sn3O4(s) compared to Sn(l). This situation can explain some experimental findings during oxidation of Sn nanoparticles, namely an increased stability of SnO(s) and Sn3O4(s) with respect to both liquid tin and solid tin dioxide.