Computational Search and Stability Analysis of Two-Dimensional Tin Oxides

Material science faces a significant problem in the search for new two-dimensional materials for electrical, gas sensing, and catalytic applications. The search for novel two-dimensional tin oxide materials was carried out in this study using an evolutionary structure prediction algorithm and ab initio approaches. The results of evolutionary search calculations reveal stable Sn2O3, SnO2, SnO, and Sn3O4 and metastable Sn3O5 structures. Here, Sn2O3 is a novel structure with a tetragonal symmetry that has been confirmed to be dynamically stable by phonon and ab initio molecular dynamics simulations. Electronic structure investigations show that Sn2O3 is a perspective material for gas sensing and catalyzing applications due to the unconnected bond on the top and bottom Sn atoms. The predicted tetragonal structure of SnO2 is consistent with that in the literature. In the case of SnO, the thermodynamic phase diagram and phonon calculations showed that the two-dimensional orthorhombic structure is more stable than the tetragonal one. Ab initio molecular dynamic simulations at 300, 700, and 1100 K were performed to investigate the stability of all structures.