Evolution Mechanism of Metallic Dioxide MO2 (M = Mn, Ti)‎ from Nanorods to Bulk Crystal: First-Principles Research

Abstract EN

Using first-principle calculations, the surface energy, cohesive energy, and electronic properties of α-MnO2 and rutile TiO2 nanorods and microfacets were investigated and clarified to, in the first instance, determine the evolution mechanism.

The results show that the surface energies of α-MnO2 nanorods and microfacets conform to function 1.0401 Jm−2 + N × 0.608 Jm−2, while the surface energies of the rutile TiO2 nanorods and microfacets are governed by a 1.0102 × 1.1997 rule.

Their electronic properties, such as the Mulliken population and Mulliken charge, can only be normalized by their surface areas to attain a linear function.

Meanwhile, the surface energy of α-MnO2 with the nanostructure closely conforms to the function for normalized Mulliken population and Mulliken charge as f(x)=102.9×x+0.101 with an R2 value of 0.995.

Thus, our research into the evolution mechanism affecting the surface effect of nanometer materials will be useful for investigating the intrinsic mechanism of the nanometer effect and doping process of metallic dioxide catalysts.