Electronic Structures of Antimony Oxides

Abstract

This study details density functional theory calculations on all the polymorphs of the binary oxides of antimony (Sb 2 O 3 , Sb 2 O 4 , and Sb 2 O 5 ) to assess the electronic structures and differences in bonding between Sb III and Sb V ions with oxygen. The results show that lone-pair formation is via a similar mechanism to other main group elements which exhibit an oxidation state of two less than the group valence, through direct interaction of Sb 5s and O 2p states, with the antibonding interaction stabilized by Sb 5p states. Furthermore, structural distortion of the Sb site directly affects the strength of the resulting lone pair. In addition to the analysis of the density of states and charge density, band structures and optical absorption spectra are also detailed. The results indicate that all materials are indirect band gap materials, with the exception of the β-polymorphs of Sb 2 O 3 and Sb 2 O 4 . In addition, the fundamental and optical band gaps of the materials are found to decrease from Sb 2 O 3 to Sb 2 O 4 to Sb 2 O 5 . Calculated band-edge effective masses suggest that β-Sb 2 O 3 may exhibit reasonable p-type properties. Furthermore, β-Sb 2 O 3 , γ-Sb 2 O 3 , and Sb 2 O 5 possess low electron effective masses which are conducive with strong n-type conduction.

The electronic structure of the antimony chalcogenide series: Prospects for optoelectronic applications

“…The size of the fundamental and optical band gaps are therefore, dependent on the Sb s -Ch p anti-bonding interaction and the degree of mixing of states at the VBM, which effects the photo-physical properties of these and other similar lone pair materials. Sb 2 O 3 has a calculated fundamental and optical band gap greater than 3.1 eV making it a potential transparent conducting oxide with hole and electronic effective masses of 2.57 and 0.85, respectively [114]. The fundamental band gap of the antimony sulphide (1.29 eV), and selenide (0.75 eV) are indirect in nature, albeit underestimated by PBE, with their smallest direct gap being 1.36 eV and 0.78 eV, respectively.…”

Investigations on the Antimony Promotional Effect on CeO2–WO3/TiO2 for Selective Catalytic Reduction of NOx with NH3

“…ÞÞ Antimony oxide is known to form three binary oxides, which have been widely used as dopants to enhance the material conductivity and elevate catalyst activity. [29][30][31] It has been demonstrated that antimony-doped catalysts are active and selective for several partial oxidation processes. [32] For example, doping SnO 2 oxide with Sb 3 + decreased the conductivity, whereas doping with SbV enhanced the n-type conductivity.…”

Parallel responses of human epidermal keratinocytes to inorganic SbIII and AsIII

“…However, crystals of AsV and SbV oxides pack quite differently due to the slightly larger size of the latter. This distinction in size and geometry,[7, 8] which can affect interactions with macromolecules,[9] may help rationalize that SbV has little obvious biological activity in human keratinocytes, indicating the rate of reduction to SbIII in them is too low to produce effects, despite the facile AsV reduction to AsIII in this cell type. [10]…”