Doping‐induced diffused phase transition triggers gas‐sensing performance of Sn‐doped BaTiO₃ nanostructures

Abstract

The formation of polar nanoregions with a smaller doping concentration of Sn into BaTiO3 nanostructures governs significantly better gas‐sensing response for a NO2 gas at room temperature. Appropriate Sn doping in BaTiO3 nanostructures not only modifies the electronic structure but is also responsible for diffused phase transition in its crystal structure. Here, in this study, we performed high‐resolution transmission electron microscopy of the Sn‐doped BaTiO3 samples to observe the formed polar nanoregions; 0.2 M% Sn‐doped BaTiO3 possesses a higher polarization value at room temperature to adsorb NO2 gas on the surface of the thick film resistor‐based gas sensor, improving its gas‐sensing performance. The electronic structure and density of states of pristine and Sn‐doped BaTiO3 were studied by density functional theory calculations, and the results of the same revealed improved gas‐sensing performance in the case of Sn‐doped BaTiO3 nanostructures.

New BaTi0.96Cu0.02X0.02O3 (X = V, Nb) Photocatalysts for Dyes Effluent Remediation: Broad Visible Light Response

“…Owing to the insertion of Cu 2+ , V 4+ and Nb 5+ ions, the conduction band (CB) is possibly derived from Cu-3d, V-3d or Nb-4d and Ti-3d electrons, while the valence band (VB) mostly arises from Cu-3d, V-3d or Nb-4d plus O-2p and Ti-3d states. As a result, the intense reductions of the band gap energy of BaTi 0.96 Cu 0.04 O 3 , BaTi 0.96 Cu 0.02 V 0.02 O 3 and BaTi 0.96 Cu 0.02 Nb 0.02 O 3 catalysts can be assigned to the presence of impurity states below the conduction band (CB) and above the valence band (VB) due to Cu 2+ , V 4+ and Nb 5+ ions and the formation of oxygen vacancies for charge neutrality [18,30,31]. The sunlight spectrum has nearly 52% infrared red radiation (700-2500 nm), 43% visible light rays (400-700 nm) and 5% ultraviolet wavelengths (280-400 nm) [32].…”