DFT + U +V Investigation on Adsorption of Gas Molecules (CO, SO<sub>2</sub>, NO, and NO<sub>2</sub>) on Ni Doped Bismuth Ferrite Oxide (010)

The structural and electrical adsorption performance of carbon monoxide (CO), nitrous oxide (NO), nitrous dioxide (NO 2 ), and sulphur dioxide (SO 2 ) are explored using density functional theory calculations on Ni-doped atoms in the crystal structure of bismuth ferrite oxide (BFO). DFT+U+V offers a more complete description than either DFT or DFT+U alone. Good agreement with the experiments is obtained for both the band gap and the crystal field splitting. Ni-doped BFO (010) has adsorption energies of -0.35443 Ry for CO, -0.056076 Ry for NO, -5.64867 Ry for NO 2 , and -55.5483 Ry for SO 2 . Also, it was found that the energy of the band gap in pure BFO (010) can be lowered by adding Ni atoms. Further evidence from the DOS plot that Ni-doped BFO (010) may be considered as an emerging doped perovskite in high temperature gas sensing system for SO 2 detection.