Effects of fluorination and thermal shock on the photocatalytic activity of Bi2O3 nanopowders

2021-10-05
Bouzıanı, Asmae
Park, Jongee
Öztürk, Abdullah
© 2021 Elsevier B.V.Fluorinated Bi2O3 (F-Bi2O3) nanopowder was prepared via fluorination followed by thermal shock of α-Bi2O3 nanopowder. The XRD, FTIR, SEM, and DRS characterization techniques were employed to investigate the effects of fluorine (F) insertion into the α-Bi2O3 host and the thermal shock from different temperatures. The crystal structure, optical and photocatalytic properties of the F-Bi2O3 nanopowders prepared were researched. The XRD results confirmed the substitution of O2- with F-. The FTIR results revealed that the coordination of Bi atoms changed upon F- substitution. The incorporation of F into the α-Bi2O3 host and thermal shock did not influence the morphology but modified the band structure of α-Bi2O3, leading to a red-shift in the optical absorption edge. Also, the bandgap narrowed from 2.8 eV to 2.6 eV. The density functional theory calculation proved that the F 2p orbitals were positioned in the valence band (VB), resulting in broader and more spread bands for F-Bi2O3. The results suggested that the photoexcited charge carrier mobility in the valence band (VB) and conduction band (CB) are enhanced upon F insertion into α-Bi2O3. The photocatalytic efficiency of the synthesized nanopowders was assessed by the degradation of Bromocresol Green (BG) under visible light illumination. Photocatalytic activity improved upon fluorination. The F-Bi2O3 nanopowders thermally shocked from higher temperatures showed negligible photocatalytic performance. The best photocatalytic performance of 70% BG degradation was realized after 180 min visible irradiation for the F-Bi2O3 nanopowder thermal shocked from 500 °C.
Citation Formats
A. Bouzıanı, J. Park, and A. Öztürk, “Effects of fluorination and thermal shock on the photocatalytic activity of Bi2O3 nanopowders,” pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85108664403&origin=inward.