The role of tin species in doped iron (III) oxide for photocatalytic degradation of methyl orange dye under UV light

Nurul Affiqah Arzaee; Nadia Betti; Ahmed Al-Amiery; Wan Nor Roslam Wan Isahak

doi:10.1016/j.heliyon.2023.e18076

The role of tin species in doped iron (III) oxide for photocatalytic degradation of methyl orange dye under UV light

Heliyon. 2023 Jul 7;9(7):e18076. doi: 10.1016/j.heliyon.2023.e18076. eCollection 2023 Jul.

Authors

Nurul Affiqah Arzaee¹, Nadia Betti², Ahmed Al-Amiery¹, Wan Nor Roslam Wan Isahak¹

Affiliations

¹ Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia.
² Materials Engineering Department, University of Technology-Iraq, P.O. Box: 10001, Baghdad, Iraq.

Abstract

Iron (III) oxide, a stable semiconductor with versatile applications, was synthesized alongside Sn-doped Fe₂O₃ (Sn-Fe₂O₃) using the sol-gel technique. Characterization via X-ray diffraction, field-emission scanning electron microscopy, and UV-visible spectroscopy confirmed the presence of α- and γ-Fe2O3 phases in the synthesized powders. Incorporation of the dopant reduced the initial band gap energy of Fe₂O₃ (2.2 eV) by approximately 0.1 eV. To evaluate photocatalytic performance, Fe₂O₃ and Sn-Fe₂O₃ were tested for decolorization efficiency of a methyl orange solution. Results revealed the 5 wt% Sn-doped catalyst as optimal, achieving complete degradation of methyl orange within 120 min under simulated solar light. The addition of small amounts of Sn effectively reduced the Fe₂O₃ band gap and significantly enhanced photocatalytic performance. Investigation of pH and dye concentration impact on photocatalytic degradation revealed superior activity under acidic conditions compared to alkaline. Furthermore, maintaining a moderate concentration of methyl orange (10 ppm) ensured optimum photocatalytic activity.

Keywords: Dye degradation; Optical properties; Photocatalysis; Sn-doped nanocomposites; Sol-gel.