Oxygen Defects and Photocatalytic Activity of Bi2O3/TiO2 Nanotube-Based Catalysts
4 affiliations
- 1Escuela Superior de Ingeniería Química e Industrias Extractivas, Instituto Politécnico Nacional, Col. Zacatenco, Ciudad de México 07738, Mexico
- 2TecNM-Tecnológico de Estudios Superiores de Coacalco, 16 de Septiembre 54, Col. Cabecera municipal, Coacalco de Berriozabal, Estado de México 55700, Mexico
- 3Escuela Superior de Ingeniería Mecánica y Eléctrica (ESIME-Zacatenco), Instituto Politécnico Nacional, Col. Zacatenco, Ciudad de México 07738, Mexico
- 4Centro de Nanociencias y Micro y Nanotecnologías, Instituto Politécnico Nacional, Av. Luis Enrique Erro S/N, Ciudad de México 07708, Mexico
Abstract
The development of efficient photocatalysts for the degradation of persistent organic pollutants in wastewater remains an important challenge. In this work, Bi2O3/TiO2 heterostructured catalysts with nanotubular morphology were successfully synthesized through a hydrothermal method followed by wet impregnation, and their photocatalytic activity was evaluated for methyl orange (MO) degradation under UV irradiation. Structural, morphological, surface feature, and optical properties were systematically investigated by XRD, Raman, FTIR, XPS, SEM, HRTEM-EDS, N2 physisorption, and UV–Vis DRS analyses. Rietveld refinement confirmed the existence of oxygen defects in bismuth oxides and their concentration increased with bismuth content. The incorporation of defective Bi2O3 with TiO2 nanotubes induced bandgap narrowing and interfacial electronic interactions. Among the synthesized Bi2O3/TiO2 materials, BTI500-20 exhibited the highest photocatalytic activity, achieving complete MO removal with the highest apparent kinetic constant. Reactive species trapping experiments indicated that photogenerated holes and hydroxyl radicals were the main oxidative species involved in the degradation process. High-performance liquid chromatography (HPLC) analysis revealed the progressive degradation pathway of MO through azo bond cleavage, formation of aromatic intermediates, and subsequent generation of low-molecular-weight oxidation products. The enhanced photocatalytic performance was attributed to the defective structure and synergistic effect of the Bi2O3/TiO2 heterojunction, which promoted interfacial charge separation and facilitated the generation of reactive oxidative species.
Related
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BibTeX
@article{hernandez2026oxygen,
title = {{Oxygen Defects and Photocatalytic Activity of Bi2O3/TiO2 Nanotube-Based Catalysts}},
author = {Erika Juárez Hernández and Sergio Odin Flores and Lifang Chen and José Salmones and Julio González and Oscar A. González Vargas and Raul Borja-Urby and Jin An Wang},
journal = {Inorganics},
year = {2026},
month = oct,
doi = {10.3390/inorganics14110280},
url = {https://www.mdpi.com/2304-6740/14/11/280},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Oxygen Defects and Photocatalytic Activity of Bi2O3/TiO2 Nanotube-Based Catalysts
AU - Erika Juárez Hernández
AU - Sergio Odin Flores
AU - Lifang Chen
AU - José Salmones
AU - Julio González
AU - Oscar A. González Vargas
AU - Raul Borja-Urby
AU - Jin An Wang
PY - 2026
DA - 2026/10/30
JO - Inorganics
DO - 10.3390/inorganics14110280
UR - https://www.mdpi.com/2304-6740/14/11/280
AB - The development of efficient photocatalysts for the degradation of persistent organic pollutants in wastewater remains an important challenge. In this work, Bi2O3/TiO2 heterostructured catalysts with nanotubular morphology were successfully synthesized through a hydrothermal method followed by wet impregnation, and their photocatalytic activity was evaluated for methyl orange (MO) degradation under UV irradiation. Structural, morphological, surface feature, and optical properties were systematically investigated by XRD, Raman, FTIR, XPS, SEM, HRTEM-EDS, N2 physisorption, and UV–Vis DRS analyses. Rietveld refinement confirmed the existence of oxygen defects in bismuth oxides and their concentration increased with bismuth content. The incorporation of defective Bi2O3 with TiO2 nanotubes induced bandgap narrowing and interfacial electronic interactions. Among the synthesized Bi2O3/TiO2 materials, BTI500-20 exhibited the highest photocatalytic activity, achieving complete MO removal with the highest apparent kinetic constant. Reactive species trapping experiments indicated that photogenerated holes and hydroxyl radicals were the main oxidative species involved in the degradation process. High-performance liquid chromatography (HPLC) analysis revealed the progressive degradation pathway of MO through azo bond cleavage, formation of aromatic intermediates, and subsequent generation of low-molecular-weight oxidation products. The enhanced photocatalytic performance was attributed to the defective structure and synergistic effect of the Bi2O3/TiO2 heterojunction, which promoted interfacial charge separation and facilitated the generation of reactive oxidative species.
SN - 2304-6740
ER -