Unlocking the effect of Zn2+ on crystal structure, optical properties, and photocatalytic degradation of perfluoroalkyl substances (PFAS) of Bi2WO6

• Autores: Larralde, A. L.; Hojamberdiev, M.; Vargas, R.; Madriz, L.; Yubuta, K.; Sannegowda, L.; Sadok, I.; Krzyszczak-Turczyn, A.; Oleszczuki, P.; Czech, B.
• Año de publicación: 2023
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Environmental Science Water Research and Technology, 2023, 9:2866
• Materia: Agua; Purificación del agua; Química inorgánica
• Institución: Instituto Nacional de Tecnología Industrial

Bismuth tungstate (Bi2WO6) with a layered structure and visible light response exhibits excellent photocatalytic activity. To enhance its photocatalytic activity for the degradation of perfluoroalkyl substances (PFAS), Zn2+ is partially substituted for Bi3+ in the Bi2WO6 lattice in this study. Particularly, the effect of Zn2+ content (0–22.5 at%) on the crystal structure, optical property, and photocatalytic activity for the photodegradation of PFAS of Bi2WO6 is investigated. According to the Le Bail fits, the unit-cell volume is slightly reduced from 487.7 Å3 to 480.8 Å3 by the partial substitution of smaller Zn2+ (0.74 Å for CN = 6) for larger Bi3+ (1.03 Å for CN = 6) in the Bi2WO6 crystal lattice, and the solubility of Zn2+ in the Bi2WO6 lattice is found to be below 17.5 at%. The partial substitution of Zn2+ influences the self-aggregation of nanoparticles, Ostwald ripening, and self-organization of nanoplates, resulting in different morphologies. Although the optical bandgap energy of Bi2WO6 is not significantly altered upon the partial substitution of Zn2+, the conduction and valence bands simultaneously shift upward. Among the Bi2−xZnxWO6+δ photocatalysts, 2.5 at% Zn2+-substituted Bi2WO6 exhibits larger water oxidation photocurrent density (0.316 mA cm−2 at 1.23 VRHE) and the highest photocatalytic activity for the photodegradation of PFHxA (k1 = 0.012 min−1). The trapping experiments confirm that the photo-excited holes (h+) and superoxide radicals (O2˙−) are the major reactive species involved in the photodegradation of PFHxA. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS) reveals that decarboxylation and defluorination are the main possible routes for the photodegradation of PFHxA over Bi2xZnxWO6+ photocatalysts. Our findings suggest that the partial Zn2+-to-Bi2+ substitution can enhance the photocatalytic activity of Bi2WO6 for the degradation of PFAS.
Fil: Larralde, A. L. Instituto Nacional de Tecnología Industrial. Gerencia Operativa de Desarrollo Tecnológico e Innovación. Subgerencia Operativa de Energía y Movilidad (INTI-GODTeI-SOEyM); Argentina
Fil: Larralde, A. L. Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); Argentina
Fil: Hojamberdiev, M. Technische Universität Berlin. Institut für Chemie (TU); Alemania
Fil: Vargas, R. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico de Chascomús (CONICET-INTECH); Argentina
Fil: Vargas, R. Universidad Nacional de San Martín. Escuela de Bio y Nanotecnologías (UNSAM); Argentina
Fil: Madriz, L. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Tecnológico de Chascomús (CONICET-INTECH); Argentina
Fil: Madriz, L. Universidad Nacional de San Martín. Escuela de Bio y Nanotecnologías (UNSAM); Argentina
Fil: Yubuta, K. Department of Applied Quantum Physics and Nuclear Engineering; Japón
Fil: Sannegowda, L. K. Vijayanagara Sri Krishnadevaraya University. Department of Studies in Chemistry; India
Fil: Sadok, I. The John Paul II Catholic University of Lublin. Faculty of Medicine. Institute of Biological Sciences. Department of Chemistry; Polonia
Fil: Krzyszczak-Turczyn, A. The John Paul II Catholic University of Lublin. Faculty of Medicine. Institute of Biological Sciences. Department of Chemistry; Polonia
Fil: Krzyszczak-Turczyn, A. Maria Curie-Skodowska University in Lublin. Faculty of Chemistry. Institute of Chemical Sciences. Department of Radiochemistry and Environmental Chemistry; Polonia
Fil: Oleszczuki, P. Maria Curie-Skodowska University in Lublin. Faculty of Chemistry. Institute of Chemical Sciences. Department of Radiochemistry and Environmental Chemistry; Polonia
Fil: Czech, B. Maria Curie-Skodowska University in Lublin. Faculty of Chemistry. Institute of Chemical Sciences. Department of Radiochemistry and Environmental Chemistry; Polonia