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<p>In this work, 1, 2 and 3 wt % Ag were deposited on SBA-15 by the impregnation method to investigate the UV-assisted photocatalytic degradation of methyl orange (MO) and methylene blue (MB). The catalysts were characterized by atomic absorption spectroscopy (AAS), nitrogen physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV‒Vis diffuse reflectance spectroscopy. The XRD peaks at 38.7, 44.7, 65.0, 77.8 and 82.0° were identified as Ag<sup>0</sup>, which was confirmed via XPS. Decreasing bandgap energy values of 5.3, 3.5, 2.40 and 2.17&#xa0;eV were observed with increasing Ag wt % for SBA-15, 1Ag/SBA-15, 2Ag/SBA-15, and 3Ag/SBA-15, respectively. The best photocatalytic degradation was obtained with 2Ag/SBA-15, achieving 100% degradation for MO and MB in 30 and 45&#xa0;min, respectively. Consequently, the higher dispersion of Ag-NPs observed in the TEM micrographs could be explained. Ag<sup>0</sup> acted as both an electron trap and a plasmonic sensitizer, which suppressed electron‒hole recombination. Pseudo-first-order kinetics were observed in the photocatalytic process for all four catalysts evaluated, reaching the highest constants for the 2Ag/SBA-15 catalyst, with values of 0.1458 and 0.1872&#xa0;min<sup>−1</sup> for MB and MO, respectively. Hydroxyl radicals (•OH) are crucial for the degradation of both dyes, and the 2Ag/SBA-15 catalyst was still stable after five cycles.</p>

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Photocatalytic activity of metallic silver supported on SBA-15 for the degradation of methyl orange and methylene blue

  • 期刊论文

  • 发表日期：

    2026年1月31日

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  • Diana Gabriela Domínguez-Talamantes,
  • Enrique Rodríguez-Castellón,
  • Judith Celina Tánori-Córdova,
  • Arturo García-Bórquez,
  • Maribel Ovando-Martínez,
  • Claudia Celeste Molina-Domínguez,
  • Nohemí Gámez-Meza,
  • Diana Vargas-Hernández

摘要

In this work, 1, 2 and 3 wt % Ag were deposited on SBA-15 by the impregnation method to investigate the UV-assisted photocatalytic degradation of methyl orange (MO) and methylene blue (MB). The catalysts were characterized by atomic absorption spectroscopy (AAS), nitrogen physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV‒Vis diffuse reflectance spectroscopy. The XRD peaks at 38.7, 44.7, 65.0, 77.8 and 82.0° were identified as Ag0, which was confirmed via XPS. Decreasing bandgap energy values of 5.3, 3.5, 2.40 and 2.17 eV were observed with increasing Ag wt % for SBA-15, 1Ag/SBA-15, 2Ag/SBA-15, and 3Ag/SBA-15, respectively. The best photocatalytic degradation was obtained with 2Ag/SBA-15, achieving 100% degradation for MO and MB in 30 and 45 min, respectively. Consequently, the higher dispersion of Ag-NPs observed in the TEM micrographs could be explained. Ag0 acted as both an electron trap and a plasmonic sensitizer, which suppressed electron‒hole recombination. Pseudo-first-order kinetics were observed in the photocatalytic process for all four catalysts evaluated, reaching the highest constants for the 2Ag/SBA-15 catalyst, with values of 0.1458 and 0.1872 min−1 for MB and MO, respectively. Hydroxyl radicals (•OH) are crucial for the degradation of both dyes, and the 2Ag/SBA-15 catalyst was still stable after five cycles.