Examinando por Autor "Torres-Pardo, Almudena"

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Influence of Cation Substitution on the Complex Structure andLuminescent Properties of the ZnkIn2Ok+3System
(ACS Publications, 2020-06-25) García-Fernández, Javier; Torres-Pardo, Almudena; Bartolomé, Javier; Martínez-Casado, Ruth; Zhang, Qing; Ramírez-Castellanos, Julio; Terasaki, Osamu; Cremades, Ana; González-Calbet, Jose María
The effect of In3+ substitution by Ga3+ or Al3+ on the structure and luminescent properties of Zn7In2–xMxO10 (M = Ga or Al; 0 ≤ x ≤ 1) oxides has been investigated by means of high spatial resolution X-ray spectroscopy and high-angle annular dark-field images, combined with magic angle spinning nuclear magnetic resonance spectroscopy. Local structural variations have been identified for the Al- and Ga-doped samples through the analysis of atomically resolved chemical maps and the identification of their structural environment within the wurtzite lattice. In3+ is distributed in a zig-zag modulation, while Al3+ and Ga3+ are located in a flat distribution at the center of the wurtzite block. Density functional theory calculations provide unambiguous evidence for the preferential flat location of Ga3+ and Al3+ associated with the different strains introduced in the structure as a result of their ionic radii. The characterization of the photoluminescence response reveals the appearance of new radiative recombination pathways for the doped materials because of the presence of new defect levels in the band gap of the Zn7In2O10 structure.
Innovative ternary composite photocatalyst: BiOCl/Bi12O17Cl2/Bi2O3 for sustainable water remediation
(Elsevier, 2024-07-01) Pérez del Pulgar, Helena; Ortiz-Bustos, Josefa; Torres-Pardo, Almudena; Parras, Marina; Hierro, Isabel del; Pérez, Yolanda
The presence of pollutants in aquatic environments is causing severe health effects on both humans and animals. To address this issue, it has become crucial to develop more efficient and environmentally friendly photocatalysts for the removal of persistent pollutant mixtures from water. In this context, photocatalysts containing more than two bismuth-based materials have rarely been explored for water remediation. With this in mind, we propose an innovative ternary composite, BiOCl-1/Bi12O17Cl2/Bi2O3, as a potentially sustainable visible light-active photocatalyst. Firstly, bismuth oxychloride has been prepared in the presence of ionic liquid, leading to the formation of BiOCl-1 with highly reactive {1 1 0} facets. Subsequently, the construction of the ternary composite has been accomplished using a facile and soft hydrothermal approach. The as-prepared BiOCl-1/Bi12O17Cl2/Bi2O3 composite has been successfully used in degrading binary mixtures of contaminants (i.e. ciprofloxacin, methylparaben or methyl orange), achieving an improved visible-light photocatalytic activity compared to single BiOCl-1 and other previously reported bismuth-based photocatalysts. In addition, the photocatalytic mechanism and degradation pathways have been elucidated through scavenger and electrochemical experiments, as well as chromatography-mass spectrometry (LC-MS) analysis, respectively