Examinando por Autor "Osorio Vargas, Paula"

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    Catalytic pyrolysis of used tires on noble-metal-based catalysts to obtain high-value chemicals: Reaction pathways
    (Elsevier B.V., 2022-07-01) Osorio Vargas, Paula; Campos, Cristian H.; Torres, Cecilia C.; Herrera, Carla; Shanmugaraj, Krishnamoorthy; Bustamante, Tatiana M.; Diaz de Leon, J.N.; Medina, Francisco; Arteaga Pérez, Luis E.
    A systematic study on the use of noble metals (Pd, Pt, Au) supported on titanate nanotubes (NT-Ti) for selectively producing BTX and p-cymene from waste tire pyrolysis is provided here. All the materials were characterized for chemical, textural and structural properties using a range of analytical techniques. The M/NT-Ti (M: Pd, Pt, or Au) catalysts exhibit low nanoparticle sizes (1.8 support > non-catalyst. The Py-GC/MS suggest that the catalysts participate in the secondary reactions of dealkylation, dehydrogenation, isomerization, aromatization, and cyclization leading to a higher formation of BTX than the uncatalyzed reaction. Finally, a comprehensive reaction pathway describing the catalytic pyrolysis of WT over Pd/NT-Ti was proposed by studying the catalytic pyrolysis of individual polymers constituting the waste tires, and D,L-Limonene. © 2021 Elsevier B.V.
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    TiO2 nanorods doped with g-C3N4 – Polyethylene composite coating for self-cleaning applications
    (Elsevier Ltd, 2022-09-01) Osorio Vargas, Paula; Pais Ospina, Daniel; Marin Silva, Diego A.; Pinotti, Adriana; Damonte, Laura; Cánneva, Antonela; Donadelli, Jorge A.; Pereira da Costa, Luiz; Pizzio, Luis R.; Torres, Cecilia C.; Campos, Cristian H.; Rengifo Herrera, Julián A.
    Visible-light-absorbing graphitic carbon nitride–TiO2 nanorod nanomaterials (g-C3N4@TiO2NR) were successfully immobilized using a one-step UVA-induced photocatalytic procedure on commercially obtained flexible low-density polyethylene (LDPE) films. Self-cleaning properties were evaluated in solid–liquid and solid–gas phases using malachite green as a model molecule under UV-A and visible light irradiation. For comparison purpose, LDPE films containing P25 TiO2 nanoparticles was prepared using the same synthetic strategy (P25/LDPE). Among the fabricated films, the g-C3N4@TiO2NR/LDPE films exhibited the highest photocatalytic activity both in solid–liquid and solid–gas phases after 120 min of visible light irradiation (λ > 455 nm) removing efficiently malachite green stains probably due to the attack of photoinduced reactive oxygen species (ROS) such as singlet oxygen (1O2), hydroxyl radical (•OH) and superoxide anion radical (O2−•). Furthermore, the g-C3N4@TiO2NR/LDPE films retained their visible-light-photoinduced photocatalytic properties after four reuse cycles. The g-C3N4@TiO2NR/LDPE films also exhibited significant visible-light-photoinduced hydrophilicity. The high visible-light-photoinduced photocatalytic capacity of g-C3N4@TiO2NR/LDPE films was found to be related to the textural and electronic properties, superior visible-light absorption, and surface roughness of the films. © 2022 Elsevier B.V.