Browsing by Author "Barrientos, Lorena"
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- ItemCatalytic activity of iron phthalocyanine for the oxidation of thiocyanate and L-cysteine anchored on Au(111) clusters(2019) Castro Latorre, Pablo; Miranda Rojas, Sebastián; Barrientos, Lorena; Mendizabal, Fernando
- ItemControlled Ag-tio2 heterojunction obtained by combining physical vapor deposition and bifunctional surface modifiers(2018) Barrientos, Lorena; Allende, Patricio; Angel Laguna-Bercero, Miguel; Pastrian, Juan; Rodriguez-Becerra, Jorge; Caceres-Jensen, Lizethly
- ItemFormation of Copper Nanoparticles Supported onto Inclusion Compounds of alpha-cyclodextrin: A New Route to Obtain Copper Nanoparticles(2010) Silva, Nataly; Moris, Silvana; Herrera Pisani, Bárbara Andrea; Diaz, Maximiliano; Kogan, Marcelo J.; Barrientos, Lorena; Yutronic, Nicolas; Jara, Paul
- ItemIdentification of potential trypanothione reductase inhibitors among commercially available beta-carboline derivatives using chemical space, lead-like and drug-like filters, pharmacophore models and molecular docking(2017) Rodriguez, J.; Caceres, L.; Hernandez, J.; Barrientos, Lorena
- ItemInclusion compounds of alpha-cyclodextrin with alkylthiols(2008) Jara, Paul; Barrientos, Lorena; Herrera Pisani, Bárbara Andrea; Sobrados, Isabel
- ItemPedagogical Content Knowledge of Chemical Kinetics: Experiment Selection Criteria To Address Students’ Intuitive Conceptions(2018) Marzabal Blancafort, Ainoa; Delgado Chang, Virginia; Moreira Seguel, Patricia Magdalena; Barrientos, Lorena; Moreno Cortes, Jeannette del Pilar
- ItemRole of Nb2O5 Crystal Phases on the Photocatalytic Conversion of Lignin Model Molecules and Selectivity for Value‐Added Products(2024) Rojas de la Fuente, Susana Dennis; Rafaela, Gabriela; Espinoza Villalobos, Nicole Margarita; Díaz, Donovan; Salazar, Ricardo; Cáceres Jensen, Lizethly; Escalona, Néstor; Barrientos, LorenaThe photocatalytic conversion in aqueous media of phenol and guaiacol as a lignin model compound using Nb2O5 with different crystal phases was studied. Nb2O5 particles were synthesized using hydrothermal methods, where it was observed that changes in the solvent control their morphology and crystal phase. Different photocatalytic behavior of Nb2O5 was observed with the selected model compounds, indicating that its selection directly impacts the resulting conversion and selectivity rates as well as the reaction pathway, highlighting the relevance of model molecule selection. Photocatalytic conversion of phenol showed conversion rate (C%) up to 25 % after 2 h irradiation and high selectivity (S%) to pyrogallol (up to 50 %). Orthorhombic Nb2O5 spheres favored conversion through free hydroxyl radicals while monoclinic rods did not convert phenol. Guaiacol photocatalytic oxidation showed high conversion rate but lower selectivity. Orthorhombic and monoclinic Nb2O5 favored the formation of resorcinol with S % ~0.43 % (C % ~33 %) and ~13 % (C % ~27 %) respectively. The mixture of both phases enhanced the guaiacol conversion rate to ~55 % with ~17 % of selectivity to salicylaldehyde. The use of radical scavengers provided information to elucidate the reaction pathway for these model compounds, showing that different reaction pathways may be obtained for the same photocatalyst if the model compound is changed.
- ItemSelective photocatalytic conversion of guaiacol using g-C3N4 metal free nanosheets photocatalyst to add-value products(ELSEVIER SCIENCE SA, 2021) Rojas de la Fuente, Susana Dennis; Espinoza Villalobos, Nicole Margarita; Salazar, R.; Escalona, Néstor; Contreras, D.; Melin, V; Laguna Bercero, M. A.; Sanchez Arenillas, M.; Vergara, E.; Caceres Jensen, L.; Rodríguez Becerra, J.; Barrientos, LorenaValorization of lignin into high valuable chemical is a critical challenge. Its availability is a key factor for the development of viable lignocellulosic processes to replace fossil derived compounds. In this work, new insights on the high photocatalytic conversion of guaiacol (82%) as a lignin model compound was achieved, also, high selectivity to p-benzoquinone (59%), catechol (27%), and pyrogallol (6%) was obtained using metal-free pyrolyzed g-C3N4 under visible light irradiation. To highlight the new insights, experimental parameters were modified to control the reaction mechanism to increase selectivity and photo-conversion. g-C3N4 photocatalyst was synthesized through urea calcination at 550 degrees C and the photocatalytic performance was assessed in terms of pyrolysis time, where higher time resulted in better photocatalytic activity. This effect was attributed to smaller structures and therefore better quantum confinement of the charges. The oxidation was promoted by OH radicals, which were detected through EPR operando mode and the addition of radical scavengers. A reaction pathway was proposed, in which the OH attacks guaiacol through a methoxy group. The photocatalytic reaction can be tuned using external oxidant agents such as O-2 and/or H2O2 to promote certain radical formation, enhancing conversion rates and promoting selectivity for a specific product, where yield shifting from p-benzoquinone to pyrogallol was experimentally observed.
- ItemSilver /Silver oxide nanoparticles as potential sensitizers in dye-sensitized solar cells(2010) Barrientos, Lorena; Loeb Luschow, Bárbara
- ItemSolid state tuning of TiO2 morphology, crystal phase, and size through metal macromolecular complexes and its significance in the photocatalytic response(2018) Allende-Gonzalez, P.; Laguna Bercero, M.A.; Barrientos, Lorena; Valenzuela, M.L.; Diaz, C.
- ItemSolvent-less method for efficient photocatalytic alpha-Fe2O3 nanoparticles using macromolecular polymeric precursors(2016) Diaz, Carlos; Barrientos, Lorena; Carrillo, Daniel; Valdebenito, Javier; Valenzuela, María L.; Allende, Patricio; Geaney, Hugh; O'Dwyer, Colm
- ItemSynthesis, spectroscopic and electrochemical characterization of copper(I) complexes with functionalized pyrazino[2,3-f]-1,10-phenanthroline(2008) Barrientos, Lorena; Araneda, Carmen; Loeb Luschow, Bárbara; Crivelli, Irma G.
- ItemTiO2/SiO2 Composite for Efficient Protection of UVA and UVB Rays Through of a Solvent-Less Synthesis(2019) Allende, P.; Barrientos, Lorena; Orera, A.; Laguna Bercero, M. A.; Salazar, N.; Valenzuela, M. L.; Díaz, C.
- ItemTuning amphiphilic properties of Ni/Carbon nanotubes functionalized catalysts and their effect as emulsion stabilizer for biomass-derived furfural upgrading(2020) Herrera, C.; Barrientos, Lorena; Rosenkranz, Andreas; Sepulveda, C.; Garcia-Fierro, J. L.; Laguna-Bercero, M. A.; Escalona, Néstor
- ItemValorization of biomass derivatives through the conversion of phenol over silica-supported Mo-Re oxide catalysts(2020) Herrera Hernández, Carla Pía; Ghampson, IT; Cruces, K; Sepulveda, C; Barrientos, Lorena; Laurenti, D; Geantet, C; Serpell Carriquiry, Ricardo Javier; Contreras, D; Melin, V; Escalona, N