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Scientific Papers in SCI



2023


Química de Superficies y Catálisis

Scalable synthesis of 2D Ti2CTx MXene and molybdenum disulfide composites with excellent microwave absorbing performance

Miao, BJ; Cao, YE; Zhu, QS; Nawaz, MA; Ordiozola, JA; Reina, TR; Bai, ZM; Ren, JN; Wei, FC
Advanced Composites and Hybrid Materials, 6 (2023) 61

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The signal crosstalk and electromagnetic interference (EMI) problems direly need to be resolved in the rapid development of modern microwave communication technology for a better working frequency and transmission power of electronic systems. Where the new absorbing materials such as molybdenum disulfide (MoS2)/titania (TiO2)/Ti2CTx and MoS2/Ti2CTx composites could meet the requirement of "thin, strong, light weight, and wide band" for excellent absorbing performance. In this work, a lighter Ti2CTx material was selected as the matrix, and MoS2 was in-situ grown on Ti2CTx matrix by traditional hydrothermal method and microwave solvothermal method. The fabricated composite exhibited synergic effect of two-dimensional heterostructural interface and double dielectric elements, where a small amount of TiO2 and a certain proportion of MoS2 jointly improve the impedance matching of the composite material. In here, the extreme reflection loss (RLmin) can reach - 54.70 dB (with a frequency of 7.59 GHz, 3.39 mm thickness), and the maximum effective absorption bandwidth (EAB(max)) can reach 4 GHz. Polyethylene glycol 200 was used as the solvent instead of water to make Ti2CTx less oxidized during the composite process, where the microwave heating would attain fast speed, short time, high efficiency, and uniform product. Since, the MoS2/Ti2CTx composite without oxidizing possessed a wider effective absorption bandwidth (EAB) at a thinner thickness, thus resulting in the excellent microwave absorption performance and confirming the validity and rationality of new microwave absorption materials.


April, 2023 | DOI: 10.1007/s42114-023-00643-2

Materiales y Procesos Catalíticos de Interés Ambiental y Energético

High-Performance Photocatalytic H2 Production Using a Binary Cu/ TiO2/SrTiO3 Heterojunction

Gonzalez-Tejero, M; Villachica-Llamosas, JG; Ruiz-Aguirre, A; Colon, G
ACS Applied Energy Materials, 6 (2023) 4007-4015

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Cu/TiO2/SrTiO3 hybrid structures have been synthesized by the simple impregnation method from Cu/TiO2 and SrTiO3 systems. The structural and surface characterization stated that Cu/TiO2/SrTiO3 composites form an effective covering of SrTiO3 by Cu/TiO2. The heterostructured catalysts lead to an outstanding improved photoactivity for hydrogen production from methanol photoreforming that would be related with the efficient separation of charge pairs favored by the Cu/ TiO2/SrTiO3 heterojunction. The best photoproduction is attained for the 30 wt % SrTiO3 heterojunction showing 81.7 mmol/g H2 after 6 h (leading to an apparent quantum yield of ca 1%), 1.7 times higher than that of bare Cu/TiO2.


April, 2023 | DOI: 10.1021/acsaem.3c00219

Reactividad de Sólidos

Large-scale oxygen-enriched air (OEA) production from polymeric membranes for partial oxycombustion processes

Garcia-Luna, S; Ortiz, C; Chacartegui, R; Perez-Maqueda, LA
Energy, 268 (2023) 126697

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Partial oxycombustion using Oxygen-Enriched Air (OEA), produced by air-gas separation with polymeric membranes, combined synergistically with CO2 capture technologies, can reduce the overall energy cost of CO2 capture, and it is a potential alternative to conventional CO2 capture technologies. An exhaustive review of polymeric membranes for this application is presented. The best membranes showed permeability values in the 450-25,100 barrer and selectivities higher than 3.6 for large-scale operations. These membranes can produce OEA with oxygen molar concentrations of up to 40% for retrofitting large-scale power plants (similar to 500 MWe) with partial oxycombustion. For OEA production, the polymeric membrane system is more efficient than cryogenic distillation since the specific power consumption of the former is 35.17 kWh/ton OEA. In comparison, that of the latter is 49.57 kWh/ton OEA. This work proposes that the OEA produced by the membranes feed a partial oxycombustion process integrated with calcium looping within a hybrid CO2 capture system. The power con-sumption of the hybrid CO2 capture system proposed here is 29.05% lower than in the case OEA is produced from cryogenic distillation, which justifies the potential interest in using polymeric membranes for OEA production.


April, 2023 | DOI: 10.1016/j.energy.2023.126697

Fotocatálisis Heterogénea: Aplicaciones

Photocatalytic treatment based on TiO2 for a coal mining drainage

Murcia-Mesa, JJ; Patino-Castillo, CG; Rojas-Sarmiento, HA; Navio-Santos, A; Hidalgo-Lopez, MD; Angel-Botero, A
Revista Facultad de Ingeniería-Universidad de Antioquia, 107 (2023) 88-101

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The aim of the present work was to evaluate the effectiveness of a heterogeneous photocatalyst based on TiO2 in the treatment of coal mining drainage which contains a variety of heavy metals and high concentration sulfates and sulfides. The photocatalytic behavior of the commercial reference Sigma Aldrich and the different materials synthesized using the Sol-gel methodology with surface modifications using sulfation and fluorination processes were analyzed. To find a possible correlation between the physicochemical properties of photocatalysts and their behavior, a characterization was carried out using X-Ray Diffraction (XRD), X-Ray Fluorescence spectrometry (XRF), Fourier transform infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance Spectra (UV-Vis DRS), N2 physisorption, X-ray photoelectron spectroscopy (XPS), and particle size analysis. Results indicated that the modification of the TiO2 prepared in the laboratory using sulfation and fluorination allowed the successful control of the physicochemical properties of this oxide. However, commercial TiO2 showed the greatest effectiveness in removing metals such as: Fe, Cu, Cr, and As after a photocatalytic reaction for a maximum of 1 hour under continuous nitrogen flow and a light intensity of 120 W/m2.


April, 2023 | DOI: 10.17533/udea.redin.20211063

Química de Superficies y Catálisis

In-situ DRIFTS steady-state study of CO2 and CO methanation over Ni-promoted catalysts

González-Castaño, M; González-Arias, J; Bobadilla, LF; Ruíz-López, E; Odriozola, JA; Arellano-García, H
Fuel, 338 (2023) 127241

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Promoting the performance of catalytic systems by incorporating small amount of alkali has been proved effective for several reactions whilst controversial outcomes are reported for the synthetic natural gas production. This work studies a series of Ni catalysts for CO2 and CO methanation reactions. In-situ DRIFTS spectroscopy evidenced similar reaction intermediates for all evaluated systems and it is proposed a reaction mechanism based on: i) formate decomposition and ii) hydrogenation of lineal carbonyl species to methane. Compared to bare Ni, the enhanced CO2 methanation rates attained by NiFe/Al and NiFeK/Al systems are associated to promoted formates decomposition into lineal carbonyl species. Also for CO methanation, the differences in the catalysts' performances were associated to the relative concentration of lineal carbonyl species. Under CO methanation conditions and opposing the CO2 methanation results where the incorporation of K delivered promoted catalytic behaviours, worsened CO methanation rates were discerned for the NiFeK/Al system.


April, 2023 | DOI: 10.1016/j.fuel.2022.127241

 

 

 

 

 

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