Resultados de investigación

Additional experimental details on electrode preparation, cell configuration, analytical results, and efficiency calculations, additional results: EDX analysis, EPR spectroscopy, and XRD analysis, and additional results of galvanostatic and cycling tests, Electrochemical ammonia synthesis from nitrate can complement a hydrogen-based energy system with a liquid, shippable energy carrier. Ammonia (NH3) is attractive because it serves both as an energy vector and as an essential feedstock. However, nitrate reduction is an eight-electron, proton-coupled pathway that forms multiple intermediates; the NO3– → NO2– step is widely viewed as rate-determining, followed by nitrite reduction and hydrogenation steps, until the formation of NH3. Here, we implement a tandem strategy in a flow cell using a double-sided electrode with Cu and TiO2@Cu surfaces that cooperatively boost the NO3– → NO2– and NO2– → NH3 conversions. The system achieves a Faradaic efficiency toward NH3 of 97%, with an NH3 selectivity of 80%, and a productivity of 7.7 mg h–1 cm–2 (0.45 mmol h–1 cm–2), corresponding to a full-cell energy efficiency of 29%. This integrated electrode–reactor design expands the accessible performance space for the NO3RR by combining nitrate adsorption with selective nitrite hydrogenation. These results establish a practical route for the efficient electrochemical synthesis of NH3 from nitrate., Peer reviewed

This PDF file includes: Figs. S1 to S26. -- Tables S1 to S4, Peer reviewed

Electrochemical valorization of biomass-derived glucose offers a promising route for the sustainable coproduction of valuable chemicals and green hydrogen, yet hinges on the development of cost-effective, multifunctional catalysts. Here, we report a noble metal-free core–shell catalyst, Cu@CoFe2O4, that drives both anodic glucose oxidation and cathodic hydrogen evolution or glucose hydrogenation in a single system. In alkaline media (1 M KOH), the catalyst achieves a glucose conversion of 97.5% with a Faradaic efficiency (FE) of 91.2% toward formate at 1.3 V vs RHE, while enabling hydrogen evolution with 100% FE. In a neutral electrolyte (0.1 M Na2SO4), the same electrode facilitates the selective electrochemical reduction of glucose to sorbitol with an FE of 87.5% and 76% conversion at −0.4 V vs RHE. Experimental and computational analyses suggest that the Cu-rich core/CoFe2O4-rich shell-like heterostructure enhances charge transfer and provides complementary active sites, contributing to the observed activity toward both glucose oxidation and hydrogenation pathways. This work highlights a versatile, earth-abundant electrocatalytic platform for biomass conversion and sustainable hydrogen generation., Peer reviewed

This repository contains experimental data, scripts used for the data analysis, scripts used for the numerical calculation and the microscopy analysis for the following paper: "Majorana-like Coulomb spectroscopy in the absence of zero bias peaks"., Peer reviewed

29 pages. -- Content: The tracking process of adsorption of CdSe species on the SnSe surface; XRD patterns of SnSe and SnSe-x%CdSe nanocomposites; SEM images of SnSe-3%CdSe nanocomposites at the different stages; SEM images of annealed SnSe-x%CdSe nanopowders; Grain size evolution study for bare SnSe and SnSe-3%CdSe; SEM images at different magnifications of SnSe and SnSe-3%CdSe pellets; EBSD microstructure of SnSe and SnSe-3%CdSe pellets; XRD pattern of recrystallized CdSe; SEM images of annealed SnSe powder at 350°C; EDS elemental mapping for SnSe-3%CdSe; Surface treatment; Thermogravimetric analyses; SnSe-CdSe phase diagram; High-temperature XRD analyses of SnSe and SnSe-3%CdSe; Lattice parameters and unit cell volume of SnSe-3%PbS pellet; TE properties of SnSe-CdSe samples with different content of CdSe; Band structure changes in SnSe induced by the CdSe NPs; TE properties of SnSe and SnSe-3%CdSe measured in parallel direction; Heat capacity Cp of SnSe-3%CdSe; Percentage variations in the TE properties of SnSe-x%CdSe compared to SnSe; Lattice thermal conductivity (κL) calculation; Literature comparison; TEM images of SnSe-3%CdSe sample; Material stability and repeatability; Cylindrical pellet cutting; Theoretical zT prediction; Pellet density and composition; References., SnSe has emerged as one of the most promising materials for thermoelectric energy conversion due to its extraordinary performance in its single-crystal form and its low-cost constituent elements. However, to achieve an economic impact, the polycrystalline counterpart needs to replicate the performance of the single crystal. Herein, we optimize the thermoelectric performance of polycrystalline SnSe produced by consolidating solution-processed and surface-engineered SnSe particles. In particular, the SnSe particles are coated with CdSe molecular complexes that crystallize during the sintering process, forming CdSe nanoparticles. The presence of CdSe nanoparticles inhibits SnSe grain growth during the consolidation step due to Zener pinning, yielding a material with a high density of grain boundaries. Moreover, the resulting SnSe–CdSe nanocomposites present a large number of defects at different length scales, which significantly reduce the thermal conductivity. The produced SnSe–CdSe nanocomposites exhibit thermoelectric figures of merit up to 2.2 at 786 K, which is among the highest reported for solution-processed SnSe., Peer reviewed

10 pages. -- Figures and tables. -- Figure S1: SEM image of (a) bulk g-C3N4 and (b) ultrathin g-C3N4, (c) N2 adsorption-desorption isotherms of bCN and uCN. -- Figure S2: FTIR spectra of OAC, OLMA and TiO2 before and after ligands remove. -- Figure S3: Zeta potential distribution spectrum of TiO2 after ligands removal (a) and uCN (b). -- Figure S4: SEM image and EDS compositional maps of a T1/uCN1 composite. -- Figure S5: SEM image of T1/uCN2 and corresponding EDS spectrum. -- Figure S6: SEM image of T1/uCN2 and corresponding EDS spectrum. -- Figure S7: SEM image of T1/uCN2 and corresponding EDS spectrum; Figure S8: Chromatogram plots for 0.5 ml of standard hydrogen injected every half hour. -- Table S1: Gas Chromatography Peak Processing Data based on figure S8. -- Figure S9: Standard hydrogen curve for gas chromatography. -- Table S2: Exponential decay-fitted parameters of fluorescence lifetime of uCN, TiO2 and T1/uCN1. -- Figure S10: Photocatalytic hydrogen generation amount on bCN, TiO2 and T1/bCN1 during 4 h under simulated solar light irradiation; Table S3: Photocatalytic hydrogen production about TiO2/g-C3N4 based catalysts. -- Table S4: The AQE values with different incident light wavelengths for T1/uCN1. -- Figure S11: (a) Stability cycles of the T1/uCN1 for H2 evolution under simulated solar light irradiation; (b) TEM image of T1/uCN1 after 20 h photocatalytic H2 evolution reaction and (c) XRD pattern of T1/uCN1 before and after 20 h photocatalytic H2O2 evolution reaction., CN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706) and is funded by the CERCAProgramme / Generalitat de Catalunya., Peer reviewed

16 pages. -- Scheme S1. Scheme of the synthesis of Co-TAA. -- Figure S1. FT-IR spectra of the model compound Co-TAA, and Poly-TAA-Co powder. -- Figure S2. (a-b) HRTEM images and (c-d) STEM images of Poly-TAA-Co. -- Figure S3. EELS chemical composition maps from the red squared area of the STEM micrograph. Individual Co L2,3-edges at 779 eV (red), N K-edges at 401 eV (green), O K-edges at 532 eV (blue), and C-K edges at 284 eV (grey) and composites of Co-N, Co-O, Co-C, N-O and Co-N-C. -- Figure S4. (a)-(b) Survey, high resolution C1s XPS spectra of Poly-TAA powder, respectively. -- Figure S5. (a) Survey, high resolution C1s XPS spectra of Poly-TAA-Co powder, respectively. -- Figure S6 TGA analysis of Poly-TAA-Co under argon by heating to 600 ℃ at the rate of 5 ℃/min. -- Table S1. Co K-edge EXAFS fitting parameters for Poly-TAA-Co. -- Figure S7. N2 adsorption and desorption of Poly-TAA (a), Poly-TAA-Co (b) and Poly-TAA-Co-CNT (c), respectively. -- Figure S8. (a) Total current density of Poly-TAA-Co-CNT (7:3). (b) FE of CO and H2 at various potentials for Poly-TAA-Co-CNT (7:3). -- Figure S9 Current density for H2 production on Poly-TAA-Co-CNT(1:1) and Poly-TAA-Co-CNT(3:7). and. -- Figure S10. Nyquist plots of the electrochemical impedance spectroscopy (EIS) data of (a) Poly-TAA-Co, (b) Poly-TAA-Co-CNT(1:1) and Poly-TAA-Co-CNT(3:7) electrodes after the activation process. -- Figure S11. Linear sweep voltammetry (LSV) curves of (a) Poly-TAA-Co. -- Figure S12. FE of H2 at various potentials on Co-TAA-CNT(3:7), CoPc-CNT(3:7) and Poly-TAA-Co-CNT(3:7). -- Figure S13. XRD patterns of Poly-TAA-Co-CNT loaded on carbon paper before and after CO2RR. -- Figure S14 HAADF-STEM (a, c), BF-TEM (b, d) and HRTEM micrographs (c, e) of Poly-TAA-Co-CNT (3:7) sample (before and after CO2RR). -- Figure S15. EELS chemical composition maps obtained from the red squared area of the STEM micrograph. Individual Co L2,3-edges at 779 eV (red), N K-edges at 401 eV (green), O K-edges at 532 eV (blue), and C-K edges at 284 eV (grey) and composites of Co-N, Co-O, Co-C, N-O and Co-N-C. (Poly-TAA-Co-CNT (3:7), after electrocatalytic CO2RR). -- Figure S16. Calculated energy diagrams for CO2 to CO at －0.5 V conversion on CoPc and CoTAA molecule, respectively. -- Table S2. The comparison of electrochemical reduction of CO2 to CO for reported cobalt based electrocatalysts., ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706) and ICN2 and IREC are funded by the CERCA Programme /Generalitat de Catalunya., Peer reviewed

11 pages. -- PDF files includes: Experimental section; Photocatalytic experiment; Synthesis of GDY powder; Preparation of CuO/GDY/TiO2 and GDY/TiO2; Preparation of Pt loaded TiO2, tables and figures. -- Figure S1. The prepared GDY powder by using deprotection-free method. -- Table S1. Screening of catalysts and solvents for the direct coupling reaction of HEB-TMS. + entry 15 was performed under Ar conditions. -- Figure S2. GC-MS spectra of the DMF solution after reaction (balck line) and the standard curve of the corresponding compound (red line). -- Figure S3. ICP-Mass results for content of Cu in the prepared CuO/GDY samples. -- Figure S4. Low- and high-magnification SEM images of the prepared CuO/GDY samples. -- Figure S5. 1*1*1 unit crystal model of CuO and atomic supercell model illustration of the CuO nanoparticle oriented as in TEM images. -- Table S2. Comparison between the experimental and the theoretical bulk plane spacing distances and angles between planes. -- Figure S6. High-resolution XPS spectra of Si in GDY. -- Table S3. The atomic percentage of different elements in pure GDY. -- Figure S7. XRD spectra of TiO2 and CuO/GDY/TiO2 with different content. -- Figure S8. (a) Raman spectra and (b) enlarged spectra of TiO2 and CuO/GDY/TiO2 with different content. - -Figure S9. (a) the full XPS spectra of TiO2 and CuO/GDY/TiO2; (b) high-resolution XPS spectra of Cu in CuO/GDY/TiO2. -- Figure S10. UV-Vis spectra of TiO2 and CuO/GDY/TiO2 with different content. -- Figure S11. photocurrent test of CuO/GDY/TiO2, GDY/TiO2, CNT/TiO2 and GR/TiO2. -- Figure S12. Tauc plot of the prepared GDY powder. -- Figure S13. Valence band spectra of the prepared GDY powder by XPS. -- Figure S14. (a) High-resolution XPS spectra of Cu in CuO/GDY/TiO2 before and after photocatalysis; (b) fitting of Cu in in CuO/GDY/TiO2 after photocatalysis. In comparison, the satellite observed for Cu 2p (corresponding to Cu2+) is significantly reduced after illumination. -- Figure S15. The proposed photocatalytic mechanism of the CuO/GDY/TiO2 photocatalysts., Peer reviewed

20 pages. -- PDF file includes S1. Substrate fabrication and growth details; S2. Degradation of surface topography after thermal oxide removal prior nanowire growth; S3. Faceting of GaAs(Sb) vs GaAs nanowires; S4. The role of InGaAs growth temperature; S5. The role of InAs growth temperature; S6. InAs/InGaAs field effect mobility measurements: influence of the InGaAs buffer growth temperature; S7. InAs/InGaAs band structure simulations; S8. Transport measurements of InGaAs/GaAs(Sb) SAG nanowires without the InAs channel; S9. InAs/InGaAs field effect mobility measurements: influence of the InAs growth temperature, figures and tables., ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant No. SEV-2017-0706) and is funded by the CERCA Programme/Generalitat de Catalunya., Peer reviewed

11 pages. -- PDF includes: 1. Experimental section; 2. Cyclic voltammetries measurements; 3. Morphological and structural characterisation data from SEM, DRX, TEM, SAED and STEM; 4. Electrochemical characterisation data by impedance spectroscopy, figures and tables., ICN2 is supported by the Severo Ochoa program from Spanish MINECO (Grant no. SEV-2017-0706) and is funded by the CERCA Programme/Generalitat de Catalunya., Peer reviewed