BUSCADOR RECOLECTA

11 pages. -- Experimental and theoretical methods. -- Results., Peer reviewed

12 pages. -- Figure S1-S18. -- Table S1. Atomic percentages determined by XPS in the electrodes after OER. -- Table S2. Comparison of the CoFeP-based electrodes for OER in 1 M KOH in chronological order., The development of high current density anodes for the oxygen evolution reaction (OER) is fundamental to manufacturing practical and reliable electrochemical cells. In this work, we have developed a bimetallic electrocatalyst based on cobalt–iron oxyhydroxide that shows outstanding performance for water oxidation. Such a catalyst is obtained from cobalt–iron phosphide nanorods that serve as sacrificial structures for the formation of a bimetallic oxyhydroxide through phosphorous loss concomitantly to oxygen/hydroxide incorporation. CoFeP nanorods are synthesized using a scalable method using triphenyl phosphite as a phosphorous precursor. They are deposited without the use of binders on nickel foam to enable fast electron transport, a highly effective surface area, and a high density of active sites. The morphological and chemical transformation of the CoFeP nanoparticles is analyzed and compared with the monometallic cobalt phosphide in alkaline media and under anodic potentials. The resulting bimetallic electrode presents a Tafel slope as low as 42 mV dec–1 and low overpotentials for OER. For the first time, an anion exchange membrane electrolysis device with an integrated CoFeP-based anode was tested at a high current density of 1 A cm–2, demonstrating excellent stability and Faradaic efficiency near 100%. This work opens up a way for using metal phosphide-based anodes for practical fuel electrosynthesis devices., Peer reviewed

2 pages. -- Table 1 Compares the performance and cost estimation of two selected references and FeS2-decorated CNF., Peer reviewed

14 pages. -- 1. Synthesize and characterization on Cu1.5Te NPs. -- 2. Surface treatment with SeL solution. -- 3. Characterization on consolidated pellets. -- 4. High temperature XRD and TE properties. -- 5. Stability and repeatability. -- 6. Anisotropic characterizations. -- Figures S1-S18. -- Table S1. Refined lattice parameters (from Rietveld refinement of the XRD patterns) of different crystal structures at corresponding temperatures. -- Table S2. Relative densities of Cu1.5Te, Cu1.5-xTe-OL and Cu1.5-xTe-Cu2Se pellets obtained from absolute values measured with the Archimedes’ method., Cu2–xS and Cu2–xSe have recently been reported as promising thermoelectric (TE) materials for medium-temperature applications. In contrast, Cu2–xTe, another member of the copper chalcogenide family, typically exhibits low Seebeck coefficients that limit its potential to achieve a superior thermoelectric figure of merit, zT, particularly in the low-temperature range where this material could be effective. To address this, we investigated the TE performance of Cu1.5–xTe–Cu2Se nanocomposites by consolidating surface-engineered Cu1.5Te nanocrystals. This surface engineering strategy allows for precise adjustment of Cu/Te ratios and results in a reversible phase transition at around 600 K in Cu1.5–xTe–Cu2Se nanocomposites, as systematically confirmed by in situ high-temperature X-ray diffraction combined with differential scanning calorimetry analysis. The phase transition leads to a conversion from metallic-like to semiconducting-like TE properties. Additionally, a layer of Cu2Se generated around Cu1.5–xTe nanoparticles effectively inhibits Cu1.5–xTe grain growth, minimizing thermal conductivity and decreasing hole concentration. These properties indicate that copper telluride based compounds have a promising thermoelectric potential, translated into a high dimensionless zT of 1.3 at 560 K., Peer reviewed

17 pages. -- Characterization. -- Electrode preparation and electrochemical measurements. -- Density functional theory calculations. -- Figure S1-S17. -- Table S1. Elemental composition of ZnCo1.26Ni0.73Ox –SO4 before and after OER. -- Table S2. Assignment of FTIR characteristics peaks. -- Table S3. Comparison of OER activity of amorphous ZnCoxNiyOy-SO4 nanosheets with recently reported electrocatalysts in alkaline electrolyte. -- Table S4. Cdl and ECSAs of various catalysts. -- Table S5. Samples produced and characterized, including name, metal precursors type and nominal amount., Peer reviewed

19 pages. -- Characterization. -- Electrode preparation and electrochemical measurements. -- Theoretical method. -- Table S1. Complete list of samples produced and characterized, including name, precursors and processing conditions. -- Figures S1-S25. -- Table S2. Comparison of OER activity of obtained catalyst. -- Table S3. Cdl and ECSAs of various catalysts. -- Table S4. Simulated parameters from the relevant equivalent circuits. -- Table S5. OER activity of CoFexOy-SO4 and other Co-based catalysts in 1M KOH electrolyte., The electrochemical oxygen evolution reaction (OER) plays a fundamental role in several energy technologies, which performance and cost-effectiveness are in large part related to the used OER electrocatalyst. Herein, we detail the synthesis of cobalt-iron oxide nanosheets containing controlled amounts of well-anchored SO42– anionic groups (CoFexOy-SO4). We use a cobalt-based zeolitic imidazolate framework (ZIF-67) as the structural template and a cobalt source and Mohr’s salt ((NH4)2Fe(SO4)2·6H2O) as the source of iron and sulfate. When combining the ZIF-67 with ammonium iron sulfate, the protons produced by the ammonium ion hydrolysis (NH4+ + H2O = NH3·H2O + H+) etch the ZIF-67, dissociating its polyhedron structure, and form porous assemblies of two-dimensional nanostructures through a diffusion-controlled process. At the same time, iron ions partially replace cobalt within the structure, and SO42– ions are anchored on the material surface by exchange with organic ligands. As a result, ultrathin CoFexOy-SO4 nanosheets are obtained. The proposed synthetic procedure enables controlling the amount of Fe and SO4 ions and analyzing the effect of each element on the electrocatalytic activity. The optimized CoFexOy-SO4 material displays outstanding OER activity with a 10 mA cm–2 overpotential of 268 mV, a Tafel slope of 46.5 mV dec–1, and excellent stability during 62 h. This excellent performance is correlated to the material’s structural and chemical parameters. The assembled nanosheet structure is characterized by a large electrochemically active surface area, a high density of reaction sites, and fast electron transportation. Meanwhile, the introduction of iron increases the electrical conductivity of the catalysts and provides fast reaction sites with optimum bond energy and spin state for the adsorption of OER intermediates. The presence of sulfate ions at the catalyst surface modifies the electronic energy level of active sites, regulates the adsorption of intermediates to reduce the OER overpotential, and promotes the surface charge transfer, which accelerates the formation of oxygenated intermediates. Overall, the present work details the synthesis of a high-efficiency OER electrocatalyst and demonstrates the introduction of nonmetallic anionic groups as an excellent strategy to promote electrocatalytic activity in energy conversion technologies., Peer reviewed

16 pages. -- SEM-EDS characterization. -- HRTEM characterization. -- XPS spectra. -- Electrochemical characterization. -- EGOR Electrocatalytic performance comparision with previous results. -- Sample characterization after CA operation. -- IC Profile. -- Electrolytic cell coupling HER and EGOR. -- DFT data., Peer reviewed

20 pages. -- Experimental: Raw Materials. -- Modifications and Syntheses of Materials. -- Characterization techniques. -- Operando XRD Characterization. -- Batteries. -- Finite element simulations. Figures S1-S13 . -- Table S2. Interlayer distance (0 0 2) statistics of Gr and SC. -- Table S3. Definition of parameters of matrix polynomial for GrS electrode.. -- Table S4. Definition of parameters of matrix polynomial for SCS electrode., Peer reviewed

11 pages. -- Experimental Section. Chemicals. -- Synthesis of Hexaaminobenzene (HAB). -- Synthesis of C2N. --Synthesis of PdH0.58@C2N, Pd@C2N, PdH0.58 and PdH0.58/C2N. -- -- Structural characterization. -- Electrochemical Measurements. -- Computational method. -- Figures S1-S8. -- Table S1. Summary of the FOR activity and stability of Pd-based nanoalloys., The lack of electrocatalysts for the formate oxidation reaction (FOR) hampers the deployment of direct formate fuel cells (DFFCs). To overcome this limitation, herein, we detail the production of palladium hydride particles supported on C2N (PdH0.58@C2N) via a facile method. PdH0.58@C2N displays excellent FOR performance, reaching current densities up to 5.6 A·mgPd–1 and stable cycling and chronoamperometric operation. The Pd lattice expands due to the hydrogen intercalation. Besides, an electronic redistribution associated with the distinct electronegativity of Pd and H is observed. Both phenomena modify the electron energy levels, enhancing the activity and stability of the composite catalyst. More specifically, differential functional theory calculations show H intercalation to downshift the Pd d-band center in Pd0.58@C2N, weakening adsorbate binding and accelerating the FOR rate-determining step., Peer reviewed

26 pages. -- Fig. S1. XRD pattern of Cu(OH)2 collected from the sonication of the Cu(OH)2@CuM electrode. -- Fig. S2. XRD pattern of Ni(OH)2/Cu(OH)2 collected from the sonication of the Ni(OH)2/Cu(OH)2@CuM electrode. -- Fig. S3. XRD pattern of NiO/CuO collected from the sonication of the NiO/CuO@CuM electrode. -- Fig.S4. The diffraction spots pattern analysis of Fig 2c. -- Fig. S5. HRTEM images and corresponding indexed FFT of a NiO/CuO nanostructure. -- Fig. S6. HRTEM images and corresponding indexed FFT of a NiO/CuO nanostructure. -- Fig. S7. (a) SEM image of CuO@CuM. The inset shows an optical image of a self-supported electrode. (b) XRD pattern of CuO collected from the sonication of the CuO@CuM electrode. -- Fig. S8. HAADF STEM image and EELS elemental maps of Cu and O of CuO nanostructures. -- Fig. S9. SEM image of Ni(OH)2 directly grown on a copper mesh. The inset shows an optical image of the electrode. -- Fig. S10. SEM image of Ni(OH)2 directly grown on a CuM with the hydrothermal method. The inset shows an optical image of the electrode. (a) Hydrothermal method with the precursor of 1 mmol nickel nitrate, 2 mmol NaOH, 20 ml ethylene glycol and 4 ml H2O, as well as one piece of the cleaned CuM at 100 C for 300 min. (b) Hydrothermal method with the precursor of 1 mmol nickel acetylacetonate, 2 mmol urea, 1 mL butylamine, 20 ml ethylene glycol and 4 ml H2O as well as one piece of the cleaned CuM at 200 C for 180 min. -- Fig. S11. Survey XPS spectra of CuO@CuM and NiO/CuO@CuM. -- Fig. S12. Current density vs. urea concentration of NiO/CuO@CuM electrode at different specific applied potential. -- Fig. S13. LSV curves of NiO/CuO@CuM with the active process. -- Fig. S14. CV curves of (a) NiO/CuO@CuM, (b) Ni(OH)2/Cu(OH)2@CuM, (c) CuO@CuM, and (d) Cu(OH)2@CuM with different scan rates. -- Fig. S15. ECSA values of NiO/CuO@CuM, Ni(OH)2/Cu(OH)2@CuM, CuO@CuM, and Cu(OH)2@CuM electrode. -- Fig. S16. LSV curves of NiO/CuO@CuM electrode before and after stability measurements. -- Fig. S17. SEM image of NiO/CuO@CuM after stability measurements. -- Fig. S18. XRD pattern of NiO/CuO structure before and after stability tests. -- Fig. S19. (a) Cu 2p and (b) Ni 2p high-resolution XPS spectra of self-supported NiO/CuO@CuM electrodes after stability tests. -- Fig. S20. Raman spectra of NiO/CuO@CuM p-p heterojunction electrode (a) before and (b) after UOR stability test. -- Fig. 21. (a) SEM image of Ni(OH)2/CuO@CuM. (b) XRD pattern of Ni(OH)2/CuO nanostructure. (c) LSV curves (d) Tafel slopes of different electrodes in 1.0 M KOH with 0.5 M urea. (e) CV curves of Ni(OH)2/CuO@CuM electrode. (f) Cdl values of different electrodes. -- Fig. S22. (a) Top-view and (b) side-view of optimized structures of NiOOH/CuO heterojunction. -- Fig. S23. (a) Top-view and (b) side-view of optimized structures of NiOOH. (c) Top-view and (d) side-view of optimized structures of CuO. -- Fig. S24. PDOS and d band center of (a) pristine CuO, (b) NiOOH and (c) CuO/NiOOH heterojunctions with DFT+U (up) and DFT+U-D3 methods (down), respectively. -- Fig. S25. The slices of electron density difference of urea adsorbed on (a) pristine CuO, and (b) NiOOH. The contour around the atoms represents electron accumulation (red) or electron depletion (blue). The balls with various colors mean different atoms: red-O, gray-C, white-H, orange-Cu, dark blue-N, and watery blue-Ni. -- Fig. S26. (a) Bond length (Å) of urea molecule adsorbed on the NiOOH/CuO heterojunction surface. (b) Bond length (Å) of free urea molecule. -- Fig. S27. Slices of electron density difference of CO2 adsorbed on (a) pristine CuO, (b) NiOOH, and (c) NiOOH/CuO heterojunction. The contour around the atoms represents electron accumulation (red) or electron depletion (blue). The balls with various colors mean different atoms: red-O, gray-C, white-H, orange-Cu, and watery blue-Ni. -- Fig. S28. (a) The structure of DUFCs with an ion exchange membrane (IEM), (b) voltage-current and power-current curves of DUFCs with different self-supported anodes electrodes, (c) the open circuit voltage and (d) power density of DUFCs with different self-supported anodes electrodes. -- Table S1. The analysis results of the diffraction spots pattern of Fig. 2c. -- Table S2. Elements ratio of NiO/CuO@CuM and CuO@CuM by EDS and XPS techniques. -- Table S3. EIS fitting results of NiO/CuO@CuM, Ni(OH)2/Cu(OH)2@CuM, CuO@CuM and Cu(OH)2/@CuM. -- Table S4. Comparison of electrochemical UOR performance of this work with other reported electrodes. NF = nickel foam; GC = glassy carbon, CP = carbon paper, CC = carbon cloth. -- Table S5. Bond lengths of Cu-O and Ni-O at the bulk and heterojunction interface. -- Table S6. Comparison of DUFC performance with NiO/CuO@CuM as the anode and previously reported electrocatalysts., Peer reviewed