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Maria Jazmin Duarte

Publications and source records attributed to Maria Jazmin Duarte.

2 recordsLinked to original sources

Self-supported bulk MXene electrodes for electrochemical hydrogen applications

MXenes are promising candidates for electrochemical applications due to their high conductivity, tunable surface chemistry, and catalytic potential. However, their use in bulk electrode form remains unexplored despite advantages such as higher current density and improved mechanical integrity. Herein, we present a methodology for the fabrication of self-supported vdW solid Ti3C2Tz MXene electrodes, produced by cold compaction followed by vacuum heat treatment at 600 {\deg}C, which effectively removes interlayer confined water and stabilizes the bulk 3D structure. The resulting binder-free electrodes exhibit enhanced mechanical robustness along with structural and chemical stability in various electrolytes. The MXene electrodes demonstrate adequate HER activity while maintaining electrochemical stability over time, with minimal oxidation or changes in termination surface chemistry. This approach is scalable and cost-effective, overcoming limitations of nanoscale MXene architectures in electrochemical environments and offering a practical pathway toward MXene-based materials for sustainable hydrogen energy technologies.

cond-mat.mtrl-sci

Microstructural features and hydrogen diffusion in bcc FeCr alloys: a comparison between the Kelvin probe- and nanohardness based- methods

Hydrogen embrittlement can result in a sudden failure in metallic materials, which is particularly harmful in industrially relevant alloys, such as steels. A more comprehensive understanding of hydrogen interactions with microstructural features is critical for preventing hydrogen-induced damage and promoting a hydrogen-based environment-benign economy. We use the Kelvin probe-based potentiometric hydrogen electrode method and thermal desorption spectroscopy to investigate hydrogen interactions with different hydrogen traps in ferritic FeCr alloys with different chromium contents, dislocation densities, and grain sizes. In addition, we confirm the validity of a novel nanohardness-based diffusion coefficient approach by performing in situ nanoindentation testing. Simultaneous acquisition of the dynamic time-resolved mechanical response of FeCr alloys to hydrogen and the hydrogen diffusivities in these alloys is possible during continuous hydrogen supply. Dislocations, grain boundaries and Cr atoms induce reversible hydrogen trapping sites in these ferritic alloys, leading to the reduction of the hydrogen diffusion coefficients and the increase of the absorbed hydrogen.

cond-mat.mtrl-sci