RoDSE Electro-Assembling of Iron Quantum Dots on Vulcan Xc-72R for ORR Toward Peroxide Generation for Space Applications

Abstract

Highly dispersed iron-based quantum dots onto powdered Vulcan XC-72R substrate were successfully electrodeposited by the rotating disk slurry (RoDSE) technique. Our findings through chemical physics characterization revealed that the continuous electron pathway interaction between the interface metal-carbon is controlled. The RDE, RRDE, and PGU of in-situ H2O2 generation in fuel cell experiments revealed a high activity for the oxygen reduction reaction (ORR) via two-electron pathway. These results establish the Fe/Vulcan catalyst at a competitive level for space and terrestrial new materials carriers, specifically for the in-situ H2O2 production. Transmission electron microscopy (TEM) analysis reveals the well-dispersed Fe-based quantum dots with a particle size of 4 nm. The structural and chemical-physical characterization through ICP, TEM, STEM, HAADF-STEM, XRD, Raman spectroscopy, XPS, XANES, and EXAFs; reveals that, under atmospheric conditions, our quantum dots system is a Fe2+/3+/Fe3+ combination. The QDs oxidation state tunability was showed by the applied potential. The obtention of H2O2 under the compatibility conditions of the drinking water resources available in the International Space Station (ISS) enhances the applicability of this iron- and carbon-based materials for in-situ H2O2 production in future space scenarios. Terrestrial and space abundance of iron and carbon, combined with its low toxicity and high stability, consolidates this present work to be further extended for the large-scale production of Fe-based nanoparticles for several applications.