High-load Mg2Ni nanoparticle-carbon nanofiber composites for hydrogen storage

• Published in: Nanoscale 2024-10, Vol.16 (38), p.17908-17925
• Main Authors: Ruiz-Santacruz, Eduardo David, de Jesús Vega-Soria, José, Cruz-Jiménez, Aura Karina, Caudillo-Flores, Uriel, Torres-García, Nidia Libia, Suárez-Alcántara, Karina
• Format: Article
• Language: English
• Subjects: Ball milling; Carbon fibers; Composite materials; Composition; Hexanes; Hydrogen; Hydrogen storage; Magnesium; Nanofibers; Nanoparticles
• ISSN: 2040-3364; 2040-3372; 2040-3372
• DOI: 10.1039/d4nr01725k

Herein, a simple synthesis method for Mg2Ni composites with carbon nanofibers capable of hydrogen storage is presented. Specifically, n-butyl-sec-butyl-magnesium solution in hexane (C8H18Mg, 0.7 M) and bis-cyclopentadienyl nickel(ii) (nickelocene or NiCp2) were used as precursors for the Mg2Ni nanoparticles. Subsequently, the nanoparticles were composited with carbon nanofibers (CNF) with high loading of Mg2Ni of 50 wt%, 75 wt%, 90 wt%, and 100 wt%. The physicochemical characterization of the materials indicated that the size of the as-prepared Mg2Ni nanoparticles was less than 5 nm and they were highly agglomerated due to a carbon-based binder. The best hydrogen storage values were determined to be 2.6–2.7 wt%. Among the tested materials, the composite with 75 wt% of Mg2Ni in CNF presented the best hydrogen uptake. The pressure–composition–temperature curves indicated changes in the hydriding equilibrium pressures of the Mg2Ni nanoparticles compared to the material with a similar composition produced using ball-milling and thermodynamic calculations. Thus, the results presented herein indicate the beneficial effect of nanosizing on hydriding reactions.