Synthesis, characterization, and hydrogen uptake studies of magnesium nanoparticles by solution reduction method

• Simple and convenient method of preparing Mg nanoparticles.
• Characterized by XRD, SEM, FESEM and TEM.
• Trioctylphosphine oxide offers a greater control over the size of the particles.
• Hydrogen uptake of samples at different temperatures and pressure of 4.5 MPa.

Facile and simple, surfactant-mediated solution reduction method was used to synthesize monodisperse magnesium nanoparticles. Little amount of magnesium oxide nanoparticles were also formed due to the presence of TOPO and easy oxidation of magnesium, eventhough, all precautions were taken to avoid oxidation of the sample. Precise size control of particles was achieved by carefully varying the concentration ratio of two different types of surfactants, – trioctylphosphine oxide and hexadecylamine. Recrystallized magnesium nanoparticle samples with and without TOPO were analyzed by X-ray diffraction, scanning electron microscope, field emission scanning electron microscope, and transmission electron microscope. The peak diameters of particles were estimated from size distribution analysis of the morphological data. The particles synthesized in the presence and absence of TOPO found to have diameters 46.5 and 34.8 nm, respectively. This observed dependence of particle size on the presence of TOPO offers a convenient method to control the particle size by simply using appropriate surfactant concentrations. Exceptional enhancement in hydrogen uptake and kinetics in synthesized magnesium nanoparticles as compared to commercial magnesium sample was due to the smaller particle size and improved morphology. Overall hydrogen uptake not affected by the little variation in particle size with and without TOPO.

X-ray diffraction (XRD) pattern of magnesium nanoparticles synthesized by solution reduction method with and without TOPO.Figure optionsDownload as PowerPoint slide