Rapid Synthesis and Correlative Measurements of Electrocatalytic Nickel/Iron Oxide Nanoparticles.

Electrocatalytic core-shell nanoparticles, such as nickel/iron oxides for the oxygen evolution reaction (OER) in alkaline electrolytes, require rapid synthesis and measurement for practical use. To meet this challenge, we investigated a novel process of adding Ni(II) species to Fe nanoparticles immediately after synthesis, which we expected to yield Ni-rich shells around Fe-rich cores. Cyclic voltammetry showed that the overpotential decreased as the molar ratio of Ni to Fe in the synthesis vessel increased from 0.

Nanomaterials for energy conversion and storage.

Nanostructured materials are advantageous in offering huge surface to volume ratios, favorable transport properties, altered physical properties, and confinement effects resulting from the nanoscale dimensions, and have been extensively studied for energy-related applications such as solar cells, catalysts, thermoelectrics, lithium ion batteries, supercapacitors, and hydrogen storage systems. This review focuses on a few select aspects regarding these topics, demonstrating that nanostructured materials benefit these applications by (1) providing a large surface area to boost the electrochemical reaction or molecular adsorption occurring at the solid-liquid or solid-gas interface, (2) generating optical effects to improve optical absorption in solar cells, and (3) giving rise to high crystallinity and/or porous structure to facilitate the electron or ion transport and electrolyte diffusion, so as to ensure the electrochemical process occurs with high efficiency. It is emphasized that, to further enhance the capability of nanostructured materials for energy conversion and storage, new mechanisms and structures are anticipated.