Synthesis of RuO2 Nanowires by Alkali-Assisted Oxidation of Ruthenium in Plasma Afterglow at Atmospheric Pressure

Abstract

RuO2 nanowires are synthesized by oxidation of ruthenium thanks to a micro-post-discharge at atmospheric pressure. However, RuO2 nanowires form islands. The growth mechanism depending on surface defects, the surface density of the nanowires is limited. We report on the influence of two alkali salts, NaCl and KCl, deposited as grains on ruthenium to act as defects and increase the nanowire density. These grains induce the growth of RuO2 nanowires all around them, creating a circular area where nanowires are found. Nanowires start growing at the triple point at the grain base where the alkali-salt grain, ruthenium from the substrate and oxidizing gaseous species coexist. When nanowires grow, the stress induced in the surrounding layer creates new cracks, making possible the radial propagation of the nanowires. The presence of nanowires on grains is due to the etching mechanism that converts the alkali salt into an oxide, enabling onward oxidation of ruthenium.

Tunable morphologies of ultrathin ZnO nanostructures synthesized by a plasma afterglow-assisted oxidation process and their photocatalytic properties

“…In this work, we propose another strategy to synthesize ultrathin ZnO nanostructures with high growth rates, by using flowing microwave plasma afterglow-assisted oxidation treatments. Plasma afterglowassisted oxidation processes enable the synthesis of a large variety of metallic oxide nanostructures, even at atmospheric pressure [20][21][22]. Indeed, afterglow processes benefit from a higher reactivity of the oxidizing gas phase at moderate temperature compared to thermal heating processes, because of the presence of active oxygen species like oxygen atoms or metastable states of O 2 .…”

Conformal Deposition of RuO2 on Cu via a Galvanic Cementation Reaction

“…The vacuum-based techniques include physical vapor deposition, chemical vapor deposition (CVD), and atomic layer deposition (ALD). [13][14][15][16] In practice, these vacuum-based approaches often entail complicated equipment, costly precursors, slow processing time, and unnecessary material waste. In contrast, the solution-based routes such as sol-gel synthesis, electroless plating, and electrodeposition are known for simple setups, inexpensive precursors, and adaptability to substrates with different form factors.…”