Synthesis of submicrometre Cu particles via a reduction in triethanolamine solvent

Abstract

With the aim of preparing a low-cost filler material to enhance the bondability of a sinter-bonding paste, submicrometre Cu particles with little agglomeration were successfully synthesised by a simple solvothermal recipe using CuO as a precursor and triethanolamine as a solvent. The required synthesis time and the average size (216-821 nm) of the synthesised Cu particles decreased proportionally with the increasing synthesis temperature. The required synthesis times were found to be 30 and 60 min and the particle sizes of 410 and 821 nm were achieved at synthesis temperatures of 200 and 180°C, respectively. The CuO particles were transformed into Cu 2 O nanoparticles by accepting the hydrogen ions and electrons released during the conversion of the triethanolamine to the aldehyde by the oxidation of its three hydroxyl groups. Submicrometre pure Cu particles could be subsequently formed from aggregates of the Cu 2 O nanoparticles by removing O ions from Cu 2 O during the continuous conversion of the aldehyde to nitrilotriacetic acid.