Morphological Control of Cu2O Particles via NaCl Addition and their Antibacterial Activity

• Published in: Korean Journal of Metals and Materials Vol. 63; no. 8; pp. 643 - 650
• Main Authors: Jang, Taejong, Lee, Siwoo, Kim, Yangdo, Ryu, Young Bok
• Format: Journal Article
• Language: English
• Published: 대한금속·재료학회 01.08.2025
• Subjects: 재료공학
• ISSN: 1738-8228; 2288-8241
• DOI: 10.3365/KJMM.2025.63.8.643

Cuprous oxide (Cu2O) particles have attracted significant attention due to their low cost, non-toxicity, and abundance with applications spanning solar energy conversion, photocatalysis, sensing, and antimicrobial fields. The antibacterial activity of Cu2O particles is strongly influenced by their morphology, which determines the exposure of specific crystal facets with distinct surface properties. In this study, the morphological evolution of Cu2O particles was systematically investigated by varying the water content in an ethanol–water mixed solvent and adjusting the NaCl concentration during synthesis. Increasing the water content (0–20 vol%) favored growth along the [100] direction while exposing the (111) facets, resulting in the formation of octahedra. In contrast, the addition of NaCl (Cl:Cu = 1:70–1:40) led to preferential chemisorption of Cl- ions on the (100) planes, inhibiting the growth of these planes and ultimately inducing the formation of cubes. Morphological changes were confirmed by X-ray diffraction and scanning electron microscopy. Antibacterial assays against S. aureus and E. coli at a concentration of 150 µg/mL verified the morphology-dependent antibacterial performance. In particular, octahedral Cu2O particles (Cl:Cu = 1:70) exhibited excellent antibacterial activity with an 88.4% reduction of E. coli. These findings demonstrate that the proposed approach provides a scalable and controllable synthesis strategy for precise morphological control that enables the modulation of exposed crystal planes and enhances the functional performance of Cu2O particles.