A liquid metal reaction environment for the room-temperature synthesis of atomically thin metal oxides

• Published in: Science (American Association for the Advancement of Science) Vol. 358; no. 6361; pp. 332 - 335
• Main Authors: Zavabeti, Ali, Ou, Jian Zhen, Carey, Benjamin J., Syed, Nitu, Orrell-Trigg, Rebecca, Mayes, Edwin L. H., Xu, Chenglong, Kavehei, Omid, O’Mullane, Anthony P., Kaner, Richard B., Kalantar-zadeh, Kourosh, Daeneke, Torben
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 20-10-2017; The American Association for the Advancement of Science
• Subjects: Aluminum oxide; Chemical synthesis; Crystals; Electronics; Electronics industry; Gadolinium; Gadolinium oxides; Gallium; Gallium oxides; Hafnium; Hafnium oxide; Heavy metals; Liquid metals; Manufacturing Industry; Metal sheets; Metals; Nanomaterials; Nanotechnology; Oxides; Room temperature; Substrates; Thin films
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.aao4249

Two-dimensional (2D) oxides have a wide variety of applications in electronics and other technologies. However, many oxides are not easy to synthesize as 2D materials through conventional methods. We used nontoxic eutectic gallium-based alloys as a reaction solvent and co-alloyed desired metals into the melt. On the basis of thermodynamic considerations, we predicted the composition of the self-limiting interfacial oxide. We isolated the surface oxide as a 2D layer, either on substrates or in suspension. This enabled us to produce extremely thin subnanometer layers of HfO₂, Al₂O₃, and Gd₂O₃. The liquid metal–based reaction route can be used to create 2D materials that were previously inaccessible with preexisting methods. The work introduces room-temperature liquid metals as a reaction environment for the synthesis of oxide nanomaterials with low dimensionality.