Embedded Files
Figure: Experimental setup for synthesis of oxide micro- and nanostructures by Joule heating. a) Joule heating setup in absence of an external electric field. Experimental setup for the application of an external electric field during Joule heating. b) Two plate electrodes parallel to the metallic wire. c) Two plate electrodes perpendicular to the metallic wire. Temperature of wire is measured by a pyrometer. [3]
Growth by resistive Joule heating is a fast, simple, and catalyst-free way to create thin metal oxides from metal wires. It works by heating the wire with an electric current, which causes it to react with oxygen directly from the air.
This process is much faster than traditional methods, with growth occurring in seconds to minutes. This speed is due to two main factors:
Atomic Movement: The electric current and the heat it generates cause metal and oxygen atoms to move quickly.
Steep Temperature Gradients: The heating creates very sharp temperature differences along and across the wire. This is much more intense than what you get with a standard furnace.
During growth, metal ions move outward from the wire, while oxygen ions move inward. This diffusion-driven process creates the final structure. The shape of the resulting metal oxide—wider at the base and narrower at the top—is strong evidence that this ion movement is what controls how the material grows.
Adding an external electric field can further enhance this process. At temperatures below the melting point of the metal, the electric field helps accelerate the movement of metal ions (cations) to the surface of the oxide. This gives you extra control over key features of the resulting oxide nanowires, such as their length, diameter, and density.
Key Capabilities
Key Capabilities
Resistive Joule heating is a simple, one-step method to create oxide materials by heating metal wires in air. By carefully controlling temperature, heating time, electric current, and the type of metal, we can produce various thin metal oxide structures on the wire's surface. The FINE group has successfully used this method to create oxides of molybdenum (Mo), tungsten (W), and nickel (Ni). [1-2,4-5]
For example, applying an external electric field significantly speeds up the growth of α-MoO₃ microplates. This accelerated growth is due to the electric field helping metal ions move faster to the oxide surface, especially when combined with heat. This rapid, non-equilibrium process also allows for the formation of unusual, metastable phases like β-MoO₃ and ε-WO₃, which are not typically found under normal conditions. [3, 4]
Related Publications
Related Publications
[1] Ramos-Ramos, D. J., Vásquez, G. C., & Maestre, D. (2025). Micro-and Nanocrystalline NiO Synthesized by Joule Heating and Thermal Oxidation Methods: A Comparative Study. Crystal Growth & Design. 10.1021/acs.cgd.4c01439
[2] Rodríguez, B., Dolado, J., López-Sánchez, J., Hidalgo, P., & Méndez, B. (2023). Room temperature polymorphism in WO3 produced by resistive heating of W wires. Nanomaterials, 13(5), 884. 10.3390/nano13050884
[3] Piqueras, J., & Hidalgo, P. (2021). Growth of metal oxide nanostructures by thermal oxidation of metals under influence of external electric fields and electric current flow. Physica Status Solidi (a), 218(24), 2100323. 10.1002/pssa.202100323
[4] Rodríguez, B., Hidalgo, P., Piqueras, J., & Méndez, B. (2020). Influence of an external electric field on the rapid synthesis of MoO3 micro-and nanostructures by Joule heating of Mo wires. RSC Advances, 10(20), 11892-11897. 10.1039/d0ra01825b
[5] Mallet, A. F., Cebriano, T., Méndez, B., & Piqueras, J. (2018). Rapid synthesis of undoped and Er doped MoO3 layered plates by resistive heating of molybdenum: structural and optical properties. Physica Status Solidi (a), 215(21), 1800471. 10.1002/pssa.201800471
Page updated
Google Sites
Report abuse