Using copper foil, glass containers and a common household microwave oven, University of Wyoming researchers turned carbon powder into more valuable nanographite.
The discovery is another step forward in the search for alternative uses for coal, at a time when demand for it is declining due to fears about climate change.
In the new work, the researchers claim they created a microwave oven environment to successfully convert untreated carbon powder into nanographite, which is used as a lubricant and in products ranging from fire extinguishers to lithium-ion batteries.
This “one-step metal microwave” represents a novel approach that can be a simple and relatively inexpensive coal conversion technology.
Early research has shown that microwaves can be used to reduce moisture in coal and remove sulfur and other minerals. However, most of these methods require special chemical pre-treatment of the coal.
In their experiment, the researchers simply ground the raw coal. Then the powder was placed on copper foil and sealed in glass containers with a gas mixture of argon and hydrogen. An ordinary microwave was chosen for the experiment: it is more convenient and can provide the desired level of radiation.
The sparks generated by microwaves generated the high temperatures required to convert the carbon powder into polycrystalline graphite. The researchers argue that the new method of converting coal could be improved and implemented on a larger scale to produce both higher quality and quantity of nanographite materials.