Graphene -- which is capable of outperforming steel and Kevlar in bulletproof vests, and has uses in solar cells, electrical circuits and medicine -- has been manufactured from several materials including plastic, cockroaches, Girl Scout cookies and dog feces. While it can be grown from any source of carbon, the challenge has been to find one that is reasonably cheap, sustainable and scalable.
A team of scientists from James Cook University in Queensland, Australia, and collaborators from institutions in Australia, Singapore, Japan and the U.S. found that graphene can be grown from the tea tree plant Melaleuca alternifolia, which is also used to make essential oils for traditional medicine, according to reports Friday.
The researchers also found that they could manufacture a significant amount of almost defect-free graphene in a matter of seconds to minutes, while current methods usually take several hours. Also, unlike current methods, the new technique works at relatively low temperatures, without the need for catalysis or non-renewable, toxic or explosive precursors. The results of their research were published in the journal Nano Letters.
"This research realizes fabrication of good-quality, few-layer graphene from an environmentally friendly precursor," lead author Mohan Jacob of James Cook University told Phys.org. "Overall, large-area graphene fabrication using a fast, environmentally friendly precursor and process at a relatively low fabrication temperature is the major significance of this work."
The team used a technique called plasma-enhanced chemical vapor deposition, which involves feeding the vaporized tea tree extract into a heated tube, and then into an activated plasma electrode, which almost instantly transformed the vapor into graphene film.
The researchers said that the graphene films produced from this method could have applications in advanced memory devices known as memristors, which store memory based on their level of electrical resistance. They created a memristor device by sandwiching a semiconductor between graphene and aluminum.
"We will be focusing on optimizing the material properties and implementing the material in various electronics applications," Jacob said.