Graphene, known as the thinnest material discovered to date, consists of a single layer of carbon atoms arranged in a hexagonal pattern. This unique structure endows graphene with a multitude of distinctive properties, making it a promising candidate for various applications, including batteries, super capacitors, antennas, water filters, transistors, solar cells, and touchscreens, among others. The scientists who first successfully synthesized graphene in a laboratory setting were awarded the Nobel Prize in Physics in 2010. However, according to a recent study published in the journal ACS Nano, the iconic 19th-century inventor Thomas Edison might have inadvertently created graphene as a byproduct of his pioneering experiments with incandescent light bulbs more than a hundred years prior.
"Reproducing Thomas Edison's work with the technology and expertise we possess today is incredibly exciting," remarked James Tour, a chemist at Rice University, and a co-author of the paper. "The possibility that Edison could have produced graphene motivates us to explore what other discoveries might be hidden within the annals of historical experiments. What would our scientific predecessors inquire about if they were part of our labs now? What inquiries can we address by reevaluating their work through a contemporary perspective?"
Edison didn't invent the idea of incandescent lamps, as multiple versions existed before his. However, these early lamps typically had a very limited lifespan and needed high electric currents, making them unsuitable for Edison's vision of mass commercialization. He experimented with different filament materials beginning with carbonized cardboard and compressed lampblack, both of which burned out rapidly, as did filaments made from various grasses and canes such as hemp and palmetto. Ultimately, Edison found that carbonized bamboo served as the optimal filament, with life spans exceeding 1200 hours under a 110-volt power source.
Lucas Eddy, a graduate student under Tour at Rice University, sought to develop methods for mass-producing graphene using minimal and cost-effective equipment. He explored possibilities like arc welders and natural events like lightning strikes on treesāboth deemed "complete dead ends." Conversely, Edison's light bulb emerged as an ideal candidate for his studies. Unlike other early light bulbs, Edisonās version achieved the requisite temperatures exceeding 2000 degrees Celsius necessary for flash Joule heatingāthe premier technique for creating so-called turbostratic graphene.