Historic Carbon Filaments Show Evidence of Turbostratic Graphene

Professor James Tour and his research group at Rice University have revisited one of the most familiar devices in modern history, Thomas Edison’s 1879 incandescent light bulb, and found evidence that its carbon filament may have briefly produced a graphene-like material. In a recent study published in ACS Nano, the team reports that rapid electrical heating of carbon filaments under Edison-style conditions can generate turbostratic graphene, a layered form of carbon with properties similar to graphene.

Eddy, L., Choi, C. H., Sharp, J., Kittrell, C., Han, Y., & Tour, J. M. (2026). Evidence for Graphene Formation in Thomas Edison’s 1879 Carbon Filament Experiments. ACS Nano, 20(2), 1769–1774. https://doi.org/10.1021/acsnano.5c12759

Professor James Tour and his research group at Rice University stated,

“You can’t fool a chemist. But I finally found a small art store in New York City selling artisan Edison-style light bulbs.”

The idea emerged from ongoing efforts in the Tour laboratory to develop scalable methods for producing graphene from inexpensive feedstocks. Graphene, a single atomic layer of carbon arranged in a hexagonal lattice, has been widely studied since its isolation in 2004. Its mechanical strength, electrical conductivity and transparency have made it central to research in electronics, energy storage and advanced composites.

In recent years, Tour’s group has explored a method known as flash Joule heating, in which a brief, high-current pulse rapidly heats carbon materials to temperatures above 2,000 degrees Celsius. Under these extreme but short-lived conditions, disordered carbon can reorganize into graphene-like structures. The process occurs in milliseconds and does not require complex reactors.

While considering the minimal equipment needed to achieve flash Joule heating, Lucas Eddy, first author on the study and a former graduate student in the lab, noted that Edison’s early carbon filament bulbs created similar thermal conditions. When current passes through a resistive carbon filament, it heats rapidly to temperatures that approach or exceed 2,000 degrees Celsius. Although Edison’s goal was illumination, not materials synthesis, the physical conditions inside the bulb overlap with those used in modern graphene production.

To test the idea, the Rice team reconstructed a system modeled closely on Edison’s original patent specifications. They sourced artisan light bulbs that used carbonized bamboo filaments rather than modern tungsten. The filament diameters and overall configuration closely resembled late nineteenth-century designs. The bulbs were powered using a direct current source comparable in voltage to Edison’s early setups.

The experiment was intentionally brief. Each filament was energized for approximately 20 seconds, a duration chosen to reach high temperatures without prolonged heating that might favor graphite formation. After the heating cycle, the filaments displayed a visible change in appearance, shifting from a matte dark surface to a more reflective metallic sheen.

To determine whether structural transformation had occurred, the team employed Raman spectroscopy, a technique commonly used to characterize carbon materials. Raman spectra can distinguish between amorphous carbon, graphite and graphene-based structures by analyzing vibrational modes of the carbon lattice. The results indicated the presence of turbostratic graphene within portions of the filament.

Turbostratic graphene differs from perfectly stacked graphite. In this form, graphene layers are misaligned relative to one another, reducing interlayer coupling and preserving some properties associated with isolated graphene sheets. This structure is consistent with rapid thermal processing, where carbon atoms reorganize under extreme temperatures and then cool before long-range graphite order can develop.

The findings do not prove that Edison intentionally created graphene, nor can they confirm that such structures persisted during the original 13-hour illumination tests reported in the late 1800s. Prolonged heating would likely have driven the material toward more stable graphite. However, the Rice study demonstrates that the transient conditions in carbon filament bulbs were sufficient to produce graphene-like carbon at least momentarily.

The work highlights how historical technologies can intersect with modern materials science. Edison’s experiments predated theoretical predictions of graphene by decades and its experimental isolation by more than a century. Yet the physical principle underlying flash Joule heating, rapid resistive heating of carbon, was already present in early electrical engineering.

The study also underscores the value of reexamining established systems with contemporary analytical tools. Techniques such as high-resolution Raman spectroscopy and electron microscopy allow researchers to detect structural features that would have been inaccessible in the nineteenth century. What appeared to be a simple incandescent filament can now be probed at the nanoscale.

From an engineering perspective, the results reinforce the practicality of rapid thermal methods for graphene synthesis. Flash Joule heating has already been explored for converting waste carbon sources into graphene-like materials. Demonstrating that a basic light bulb configuration can achieve comparable temperatures suggests that scalable production may not require complex infrastructure.

The research connects historical experimentation with current efforts to optimize two-dimensional materials. While graphene is often described as a product of twenty-first-century nanotechnology, its fundamental formation conditions are rooted in classical electrical heating. Revisiting those conditions with modern insight provides both a technical perspective and a reminder that overlooked material transformations may be embedded in legacy technologies.

The Rice team’s findings do not alter the established timeline of graphene’s discovery. Instead, they suggest that materials with graphene-like structure could have formed unintentionally long before they were understood. For scientists and engineers, the broader lesson is that revisiting familiar systems through the lens of modern characterization can reveal unexpected pathways to advanced materials.

As research into scalable carbon processing continues, the intersection of historical devices and contemporary nanoscience offers a useful reminder that innovation often builds on principles already present in earlier technologies.