Graphyne, retractions, and bad blood between chemists

Valentin Rodionov, an organic chemist at Case Western Reserve University, recently rejected a paper he was peer-reviewing. This review was not his first encounter with the study. It had already caused him a lot of heartache.

An earlier version of the study, published by Nature Synthesis in 2022, had scooped Rodionov and his team in describing the synthesis of γ-graphyne—a new form of carbon with triple bonds. The paper prompted funding agencies to question whether to continue backing him. A postdoctoral researcher whose work in Rodionov’s lab was dependent on the funding had to temporarily leave the US.

At first glance, Rodionov says, the 2022 study’s method looked plausible, but the data didn’t sit right with him. Not only did the results disagree with what his own group had observed, they seemed to suggest that the carbon atoms in the lattice were smaller than physically expected. He reported his concerns to the journal, alleging data fabrication, and posted about them on the online platform PubPeer, where scientists often discuss papers.

In September 2024, the authors of the Nature Synthesis paper retracted it, noting that an investigation had found that data used to produce one supplementary figure had been fabricated and that processes used to produce another figure “deviated from standard practices.” That investigation had been conducted by the Office of Research Integrity at the University of Colorado Boulder (UC), where the research was carried out. Although the probe concluded that the fabrication didn’t affect the major claims of the paper, the authors retracted it anyway.

Graphyne research remains a hot topic: theorists have proposed that graphyne could prove important for a range of electronic, mechanical, and optical applications. Some say it might be a better material for certain electronic devices than graphene—the discovery of which garnered two scientists the 2010 Nobel Prize in Physics.

But with this and other graphyne-related papers being retracted and many more being questioned, some scientists are asking whether constructive criticism and healthy debate is devolving into mudslinging. And at least one former researcher in the field questions whether anyone has successfully synthesized γ-graphyne at all.

Checkered history for a graphyne paper

Wei Zhang, the organic chemist at UC who coauthored the original paper, and some of his colleagues continue to try to publish an updated version of their 2022 paper. Small Methods, the journal where they submitted the new version, has rejected it. In an interview, Zhang says that although two referees provided positive reviews, one gave a negative one.

That critical reviewer was Rodionov, who had previously penned a critical Matters Arising article for Nature Synthesis about Zhang and his team’s synthesis. “For them, it was probably a nightmare scenario,” Rodionov says, given his involvement in prompting the original retraction.

Rodionov says he wrote a personal note to the editor of Small Methods explaining that a previous version of the study had been retracted. When asked why the journal rejected the paper, the journal’s editor in chief, Xi Wen, tells C&EN that the information is confidential.

Rodionov says he rejected the revised study because it essentially contains the “the same data, same paper, same text, same images,” minus the data that was proven to be fabricated. A few months after rejecting it, Rodionov says, he received a request to referee the same paper from a different editor at Small Methods. Later, the journal rejected the paper again, Rodionov notes.

Zhang notes that, after the first rejection, he and his colleagues resubmitted the study along with a 22-page letter addressing the critical reviewers’ questions and a rebuttal. “The reviewer commented ‘The authors have failed to address even a single substantive point raised in my original review,’ which is absolutely not true,” he says.

In addition, Zhang disputes that the new paper is the same as the last one, noting that his new collaborators have validated the structure of γ-graphyne from multiple samples his group sent them.

Ramón Torres Cavanillas, an inorganic chemist at the University of Valencia, is one of those collaborators. He is a coauthor of the paper considered by Small Methods but was not listed on the retracted paper. “The synthesis of these compounds is extremely complicated,” Cavanillas says.

While Cavanillas was at the University of Oxford, he says, Zhang and colleagues mailed several samples of up to 20 mg of γ-graphyne to him to split from multilayer compounds to single-layer ones and to observe using advanced electron microscopy.

After he conducted various spectroscopy experiments, Cavanillas says, he could “directly visualize the formation of a superstructure that was in good agreement with what is expected for γ-graphyne.”

Cavanillas says he disagrees with Rodionov’s suspicions about the synthetic method used by Zhang and his colleagues. “If I have any suspicion that the compound is not real, I wouldn’t put my name on the new version of the paper,” he says.

Zhang acknowledges problems with the paper that Nature Synthesis published. “Following publication, irregularities were discovered in a subset of powder X-ray diffraction data processed by a former student,” he tells C&EN in an email. “Although an institutional investigation concluded that these issues did not affect the paper’s major conclusions, the authors retracted the article to uphold the highest standards of scientific integrity.”

Nicole Mueksch, director of issues management and spokesperson at UC, declines to name the student responsible for the fabricated data, citing legal reasons. The new version of Zhang’s study, seen by C&EN, lists all the coauthors of the Nature Synthesis paper, along with nine new authors. An interview request sent to the UC email address of Rui Lyu—the only coauthor affiliated with UC who didn’t reply to the Nature Synthesis editors’ correspondence about the retraction—bounced.

Multiple probes into allegations

Rodionov’s complaint to UC, letter to Nature Synthesis, and posts on PubPeer set off a chain reaction of investigations.

In May 2023, Jon Reuter, UC’s research integrity officer, wrote to Rodionov (PDF) informing him that the institution’s standing committee on research misconduct (SCRM) voted to accept the recommendations of the inquiry committee that was appointed to explore the allegations of research misconduct he had made in his complaint.

Then, in February 2024, Tom Heddleston, UC’s research compliance associate, contacted Rodionov (PDF), explaining that the institution’s provost had reviewed the SCRM’s investigation report and accepted its findings. That investigation found that one of the authors of the Nature Synthesis paper “had fabricated the data that Supplementary Figure S10 was based on, and that the procedure used to produce Figure 2b deviated from standard practice and was not adequately reported.”

Supplementary figure S10 shows the X-ray diffraction spectra of γ-graphyne before and after treatment with boiling water, hydrochloric acid, and sodium hydroxide; figure 2b shows various wide-angle X-ray scattering patterns.

In his letter, Heddleston said Zhang and colleagues were now required to contact Nature Synthesis and inform them of the fabricated data used to produce supplementary figure S10 and issue an erratum that explains the procedures used to create figure 2b. “The Investigation also found that the issues with Figure S10 did not threaten the central findings of the paper (the synthesis of γ-graphyne),” Heddleston wrote.

If Rodionov wished to see a redacted version of the investigation report, Heddleston wrote, he would first need to sign a confidentiality agreement. Rodionov didn’t sign it. “I have no idea how to distribute the blame here,” Rodionov says. “It’s up to the university to do this.”

Cavanillas says he noticed in his experiments in 2023—when his lab group started collaborating with Zhang and colleagues—that the X-ray diffraction pattern was not the same as the one reported in supplementary figure S10. He adds that he discussed the discrepancy with his UC collaborators but wasn’t aware that the data underlying the figure had been fabricated. Had he known the Nature Synthesis paper would later be pulled, Cavanillas says, he would have reconsidered the collaboration.

Alexandra Groves, chief editor of Nature Synthesis, which is published by Springer Nature, tells C&EN by email that, after UC’s probe, Springer Nature’s research integrity group conducted its own investigation and concluded that retraction was the most appropriate course of action “as we no longer had confidence in the paper as published.”

“After this decision was communicated to the authors, they chose to proceed with an author-led retraction,” Groves writes. “As a journal, our responsibility is to safeguard the integrity of the published scholarly record. Our decision reflects our independent editorial judgement that retraction was the best way to ensure this.”

Michael Haley, a synthetic organic chemist at the University of Oregon, was one of the peer reviewers of Zhang’s original study and wrote a corresponding News and Views article about it for Nature Synthesis—which was retracted at the same time as the study.

In an interview, Haley says he thought a correction would have been sufficient to fix the problems with the paper. “I feel much more badly for Zhang than I ever would for me,” he adds, calling the retraction of his highlight article “no big deal.”

Zhang argues that the retraction of the 2022 study is dissuading editors from publishing the updated manuscript. “It could be more fair and more objective,” he says, referring to the peer-review process. Cavanillas says he understands why journals are hesitant to publish the paper. “A retraction is something pretty serious,” he says.

Cavanillas says he doesn’t see any way of getting the paper published in a peer-reviewed journal without going through Rodionov. “No matter where we send it, we’re going to end up with Rodionov as a reviewer,” he says.

Haley says he has seen many cases over the years of direct academic rivals refereeing each other’s work. Not only can such reviewing allow personal sentiments and biases to sneak into the process, it can lead to one team beating another to publication. “Preventing scooping is impossible,” Haley says. “It just depends on if something is a hot area or not.”

Zhang has a patent pending for the method he developed for synthesizing γ-graphyne and says his group has also successfully synthesized β-graphyne, another form of carbon, using a similar approach. That work will be submitted to a journal soon, he notes, with the aim of publishing it alongside the new version of the γ-graphyne paper. Zhang says he and his colleagues also filed an invention disclosure for their β-graphyne synthesis this week.

Zhang and Cavanillas contend that graphyne can be synthesized in multiple ways. But experiments for synthesizing and authenticating carbon forms such as graphyne are expensive, requiring access to beamlines and high-level electron microscopy. “We had trouble securing funding ourselves,” Rodionov says, noting that he had to spend several months convincing a program officer at the US Department of Energy to fund his work and explaining why other research in the area was not credible.

“We had a similar conversation with another program officer who basically told me outright that ‘you have to prove to me that I have to fund you versus them,’ ” Rodionov recalls. He also notes that publication of his papers was slowed when peer reviewers asked him why he wasn’t citing the Nature Synthesis paper, which hadn’t been retracted at the time.

Graphyne: Equal parts hope and hype

In the 1960s, scientists from the Soviet Union claimed to have developed carbyne, which they contended was the most stable form of carbon. At the time, the US Central Intelligence Agency was also tracking the development of what some scientists were touting as a wonder material.

But it turned out that carbyne didn’t exist—at least not in large quantities. “You could not make more than about 20 of those units, because then it polymerizes quite explosively,” Rodionov notes. Fast-forward to 1987, when chemist and nanoscientist Ray Baughman and colleagues predicted that another strong but more stable form of carbon, graphyne, could be created synthetically. (Baughman died last September.)

Graphyne—specifically γ-graphyne, thought to be its most thermodynamically stable lattice—is significant because researchers such as Rodionov think it could fulfill the potential graphene once seemed to offer. In 2010, when the Nobel Prize in Physics was awarded for graphene research, many thought graphene would be a “magic material” that would replace silicon in electronics, Rodionov says. It was supposed to be “smaller, faster, and better than anything you can do with silicon,” he recalls.

But graphene doesn’t have a band gap—the energy gap in some solids that allows them to function as semiconductors. In contrast, graphyne has a sizable band gap, according to a 2022 study coauthored by Baughman, Rodionov, and others.

Elements that exist in multiple forms are called allotropes. The two most common carbon allotropes are diamond and graphite (which is made up of graphene building blocks). “A new carbon allotrope is a big deal,” Rodionov says, noting that graphite has a number of commercial applications, including nuclear materials, water purification, and batteries.

But to try graphyne in new applications, chemists would need to synthesize it in large enough quantities for testing.

Haley says he has read both Rodionov’s and Zhang’s work on synthesizing γ-graphyne and is convinced that Zhang’s method has more validity. Cavanillas, however, says Rodionov’s synthesis is also valid. “I have no reasons to doubt it,” he says, adding that he is considering trying to reproduce it independently.

In 2005, Haley decided to pull the plug on his graphyne research, describing it as “the total synthesis of an unnatural product.” Synthesizing graphyne would take a lot of steps, he says. “You start off with 50 g of a precursor, and if you were lucky, you had 5 or 10 mg of what you wanted in the end,” Haley explains. “It just got to a point where the reward was not commensurate with the effort.”

Haley continued to read and review papers associated with graphyne research but recently decided to end those efforts too. “Proof means definitive structural evidence,” he says. “I personally have serious doubts that anybody has truly made γ-graphyne.”

Cavanillas thinks both Zhang and Rodionov have the compound—in one form or another. “But it’s not like we have two good options, and one is better than the other,” he says. “Both are bad, and we just have one slightly worse than the other.”

Haley also remains unconvinced of what graphyne research has to offer—at least until someone manages to synthesize enough of it. He cites the example of buckminsterfullerene, a molecule made up of 60 carbon atoms bonded together into a soccer ball shape. “C-60 buckyballs were an anomaly in a mass spectrometry reading until somebody figured out how to make grams upon grams of the stuff,” he notes. “I think that is the rate-determining step.”

Constructive criticism or excessive mudslinging?

Rodionov has raised concerns about other graphyne-related papers. For instance, Sungkyunkwan University chemist Hyoyoung Lee and colleagues published a 2022 study in the journal Matter describing another carbon allotrope, dubbed holey graphyne. When Rodionov raised issues about it to the journal, the editor asked him to submit a rebuttal. Rodionov and colleagues published their failed replication of the paper in Matter in March 2024.

In May 2026, Matter retracted the original holey graphyne paper, noting in the retraction notice that the journal had contacted the authors for their thoughts on the concerns raised and that the “explanation provided regarding synthesis was unsatisfactory in resolving the concerns.”

“I am still very upset,” Lee says in an email. He forwarded C&EN correspondence he had with Matter, the journal’s reply, and a comment article co-authored by Lee and his colleagues that responded to the rebuttal by Rodionov and colleagues.

In an email dated Nov. 11, 2025, to journal officials, Lee wrote that he couldn’t accept their decision to retract his paper solely based on input from Rodionov, “who did not follow our exact conditions.”

In response, Steve Cranford, editor in chief of Matter, wrote that the journal had consulted multiple experts, editorial colleagues, and an internal ethics team before reaching its decision. “The authors were given ample opportunity to respond, which were taken into consideration,” he noted. “There are no claims or accusations of unethical behavior towards any of the authors.”

Rodionov and colleagues are questioning yet other papers in the field. Indeed, Rodionov describes himself as a scientific sleuth who hunts questionable data, analyses, and practices within his field.

In the last few years, multiple tools have surfaced aiming to combat scientific fraud, a problem that has been exacerbated with the rise of generative artificial intelligence. Rodionov recently launched his own for-profit company, Intellicat, in beta to tackle scientific fraud. Large AI companies are trialing his tool, he says.

Asked if he holds a grudge against Zhang and colleagues, Rodionov says, “I do hold a grudge against everybody who is fabricating data.” He says his critiques are not personal but for the betterment of science.

Haley, for one, says he’s sick of mudslinging in this area of research, which is one reason he declined to peer-review the new version of Zhang’s paper. “There’s so much finger-pointing,” he notes. “It’s devolved into a bitter shouting match, and I don’t think anybody’s innocent in this.”

But Cavanillas says debate comes with the territory. “In my opinion, it’s not a bad thing to have some controversy as long as it’s not personal,” he says. “We are doing really high-level science, and there is a risk sometimes of being wrong, and I honestly think there is nothing wrong with that.”

Dalmeet Singh Chawla is a freelance science journalist based in London.