Research team presents new non-toxic method to produce high-quality graphene oxide

Researchers at Umeå University in Sweden have discovered a new way to synthesize graphene oxide, which has far fewer defects than materials produced by the most common method. Similarly, good graphene oxide could previously only be synthesized using a rather dangerous method involving extremely toxic fuming nitric acid.

Graphene oxide is often used to produce graphene by removing oxygen. However, if there are holes in graphene oxide, there will also be holes after it is converted to graphene. The quality of graphene oxide is therefore very important.

Alexandr Talyzin and his research group have now solved the puzzle of safely manufacturing good graphene oxide. Their results are published in the journal Carbon.

Graphene is often described as a wonder material due to its flexibility, high mechanical strength and conductivity. But all properties of graphene are affected by defects. Graphene produced from graphene oxide has much worse mechanical properties and conductivity than expected.

Numerous studies have demonstrated that synthesis by the most commonly used method, the Hummers method, always results in a significant number of defects. The much older Brodie method provides almost completely hole-free graphene oxide, but this type of graphene oxide is still not produced by any company and is not commercially available. “It is simply too dangerous and not suitable for industrial manufacturing,” says Alexander Talyzin.

Now, researchers have found a new method that combines the Hummers method acid (H₂SO₄) and the Brodie method oxidant (potassium chlorate), allowing them to produce graphene oxide with a number of defects as low as Brodie’s, but using a synthesis process as simple as oxidation of Hummers.

“This method should be named after Bartosz Gurzeda, a researcher working in my group… under the name of the Gurzeda method,” explains Alexandr Talyzin.

According to Talyzin, there are many reasons to believe that the Gurzeda method will become as popular as the Hummers method whenever defect-free graphene oxide is needed. This method makes it possible to manufacture graphene by removing oxygen groups or to prepare protective coatings against gases, semi-permeable membranes, sensors and many other possible applications.

Over the past decade, there has also been a lot of interest in the applications of graphene oxide itself. Graphene oxide layered materials are intensively studied for membrane applications with the dream of producing potable water by simply filtering salts from seawater or by creating semi-permeable protective coatings that allow the allows water to pass while keeping dangerous organic pollutants, such as toluene, away.

“We want the research company to try testing this new graphene oxide in its applications and see the difference. Graphene oxide is not a single material; it is a family of materials with rather different properties, we offering endless opportunities for new applications.” said Talyzin.