Until now, the high cost of graphene production has been the major roadblock in its commercialiZation. Previously, graphene was grown in a highly-controlled environment with explosive compressed gases, requiring long hours of operation at high temperatures and extensive vacuum processing. Australian CSIRO scientists have developed a novel “GraphAir” technology which eliminates the need for such a highly-controlled environment. The technology grows graphene film in ambient air with a natural precursor, making its production faster and simpler.
“This ambient-air process for graphene fabrication is fast, simple, safe, potentially scalable, and integration-friendly,” CSIRO scientist Dr Zhao Jun Han, co-author of the paper published today in Nature Communications said.
“Our unique technology is expected to reduce the cost of graphene production and improve the uptake in new applications.”
GraphAir transforms soybean oil – a renewable, natural material – into graphene films in a single step.
“Our GraphAir technology results in good and transformable graphene properties, comparable to graphene made by conventional methods,” CSIRO scientist and co-author of the study Dr Dong Han Seo said.
With heat, soybean oil breaks down into a range of carbon building units that are essential for the synthesis of graphene.
The team also transformed other types of renewable and even waste oil, such as those leftover from barbecues or cooking, into graphene films.
“We can now recycle waste oils that would have otherwise been discarded and transform them into something useful,” Dr Seo said.
Growing graphene films in the ambient-air process.
The potential applications of graphene include water filtration and purification, renewable energy, sensors, personalised healthcare and medicine, to name a few.
Graphene has excellent electronic, mechanical, thermal and optical properties as well.
Its uses range from improving battery performance in energy devices, to cheaper solar panels.
CSIRO are looking to partner with industry to find new uses for graphene.
Thermal chemical vapour deposition techniques for graphene fabrication, while promising, are thus far limited by resource-consuming and energy-intensive principles. In particular, purified gases and extensive vacuum processing are necessary for creating a highly controlled environment, isolated from ambient air, to enable the growth of graphene films. Here we exploit the ambient-air environment to enable the growth of graphene films, without the need for compressed gases. A renewable natural precursor, soybean oil, is transformed into continuous graphene films, composed of single-to-few layers, in a single step. The enabling parameters for controlled synthesis and tailored properties of the graphene film are discussed, and a mechanism for the ambient-air growth is proposed. Furthermore, the functionality of the graphene is demonstrated through direct utilization as an electrode to realize an effective electrochemical genosensor. Our method is applicable to other types of renewable precursors and may open a new avenue for low-cost synthesis of graphene films.