Wedoany.com Report on Feb 25th, Researchers at the University of New South Wales have developed a new method for producing high-quality graphene using discarded peanut shells. This process is expected to reduce the production cost of graphene and promote the high-value conversion of agricultural waste.
Professor Yao-Hua Guan, the team leader, stated: "Graphene is one of the thinnest, strongest, and most conductive materials known. It consists of a single layer of carbon atoms arranged in a hexagonal lattice, with strength far exceeding that of steel, electrical and thermal conductivity superior to copper, and it is almost completely transparent." These properties make graphene widely applicable in fields such as batteries and solar panels. However, its large-scale production typically relies on chemical and energy-intensive methods, resulting in high costs.
Professor Guan pointed out: "Approximately 55 million tons of peanuts are produced globally each year, with most shell waste being discarded or used for low-value purposes. Our research demonstrates that peanut shells can be converted into high-quality graphene with significantly lower energy consumption than existing methods and without the need for chemicals, offering environmental benefits." Graphene can be used to create lighter, stronger, and more conductive materials for applications in electronics, energy storage devices, medical equipment, and wearable technology.
The key to the research lies in peanut shells' rich lignin content, a natural polymer with high carbon content. The team first grinds the shells and heats them to about 500°C for five minutes to remove impurities, converting them into carbon-rich char material. Then, through flash Joule heating, the temperature is raised to about 3000°C within milliseconds, causing the carbon atoms to rearrange and form a single layer of graphene. Traditional methods often use carbon black derived from fossil fuels, whereas the new process uses only char derived from peanut shells, making it more environmentally friendly and simplifying the procedure. The entire process takes about 10 minutes, with significantly reduced energy consumption.
Currently, the new process produces a limited quantity of graphene, but researchers anticipate commercialization within three to four years. Professor Guan added: "Lignin is present in various plants. We plan to test other organic waste materials such as coffee grounds and banana peels. This work demonstrates a balance between energy efficiency, graphene quality, and economic feasibility, highlighting the potential for large-scale conversion of biomass into graphene."
