Over the past few years, the Rice University researchers responsible for developing a graphene de-icing coat for plane wings. Now, the team managed to make graphene out of wood, by blasting a piece of pine with a laser beam.
laser induced graphene
Normally graphene takes on a two-dimensional form, as a sheet of carbon just one atom thick. But it’s not the most practical material to work with in that structure. So, in 2014 researchers make a 3D graphene foam by heating a polymer surface with a laser. They called the result laser-induced graphene (LIG) and found other uses for it.
LIG made by using a specific plastic called polyimide. But, the researchers found that some types of wood have a similar mechanical structure with an organic polymer called lignin. Lignin is the complex organic polymer that forms rigid cell walls in wood.
For some applications, such as 3D printed graphene, polyimide may not be an ideal substrate, says, Ruquan Ye, lead researcher on the study. In addition, wood is abundant and renewable.
To make the graphene foam, the team heated a piece of pine with an industrial laser, at room temperature and pressure in an inert argon or hydrogen atmosphere. The absence of oxygen is important, allowing the wood to be modified without burning.
The team found that changing the intensity of the laser altered the chemical composition and thermal properties of the LIG. 70 percent power was the optimal amount to produce the high-quality graphene, which was dubbed pine laser-induced graphene (P-LIG).
The researchers then tested how well their new material could conduct electricity. They made electrodes by depositing layers of cobalt and phosphorus, or nickel and iron on top of the P-LIG, to make a pair of electro catalyst for splitting water into hydrogen and oxygen.
Depositing polyaniline onto P-LIG instead made it a practical supercapacitor for storing energy. Down the track, the team believes wooden electronics could help curb the growing e-waste problem.
More information: [Advanced Materials]