Rice University team creates 3D objects from graphene foam

Rice University scientists have developed a simple way to create conductive, 3D objects made of graphene foam. The resulting objects may offer new possibilities for energy storage and flexible electronic sensor applications, according to Rice chemist Prof. James Tour.

Rice team creates 3D objects from graphene foam image

The technique is an extension of groundbreaking work by the Tour lab that produced the first laser-induced graphene (LIG) in 2014 by heating inexpensive polyimide plastic sheets with a laser. The laser burns halfway through the plastic and turns the top into graphene that remains attached to the bottom half. LIG can be made in macroscale patterns at room temperature.

Rice team created graphene pellets using a simple, scalable process

Researchers at Rice University have demonstrated the mechano-chemical assembly of functionalized graphene layers into 3D graphitic solids (“graphite pellets”) via room temperature and low energy consuming processing. The pellet material is reportedly stronger and lighter than commercial graphite electrodes and could be promising for electrical storage applications with high energy and power densities.

Rice graphene pellets process image

The environmentally friendly, scalable process can be done in minutes by hand by grinding chemically modified graphene into a powder and using a hand-powered press to squeeze the powder into a solid pellet. The team demonstrated how to make a battery-sized pellet, but the graphene powders with chemical functionalities attached to it can be pressed into any form. They said the material could be suitable for structural, catalytic, electrochemical and electronic applications.

Rice University team detects metal in ‘metal-free’ graphene catalysts

Rice University scientists, led by Prof. James Tour, along with teams from the University of Texas at San Antonio and the Chinese Academy of Sciences, Beijing, China have detected a deception in graphene catalysts that, until now, gone unnoticed. Graphene has been widely tested as a replacement for expensive platinum in applications like fuel cells, where the material catalyzes the oxygen reduction reaction (ORR) essential to turn chemical energy into electrical energy.

Rice team finds  manganese atoms in graphene catalysts image

Since graphene isn't naturally metallic, researchers have been baffled by its catalytic activity when used as a cathode. The Rice team has now discovered that trace quantities of manganese contamination from graphite precursors or reactants hide in the graphene lattice. Under the right conditions, those metal bits activate the ORR. Tour said they also provide insight into how ultrathin catalysts like graphene can be improved.

Rice University team patterns graphene onto food, paper, cloth, cardboard

Scientists at Rice University have enhanced their formerly invented LIG technique to produce what may become a new class of edible electronics. The Rice lab of Prof. James Tour is investigating ways to write graphene patterns onto food and other materials to embed conductive identification tags and sensors into the products themselves.

Rice lab's graphene on toast image

"This is not ink," Tour said. "This is taking the material itself and converting it into graphene". The process is an extension of the Tour lab's perception that anything with adequate carbon content can be turned into graphene. In recent years, the lab has developed and expanded upon its method to make graphene foam by using a commercial laser to transform the top layer of an inexpensive polymer film.

Graphene to potentially replace platinum for cheaper fuel cells

Researchers from Rice University have discovered that nitrogen-doped carbon nanotubes or modified graphene nanoribbons could potentially replace platinum, one of the most expensive facets in fuel cells, for performing fast oxygen reduction—a crucial reaction that transforms chemical energy into electricity.

Graphene to replace platinum in fuel cells image

The researchers used computer simulations to see how carbon nanomaterials can be improved for fuel-cell cathodes and discovered the atom-level mechanisms by which doped nanomaterials catalyze oxygen reduction reactions. The simulations also revealed why graphene nanoribbons and carbon nanotubes modified with nitrogen and/or boron are so sluggish and how they can be improved.

Versarien - Think you know graphene? Think again!Versarien - Think you know graphene? Think again!