Rice University scientists announced finding a new way to attach organic molecules to graphene, a dense, ultra-strong, two-dimensional carbon sheet, expanding the uses for the "miracle material" into fields of organic chemistry, optics and electronics.
The highly controllable, reversible two-step process developed at Rice chemist James Tour's lab tweaked earlier graphene manipulation techniques and allowed a team of researchers to build patterns in a hydrogenated graphene superlattice that organic chemists can develop into diverse new applications, the university announced about the work detailed in the journal Nature Communications.
Though carbon is key to organic chemical reactions in general, carbon as graphene is inert to many of them, and as a semimetal graphene alone has no band gap, so its usefulness in electronics is limited.
But this project produced a graphene sheet with hydrogen molecules affixed to exact, chosen locations on its basal plane, sites where the chemists then attached organic molecules, the first steps to creating graphene-based organic chemistry, electronics and optics, and new types of metamaterials for nanoengineering more advanced thermoelectric devices and chemical sensors.
Tour explained the significance of the new technique and the wide range of possibilities it has opened:
"(The molecules) would mostly go to the edges, not the interior. But with this two-step technique, we can hydrogenate graphene to make a particular pattern and then attach molecules to where those hydrogens were.
This is useful to make, for example, chemical sensors in which you want peptides, DNA nucleotides or saccharides projected upward in discrete places along a device. The reactivity at those sites is very fast relative to placing molecules just at the edges. Now we get to choose where they go."
Tour Lab/Rice University
Making a superlattice with patterns of hydrogenated graphene is the first step in making the material suitable for organic chemistry. The process was developed in the Rice University lab of chemist James Tour.