USU Chemists Unlocking Solution to Contorting Nanomaterials

A recently developed nanomaterial known as triazine-based graphitic carbon nitride or “TGCN” shows tremendous promise for future microelectronic devices. A less expensive and more efficient conductor than silicon, the carbon-based, graphene-type material is eyed for a new generation of semiconductors.

But TGCN sheets have an annoying characteristic: Instead of remaining in a smooth, flat plane, they pucker and buckle. The pesky trait is delaying development of the “wonder material” for practical applications.

“Our research focuses on finding the source of this instability,” says Utah State University chemist Alexander Ivanov. “We’re discovering it stems from a molecular energy phenomenon.”

Ivanov, a doctoral student in USU’s Department of Chemistry and Biochemistry, with USU undergraduate Evan Miller, faculty advisor Alexander Boldyrev, and colleagues from Japan’s Kyoto University, published these findings in the May 2015 online edition of The Journal of Physical Chemistry.

The USU chemists employed a version of the Jahn-Teller Effect to describe why TGCN failed to conform to a strictly two-dimensional shape. Essentially, molecules and ions in certain electron configurations become geometrically distorted.

Using computer modeling and electron microscopy, the Aggies observed electron-vibration coupling at the material’s molecular level that caused repulsion between nitrogen atoms resulting in ripple-like distortions.

“We found that adding beryllium atoms suppresses the vibration and allows the structure to remain level,” Ivanov says.

He praised contributions to the project by Miller, who completed his bachelor’s degree in May 2015. The American Fork, Utah, native is the 2015 recipient of the department’s Harris O. and Eleanor Y. Van Orden Award in Inorganic Chemistry as well as the American Chemical Society Inorganic Chemistry Award. This fall, Miller starts a doctoral program in materials science at Idaho’s Boise State University.

“Evan joined our lab just a year ago and, in that time, he’s not only helped to author a significant paper, but has also gotten up-to-speed in complex chemistry in a very short amount of time,” Ivanov says. “In addition, he taught himself Linux (a computer operating system) and varied lab techniques from scratch.”

Ivanov says the TGCN research opens exciting opportunities for further study.

“It’s a new level of science when you can not only predict chemical reactions and synthesize data, but can also explain why these materials function as they do at the molecular level as well as their particular geometric structure.”

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