Fullerene crystals with bimodal pore architectures

A research group headed by MANA Scientist Dr. Lok Kumar Shrestha of the Supermolecules Unit, for the first time demonstrated template-free novel mesoporous carbon material: fullerene (C₆₀) crystals with bimodal pore architectures and having highly crystallized framework. Experiments have proven that this novel meso- and macroporous material show better electrochemical performance compared to pristine C₆₀ due to higher electrochemically active surface areas.

In this research, novel fullerene (C₆₀) crystals with bimodal mesoporous and macroporous structures composed of a highly crystallized framework has prepared by using a liquid-liquid interfacial precipitation (LLIP) method involving the interface between isopropyl alcohol (IPA) and a saturated solution of C₆₀ in a mixture of benzene and carbon tetrachloride (CCl₄). The resulting mesoporous C₆₀ exhibits two-dimensional (2D) hexagonal plate morphology.

Porosity and electrochemically active surface area could be flexibly controlled by increasing the mixing fraction of CCl₄ and benzene. The synergistic effect of mixing solvents (CCl₄ and benzene) is mainly responsible for the formation of such porous structure. Otherwise, in an individual IPA/CCl₄ and IPA/benzene system, 2D plate like and 1D nanowhiskers morphology without pores are observed. In solution-based crystallization (LLIP method), solvent molecule gets entrapped during crystallization, which upon slow release/or evaporation creates a porous structure. It is expected that this methodological innovation will be a milestone for the production of highly crystalline carbon-based materials offering better performance in catalytic, electrochemical, and sensing properties.

These research results are recently published in Journal of American Chemical Society, 2013, 135, 586-589.