Molecular-assembly of graphitic carbon nanomaterials via biomimetism and their applications

Abstract

Naturally occurring biomineralization has become one of the key process in the search for highly functional, nano-architectured materials. This is due to its environmentally benign process; low cost, rapid mineral deposition with low energy consumption. Moreover, the structures of biominerals can be controlled from the nanometer to macroscopic scale, resulting in sophisticated architectures that provide desired multifunctional properties. For the reason, recently, there are many efforts to understand mechanism of biomineralization and integrate into nano-composite materials. In this study, we report an efficient and environmentally benign biomimetic mineralization at graphitic carbon (carbon nanotubes and graphene) surface, which successfully created an ideal biomineral/carbon hybrid structure without any harsh surface treatment or interfacial adhesive layer. The N-doped sites at graphitic carbon nanomaterials successfully nucleated the high yield biomimetic deposition of uniform-thick biomineral nanoshell in the neutral pH aqueous media at ambient pressure and temperature and generated in ‘N-doped carbon/biomineral hybrid’. Unlike previously known organic biomineralization templates, such as protein or peptides, the electro-conductive and high temperature stable graphitic carbon plane enabled high temperature thermal treatment and corresponding crystal structure transformation of biomineral for optimized material properties. The direct contract of graphitic carbon surface and biomineral shell without any adhesive interlayer introduced new carbon energy level in the bandgap and thereby effectively tuned the bandgap energy and electronic structure. Consequently, the created graphitic carbon/biomineral hybrid showed a greatly enhanced catalytic efficiency and controlled wettability with dual stimuli. By utilizing this novel phenomena, we also showed an efficient, spontaneous process and materials for various applications, such as, counter electrode for dye-sensi...