Novel Route to Fabericate Graphene Oxide Quantum Dots (GOQDs) and Graphene Quantum Dots (GQDs)

摘要

The unique structure of monolayered graphene composed of a one-atom thick two-dimensional crystal of sp2 carbon atoms arranged in a honeycomb lattice has been attributed to its extraordinary electronic properties such as high intrinsic mobility, and excellent thermal and electrical conductivity. Those characteristics of graphene have led to extensive applications in the fields of electronic devices, including photovoltaic cells, ultracapacitors and flexible touch screens. [1-2] In addition to the superlative electronic properties, recent studies have demonstrated the graphene’s photo luminescent characteristics, which can expand its application area in optical related fields. [3-5] The photoluminescence (PL) property of graphene is derived by controlling the zero-band gap of graphene. [6] Since the band gap can be tuned by the size, shape, and fraction of the sp2 domains in the sp3 matrix, a variety of graphene derivatives were explored as PL graphene moieties. [7] As an initial endeavor, the optical property of graphene oxide (GO), which is chemically prepared using the modified hummers method from graphite powders, was investigated. The produced GO, which ranged from a few tens of nanometers to several tens of micrometers in the lateral dimension, contained various shapes and nanosized sp2 carbon domains localized by the sp3 carbon structures, resulting in semiconductive and PL properties. [8]