Graphene quantum dots and their possible energy applications: A review

As new carbon-based materials, graphene quantum dots (GQDs) many advantages due to the additional unique properties that arise from their nanoscale small size. GQDs are expected to be suitable for various applications. For use of GQDs in various fields, mass production is critically required. To date, many methods for preparing GQDs with good properties and high yield have been introduced. The main synthesis strategies are known as bottom-up and top-down methods. Synthesis of GQDs from small organic molecules, known as the bottom-up approach, is appropriate for controlling the size of GQDs but requires multistep organic reactions and purification at each step. However, the top-down approach of breaking the carbon-carbon bonds of a large carbon source is easy and simple, and therefore suitable for mass production. Here, we briefly introduce the solution-process synthesis of GQDs using a top-down method and recent energy-related applications such as capacitors, lithium ion batteries, and solar cells.