Graphene quantum dots: versatile photoluminescence for energy, biomedical, and environmental applications

Photoluminescence is one of the most outstanding features of graphene quantum dots. Because of their versatile photoluminescence, large surface area, high photostability, low cytotoxicity, and excellent biocompatibility, graphene quantum dots show promising applications in various fields, and herein they have become the research focus in recent years. In this review article, we summarize the latest research progress of graphene quantum dots, focusing on their photoluminescence features and promising applications. This article also summarizes the most recent researches on the upconversion by the use of a femtosecond laser. Perspectives on this topic were presented on the basis of the current research status. We hope that this article could help gain an in-depth understanding of photoluminescent graphene quantum dots, and herein stimulate continued interest and endeavors in this research area.