Carbon nanodots: Mechanisms of photoluminescence and principles of application

Carbon nanoparticles are relatively new and promising area of research receiving increasingly growing attention. They are small, cheap to produce, and do not contain potentially toxic components while showing bright and tunable light emission. They can thus potentially replace inorganic quantum dots in applications such as bioimaging, solar cells, photocatalysis and sensor applications. Units of nanometer size carbon dots (CDs) stable in aqueous solutions with photoluminescence in visible range can be obtained in one-step synthesis from variety of available materials. Currently, application of CDs is restricted by the lack of understanding of fundamental relationship between synthesis routes (and ingredients including raw materials), CDs' structure and CDs' properties. This review is focused on evaluating recent trends in CDs research and application, including CDs synthesis, understanding of their photoluminescent properties. We also discuss the principles, perspectives and current limitations in CDs applications.