Supported carbon-dots: a review

Abstract

The synthesis of carbon dots (CDs) that are supported on solid matrices to make solid CD-containing composites has emerged as a promising strategy that can be used to circumvent the drawbacks associated with CDs that are made in solution. To date, various solid matrices such as silica, structured carbons, zeolites, titania, xerogels, and carbon polymers have been used to support the CDs, which allows for the realization to make solid CDs/support nanocomposites. The CDs/support or CDs@support nanocomposites have been demonstrated in many instances to have improved properties (that surpass their unsupported counterparts) ranging from enhanced light response, efficient current density, improved photostability, suppressed nonradiative recombination, enhanced electron-hole pair separation, higher quantum efficiencies, enhanced electron transfer rate, and upconversion photoluminescence properties. In addition, supporting CDs onto a solid matrix can simplify the CD purification processes, lead to better reusability, reduce aggregate formation and also impact on the hygroscopic nature of the CDs. The improved properties that have been demonstrated in CDs/support nanocomposites have opened doors for application in various fields such as photocatalysis, electrochemistry, optics, nanomedicine, sensing, adsorption, and bioimaging, among others. Hence, this review describes the synthesis, properties, importance, and role of CDs/support nanocomposites in various applications.