Current trends in carbon-based quantum dots development from solid wastes and their applications (original) (raw)

Urbanization and a massive population boom have immensely increased the solid wastes (SWs) generation and are expected to reach 3.40 billion tons by 2050. In many developed and emerging nations, SWs are prevalent in both major and small cities. As a result, in the current context, the reusability of SWs through various applications has taken on added importance. Carbon-based quantum dots (Cb-QDs) and their many variants are synthesized from SWs in a straightforward and practical method. Cb-QDs are a new type of semiconductor that has attracted the interest of researchers due to their wide range of applications, which include everything from energy storage, chemical sensing, to drug delivery. This review is primarily focused on the conversion of SWs into useful materials, which is an essential aspect of waste management for pollution reduction. In this context, the goal of the current review is to investigate the sustainable synthesis routes of carbon quantum dots (CQDs), graphene quantum dots (GQDs), and graphene oxide quantum dots (GOQDs) from various types SWs. The applications of CQDs, GQDs, and GOQDs in the different areas are also been discussed. Finally, the challenges in implementing the existing synthesis methods and future research directions are highlighted. Keywords Solid wastes • Carbon-based quantum dots • Carbon quantum dots • Graphene quantum dots • Graphene oxide quantum dots Abbreviations 1D-NMR One-dimensional nuclear magnetic resonance 2D-NMR Two-dimensional nuclear magnetic resonance AFM Atomic force microscope BET Brunauer-Emmett-Teller Cb-QDs Carbon-based quantum dots CFU Colony-forming unit CNTs Carbon nanotubes-COOH Carboxyl group CP-MAS-13 C-NMR Solid state cross polarization/magnetic angle spinning 13 C nuclear magnetic resonance spectroscopy CQDs Carbon quantum dots DLS Dynamic light scattering DNA Deoxyribonucleic acid EDX Energy dispersive X-ray EPA Environmental protection agency FTIR Fourier transform infrared GO Graphene oxide GOQDs Graphene oxide quantum dots GQDs Graphene quantum dots GSH Glutathione GSH@rCQDs Glutathione modified reduced carbon quantum dots HOMO Highest occupied molecular orbital HRTEM High-resolution transmission electron microscopy HSQC Heteronuclear single quantum coherence