Carbon quantum dots for advanced electrocatalysis

Zero-dimensional (0D) carbon quantum dots (CQDs), as a nanocarbon material in the carbon family, have garnered increasing attention in recent years due to their outstanding features of low cost, nontoxicity, large surface area, high electrical conductivity, and rich surface functional groups. By virtue of their rapid electron transfer and large surface area, CQDs also emerge as promising functional materials for the applications in energy-conversion sectors through electrocatalysis. Besides, the rich functional groups on the surface of CQDs offer abundant anchoring sites and active sites for the engineering of multi-component and high-performance composite materials. More importantly, the heteroatom in the CQDs could effectively tailor the charge distribution to promote the electron transfer via internal interactions, which is crucial to the enhancement of electrocatalytic performance. Herein, an overview about recent progress in preparing CQDs-based composites and employing them as promising electrode materials to promote the catalytic activity and stability for electrocatalysis is provided. The introduced CQDs could enhance the conductivity, modify the morphology and crystal phase, optimize the electronic structure, and provide more active centers and defect sites of composites. After establishing a deep understanding of the relationship between CQDs and electrocatalytic performances, the issues and challenges for the development of CQDs-based composites are discussed.