Defects-rich graphene/carbon quantum dot composites as highly efficient electrocatalysts for aqueous zinc/air batteries

The development of metal-free electrocatalysts for the oxygen reduction reaction (ORR) has great influence on many energy conversion devices. In present study, a highly efficient defect-rich graphene/carbon quantum dot composite was successfully obtained and employed as an advanced electrocatalyst for zinc/air batteries. To create more active sites to enhance the performance, one of the most important methods is to form defects in carbon matrix. Other methods are activation process. Here, a defect-rich graphene quantum dots (GQDs) was employed and integrated in the graphene matrix in the first hydrothermal process. Moreover, the following melamine activation during the heat treatment was executed to further fabricate defects on the surface of carbon materials. By innovative combination of the effective two methods, defects-rich carbon composite was synthesized, which lead to an excellent electrocatalytic activity for oxygen reduction reaction, indicative of great potential in the application of zinc/air batteries.