▎ 摘　　要

Hexagonal graphene quantum dots (GQDs) derived from plant leaves with diameters in the range of 5-7 nm with zig-zag edges were synthesized and its intrinsic defects and magnetic properties were investigated. Our results showed paramagnetic behavior below 15 K. The origin of paramagnetism was ascribed to the edge spin effect presented in the GQDs and largely based on the GQDs hexagonal nanoislands with zigzag edges. Our results are further consistent with the theoretical prediction. The excellent spin and magnetic properties exhibited by these GQDs could potentially lead to new and advanced nano spin-manipulation devices. Crown Copyright (C) 2016 Published by Elsevier B.V. All rights reserved.