Synthesis of quasi-core–shell Co-doped ZnO/graphene nanoparticles

Abstract Co-doped ZnO/graphene quasi-core–shell hybrid nanoparticles with a reduced graphene oxide (RGO) shell around the Zn 0.98 Co 0.02 O core are synthesized by a facile chemical process. X-ray diffraction (XRD) analysis reveals that nanoparticles consist of wurtzite ZnCoO and graphene without the impurity phase. The successful doping of Co ions into the ZnO host is illustrated by the XRD lines shifting and XPS spectra of Co ions. High-resolution transmission electron microscopy (HRTEM) image shows that the Zn 0.98 Co 0.02 O is fully covered with the RGO shell, verifying that Zn 0.98 Co 0.02 O/RGO hybrid structure is quasi-core–shell structure. Raman spectra indicate that graphene oxide is reduced to graphene successfully. The red-shift of the characteristic E 2H peak and 2D peak of Zn 0.98 Co 0.02 O/RGO imply the electron interaction between Zn 0.98 Co 0.02 O and RGO. Magnetization measurement demonstrates that the Zn 0.98 Co 0.02 O/RGO nanoparticles present canted antiferromagnetic behavior, which has a promising application in semiconductor spintronic devices.