A laser irradiation synthesis of strongly-coupled VOx-reduced graphene oxide composites as enhanced performance supercapacitor electrodes

A unique technique is present to synthesize three dimensional hierarchical vanadium oxides/reduced graphene oxide composites (denoted as 3D VO x /rGO composites) by laser irradiation over the mixture of V 2 O 5 nanobelts and GO nanosheets. Electron microscopy and X-ray photoelectron spectroscopy (XPS) examinations reveal that polydisperse V 2 O 5 /VO 2 heterostructured nanoparticles form strong coupling with rGO. As a result, a specific capacitance of 252 F g −1 is achieved for 3D VO x /rGO composites when used as supercapacitor electrodes, and the capacitance can retain 92% of the initial specific capacitance even after 10000 cycles at a current density of 100 A g −1 . The improvement of supercapacitor performance is achieved by significantly increase on specific surface area of 3D VO x /rGO composites, which favors the easy access of the electrolyte and provides large electroactive surface, and strong V O C bond between VO x nanoparticles and rGO, which benefits the effective charge transfer. We believe that the facile laser irradiation approach represents a major step not only for the simple and efficient fabrication of high performance electrodes but also in the practical application of laser processing to synthesize other functional hierarchical nanocomposites.