Vanadyl phosphate/reduced graphene oxide nanosheet hybrid material and its capacitance

•The layered structure of VOPO4·2H2O can be maintained to above 400 °C.•VOPO4/RGO hybrid electrodes are reassembled between VOPO4 and GO nanosheets.•The VOPO4 particles are highly dispersed on RGO basal plane.•VOPO4/RGO hybrid electrode exhibits high capacitance and good rate capability.•The good capacitance is ascribed to the synergistic effect between RGO and VOPO4.

The layered structure stability of bulk vanadyl phosphate dihydrate (VOPO4·2H2O) is investigated by using a deintercalation-intercalation reaction process involving short-range swelling, its basal spacing can be reversibility controlled and the layered structure can be maintained to above 400 °C. By using delaminated vanadyl phosphate (VOPO4) nanosheets in 2-propanol, VOPO4/reduced graphene oxide (RGO) hybrid electrode materials for supercapacitor with different mass ratios of VOPO4 nanosheets to graphene oxide (GO) nanosheets have been prepared based on a nanosheet reassembling reaction between the exfoliated VOPO4 nanosheets and GO nanosheets and followed by calcinating in a tubular furnace at 400 °C for 3 h under N2 atmosphere, and their electrochemical properties are systematically investigated by cyclic voltammetry and galvanostatic charge-discharge in 0.5 M K2SO4 electrolyte. The VOPO4/RGO hybrid electrode with a mass ratio of VOPO4/RGO = 1 exhibits a high specific capacitance of 378 F g−1 at a scan rate of 5 mV s−1 with a good rate capability. This method broadens the application filed of VOPO4 nanosheets, and also supplies promising electrode candidates for supercapacitor.

Graphical abstractVOPO4/RGO hybrid electrode materials have been prepared based on a nanosheet reassembling reaction between VOPO4 and GO nanosheets and followed by calcinating in a tubular furnace at 400 °C for 3 h under N2 atmosphere. The VOPO4/RGO hybrid electrode with a mass ratio of VOPO4/RGO = 1 exhibits a high specific capacitance of 378 F g−1 at a scan rate of 5 mV s−1 with a good rate capability in 0.5 M K2SO4 electrolyte.Figure optionsDownload full-size imageDownload as PowerPoint slide