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.

VOPO4/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 as PowerPoint slide