One-Pot Synthesis and Characterization of VO2(B) with a Large Voltage Window Electrochemical Performance in Aqueous Solution

B-type vanadium dioxide (defined as VO2(B)) nanobelts were synthesized through using commercial ammonium metavanadate, oxalic acid via one-step hydrothermal technique. The structure of VO2(B) was characterized using different instruments. N2 adsorption-desorption isotherms revealed that the VO2(B) nanobelts were porous structures where BET surface area was 10.4 m2·g−1, the pore volume was 0.0687 cm3/g, and the average pore size was 42.7 nm. Furthermore, the VO2(B) nanobelts as supercapacitors electrode exhibited a large voltage window (−0.8~1.0 V). The measured capacitance was based on the pseudocapacitance. When the discharge current density is 0.5, 1, and 10 A·g−1, the VO2(B) shows the specific capacitance of 287, 246, and 222 F·g−1, respectively.