Controlled synthesis and electrochemical properties of vanadium oxides with different nanostructures

摘要

Vanadium oxides (V3O7H2O and VO2) with different morphologies have been selectively synthesized by a facile hydrothermal approach using glucose as the reducing and structure-directing reagent. The as-obtained V_3O_7-H_2O nanobelts have a length up to several tens of micrometers, width of about 60-150 nm and thickness of about 5-10 nm, while the as-prepared VO_2(B) nanobelts have a length of about 1.0-2.7 μm, width, 80-140 nm and thickness, 2-8 nm. It was found that the quantity of glucose, the reaction temperature and the reaction time had significant influence on the compositions and morphologies of final products. Vanadium oxides with different morphologies were easily synthesized by controlling the concentration of glucose. The formation mechanism was also briefly discussed, indicating that glucose played different roles in synthesizing various vanadium oxides. The phase transition from VO_2(B) to VO_2(M) were investigated and the phase transition temperature of the VO_2(M) appeared at around 68 °C. Furthermore, the electrochemical properties of V_3O_7-H_2O nanobelts, VO_2