Vanadium pentoxide nanobelts and nanorolls: from controllable synthesis to investigation of their electrochemical properties and photocatalytic activities

摘要

Uniform V_2O_5 centre dot x H_2O nanobelts with high aspect ratios and ultra-long V_2O_5 centre dot xH_2O nanorolls with novel scroll-like structures were synthesized on a large scale by a simple hydrothermal growth route using NH_4VO_3 as the raw material in the presence of different acids at 180 deg C for 24 h. Their morphologies were observed by scanning electron microscopy (SEM). X-ray powder diffraction measurement and thermal gravimetric analysis revealed the composition of nanobelts and nanorolls to be V_2O_5 centre dot 0.9H_2O and V_2O_5 centre dot 0.6H_2O, respectively. The possible mechanisms of formation of the nanobelts and nanorolls were schematically elucidated based on the layered structure of vanadium pentoxide. In addition, corresponding anhydrous V_2O_5 nanostructures with better crystallinity were obtained by calcining the precursors of V_2O_5 centre dot 0.9H_2O nanobelts or V_2O_5 centre dot 0.6H_2O nanorolls. Furthermore, we have investigated the electrochemical intercalation properties with Li~+ and the photocatalytic activities of the synthesized V_2O_5 centre dot 0.9H_2O nanobelts, V_2O_5 centre dot 0.6H_2O nanorolls and their corresponding post-annealing products. It was observed that the morphologies and compositions of the synthesized products had an evident influence on the electrochemical intercalation properties with Li~+ and photocatalytic activities.