Surface sprouting growth of Na2Nb2O6·H2O nanowires and fabrication of NaNbO3 nanostructures with controlled morphologies

Abstract

The one-dimensional (1D) Sandia octahedral molecular sieves (SOMS) Na2Nb2O6·H2O nanowires were prepared by the reaction of Nb powder with NaOH via a one-step hydrothermal methods. The products were characterized by SEM, TEM, XRD, IR and EDX. A plausible sprouting growth mechanism is proposed for the formation of Na2Nb2O6·H2O nanowires based on the systematic investigation. Na2Nb2O6·H2O nanoribbons-based complex flowerlike structure were first grew on the metallic niobium surface, the growth process of SOMS nanowire is similar to the plant seed sprouting and growing, Na2Nb2O6·H2O nanowires were finally formed at the depletion of metallic niobium powder. In the end, we showed that Na2Nb2O6·H2O nanowires is hydrothermally synthesized in the 15M NaOH solution at 423K, which can be easily converted into NaNbO3 nanowires by calcination, while the NaNbO3 cubes were obtained through the same hydrothermal process at a higher temperature of 453K.