Preparation and Size Control of Sodium Niobate Nanocube at Various Solvothermal Conditions

Abstract

Nanocube has attracted interest regarding its synthesis by the wet chemical process. Recently, nanocube with perovskite structure such as barium titanate (BaTiO3) and strontium titanate (SrTiO3) has been studied. In this study, sodium niobate (NaNbO3) was prepared by the solvothermal method and its morphology was investigated. The synthesis was carried out using niobium oxide (Nb2O5) and sodium hydroxide (NaOH) as starting materials, also using ethanol as solvent. X-ray diffraction (XRD) confirmed the presence of perovskite NaNbO3 particles and indicated that the phase is orthorhombic NaNbO3. Scanning electron microscopy (SEM) observation revealed the form of NaNbO3 to be nanocube. Reaction times and concentrations of reaction solutions are important factors for synthesis of nanoparticles. The particle size increases with the reaction times, while the particle size decreases with the concentration of the reaction solutions. The smaller crystals were synthesized in a shorter reaction time at the higher concentration of the reaction solutions.

Facile solvothermal synthesis of plate-like submicron NaNbO3 particles

“…32 In addition, compared to the ethanol and methanol mixture, a larger number of nuclei and a lower solubility of Nb 2 O 5 , which leads to less availability of the Nb source, may likely cause the formation of smaller and irregular plate-like particles when ethanol is used solely as the solvent. A decrease in the particle size of NaNbO 3 by ethanol addition is feasible judging from previous reports, 18,19,33 although the experimental conditions including the niobium sources in these previous studies are not identical. In addition, the particle size in other ABO 3 perovskites, such as potassium niobate (KNbO 3 ) and barium titanate, prepared by solvothermal synthesis increases by changing the solvent from methanol to ethanol.…”