NaNbO₃ synthesis using combined EDTA/Citrate complexation

The synthesis methodologies and reaction parameters directly affect the structure and morphology of materials such as perovskite-type compounds. In this work, sodium niobate (NaNbO₃) was produced using the combined EDTA/citrate complexation method, with ratios of 1:1:3 metal ions (sodium and niobium): EDTA: citric acid, and pre-treatment at 230 °C and temperature calcination at 700 °C. The sample was analyzed using XRD with Rietveld refinement and UV-Vis ERD. The study revealed that the material has an orthorhombic crystal structure and P2₁ma space group identified by CIF 9014103. Based on the atomic positions obtained from Rietveld refinement, it was observed that each NaNbO₃ sample maintained a basic perovskite network, particularly the BO₆ polyedra centered on the niobium cation site, with lattice parameters of a = 5.565Å, b = 7.774 Å and c = 5.521 Å. The crystallite size of sodium niobate was obtained using a Scherrer-type relationship, with a value of 169.91 nm. But the synthesis method promoted significant distortions within the NbO₆ coordination polyhedra. The bandgap value obtained was 2.69 eV, which is lower than those reported in the literature (~3.4 eV). These variations can be attributed to changes in the crystalline structure and particle morphology, which may undergo phase transitions that affect their electronic properties and, consequently, their bandgap. Therefore, the synthesis method used is effective in producing NaNbO₃ with tunable properties, expanding its potential for technological applications such as hydrogen production and storage.