Obtaining and Characterization of Porous Microspheres of Nb2O5, TiO2 and their Mixtures by Internal Gelation

The utilization of niobium oxide and its compounds has seen significant growth in recent years, with applications in ion exchangers, adsorbents, catalysts, supports, photocatalysts, and components of lithium and sodium batteries and capacitors. Brazil, having the world's largest niobium reserves, aims to lead in related technologies. This study synthesized mesoporous Nb2O5 microspheres via emulsification/internal gelation from reactive NbCl5, developing a method to stabilize niobium pentachloride in aqueous solution. The microspheres were characterized for morphology, structural integrity (SEM), crystalline structure (XRD), and specific surface area and porosity (gas adsorption, N2). Additionally, TiO2 microspheres (from TiCl4) and their mixtures with Nb2O5 in mol ratios 81/19 and 93/7 were obtained and characterized. The stabilization of NbCl5 in aqueous solution was efficient, enabling the synthesis of Nb2O5 microspheres and their TiO2 mixtures.