Effect of temperature and reaction time on the structural and textural transformation of niobium pentoxide via alkaline hydrothermal treatment

The present study evaluates the structural transformation of niobium pentoxide (Nb 2 O 5 ) through reaction with sodium hydroxide (NaOH) under hydrothermal conditions, focusing on the effects of temperature and reaction time on its crystalline morphology. In this parametric study, Nb 2 O 5 particles were reacted with NaOH at 160 °C and 180 °C temperatures and reaction times of 90, 120, and 180 min. The resulting materials were characterized by X-ray diffraction (XRD), laser diffraction particle size analysis (LDPSA), specific surface area analysis (BET), and scanning electron microscopy (SEM). XRD confirmed the formation of NaNbO₃ and highlighted changes in the crystalline structure. LDPSA showed particle size redistribution due to the reaction conditions. BET analysis revealed significant surface area enhancements, with the sample treated at 180 °C for 90 min achieving the highest value. SEM images confirmed morphological changes induced by temperature and reaction time. These results underscore the importance of precise control over synthesis parameters to optimize the textural and structural properties of niobium oxide for advanced applications, such as active polymer packaging systems, catalysis, adsorption, and biomedicine.