Controllable synthesis of sodium titanates using facile ball milling method

Abstract

In this study, we demonstrated a controllable synthesis of sodium titanates (Na2Ti6O13 and Na2Ti3O7) using simple mechanochemical (dry ball milling) method. Although the titanates were obtained after calcination, however, the milling speed and duration control the phase type, crystallinity, purity and morphology of the as-synthesized materials. At low milling speed (200 rpm), cuboid-like Na2Ti6O13 nanostructures were the dominant phase, where the purity and crystallinity enhanced for prolonged milling duration (20 h). The nanorod-like Na2Ti3O7 phase is the dominant phase at higher milling speeds (≥300 rpm) with minor traces of Na2Ti6O13 phase that disappeared at prolonged milling. In contrast to wet chemical methods, no byproducts such as titanic acids or unreacted materials were detected in the materials synthesized by the mechanochemical method.