Scalable synthesis of high-purity TiO 2 whiskers via ion exchange method enables versatile applications.

In this work, high-purity titanium dioxide (TiO 2 ) whiskers with different crystal forms were synthesized via ion exchange and controlled calcination methods. TiO 2 whiskers are of 5-10 μm in length with a length-to-diameter ratio of 10-20. A systematic investigation was established to explore the hydration process of K + /H + exchange, anatase-rutile transformation in the calcination process and the applications of TiO 2 whiskers. Compared with the other strategies previously used for the synthesis of TiO 2 whiskers, it was found that large-scale production was obtained under mild reaction conditions, which represented a facile and mild route for industrial production and expanded the versatile applications of TiO 2 whiskers. Moreover, with the addition of nano TiO 2 colloid as a special accelerant, the calcination process yielding uniform morphology and controllable crystal form was explored. Confirmatory experiments indicated that anatase and rutile TiO 2 whiskers respectively show excellent photocatalytic activities and unique carrier performance for fabricating functional whiskers.