Mesoporous SrTiO₃ nanowires from a template-free hydrothermal process

Abstract

High-yield SrTiO3 nanowires (NWs) with accessible mesoporosity were synthesized through a template-free hydrothermal process. The highest surface area of 145 m2 g−1 with the pore volume of 0.43 cm3 g−1 was confirmed when the Ti/Sr molar ratio was fixed at 1 : 1.05 in the precursors. Unlike the previously reported preparation of mesoporous one-dimensional materials, the present method required no substrates, organic templates or additives, making it low cost and environmentally friendly. The formation mechanism of the mesoporous NWs was investigated by sampling and analyzing the reaction mixtures after different autoclaving time. It was suggested that the crystal growth and morphology evolution was governed by the Ostwald ripening process and the Kirkendall effect. The same strategy was also applied for successful preparation of mesoporous BaTiO3 NWs and mesoporous SrTiO3 nanorods and nanocubes. The obtained mesoporous SrTiO3 NWs were used for photodegradation of organic dyes and proved to be useful photocatalysts with excellent reusability.