Facile synthesis of novel gully-like double-sized mesoporous structural Sr-doped ZrO2–TiO2 composites with improved photocatalytic efficiency

Abstract Using polystyrene (PS) microspheres as an auxiliary template, a kind of novel gully-like Sr-doped ZrO2–TiO2 composites with the heterogeneous structure were successfully prepared by a simple instant centrifugation with one-step hydrolysis method. The Sr-doped ZrO2–TiO2 composites consisted of the tetragonal phase ZrO2, orthogonal phase SrZrO3 and anatase phase TiO2, showing a homogeneous concave and convex shape, similared to the naturally occurring gully terrain in nature, with a double-sized mesoporous structure. The SrZrO3 was prepared by the synthetic method in this study, which provided a new reference for the subsequent synthesis of SrZrO3. At the same time, Sr-doped ZrO2–TiO2 composites showed higher photocatalytic activity compared with the monomer and non-strontium-doped TiO2-ZrO2 under multi-mode photocatalytic conditions such as ultraviolet light, visible light, and simulated sunlight. The hydrogen production of Sr-doped ZrO2–TiO2 was 2.9 times and 4.4 times higher than that of TiO2–ZrO2 and TiO2, indicating that Sr-doped played a synergistic role in photocatalytic activity experiments. Finally, by the capturing experiment of gully-like Sr-doped ZrO2–TiO2, it was confirmed that h+,·OH, O2•− were active species in the photodegradation of malachite green, and the possible mechanism of the photocatalytic reaction was deduced.