Single‐Crystal‐like Mesoporous SrTiO₃ Spheres with Enhanced Photocatalytic Performance

Abstract

Single-crystal-like mesoporous strontium titanate (SrTiO 3 ) submicrometer spheres with a wormhole-like structure were successfully synthesized by a facile hydrothermal method using polyvinyl alcohol (PVA) as additive. The microstructure was studied by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, selected area electron diffraction, and N 2 -physisorption techniques. The results demonstrated that the average pore size of the as-synthesized SrTiO 3 mesoporous spheres can be tuned in the range of 4.5-16.1 nm by varying reaction time and adding PVA of different concentrations. The mesopores structure of the sample synthesized without PVA was different from that of the sample synthesized with PVA. For the former, the pores were contained in single-crystal particles in the presence of thick pore wall; in contrast, for the latter the pores occurred as voids between primary nanoparticles. On the basis of the investigation on the growth process, oriented aggregation of nanocrystallites was suggested to be the dominant growth mechanism, which was accompanied by the ripening process to form the high-quality mesoporous spheres. The photocatalytic activities of series samples were investigated through the degradation of rhodamine-B under exposure to the ultraviolet radiation (k 5 200-400 nm). The results indicated that the photocatalytic activities were the function of the reaction time and PVA concentration, Because both of them played an important role in the crystallinity, pore structure, and adsorption capacity in dark of the as-synthesized mesoporous SrTiO 3 spheres.

Basic Molten Salt Route to Prepare Porous SrTiO3 Nanocrystals for Efficient Photocatalytic Hydrogen Production

“…Such an agglomeration process can also lead to the formation of pores. A similar crystal growth process was observed by Xu et al [17] With polyvinyl alcohol (PVA) as an additive, mesoporous SrTiO 3 with a wormholelike structure formed by an oriented aggregation of nanocrystals and also exhibited single-crystal-like character.…”

Enhanced Photodecomposition of Methylene Blue in Water with Sr1−xKxTiO3−δ@PC-polyHIPEs under UV and Visible Light

“…According to IUPAC classification, the N 2 adsorptiondesorption curves of these three samples belong to the indicating that the samples are of macroporous structure [26]. As the pores in PC-polyHIPEs are 30∼100 m in diameter, over such material, the N 2 adsorption-desorption isothermal curve does not exactly reflect the pore situation.…”

A simple solvothermal process to synthesize CaTiO3 microspheres and its photocatalytic properties

“…CaTiO 3 has potential application in the fields of electricity [18], optics [19], catalysis [20] and biology [21]. On the other hand, it has reported that perovskite-type oxides, such as SrTiO 3 , could perform high photocatalytic properties [22]. So far, however, there have been a few studies on the photocatalytic properties of CaTiO 3 .…”