ZHAO Wei, ZHANG Qi, RONG Jiacheng, WANG Heng, WANG Hugang, LI Mingxiao

(Materials Science and Engineering, Tianjin Chengjian University, Tianjin 300384, China)

Abstract: SrTiO₃ microspheres were synthesized by combing hydrothermal process and post heat treatment using the amorphous TiO₂ microspheres as the template, and then TiO₂ was coated on the surface of SrTiO₃ microspheres by hydrolysis of titanium sulfate. The samples were characterized by XRD, SEM, and so on. The photocatalytic properties of the as-prepared TiO₂/SrTiO₃ microspheres were evaluated under the irradiation of ultraviolet light with methylene blue (MB) as the target pollutant. The results show that Ti/Sr mass ratio, aging conditions and heat treatment process have an important effect on the structure of the microspheres. When the concentration of the KOH aging solution is 1.0 mol/L, some particles are attached on the surface of the microspheres; as the concentration increases, the coating particles increase accordingly. The higher the Ti/Sr mass ratio, the easier it is for TiO₂ to adhere to the surface of the microspheres, the wrap layer becomes thicker, and the surface of the microspheres becomes smoother. The pure TiO₂/SrTiO₃ composite was obtained by the heat treatment process which contributed to the crystallization of SrTiO₃. The composite microspheres maintain the morphology of the TiO₂ template with a diameter of 0.5 μm, and the surface of the microspheres shows micro-nano hierarchical structure. The composite material can decolorize the methylene blue solution within 6 hours under the irradiation of a UV lamp with a wavelength of 360 nm.
Key words: monodisperse; TiO₂/SrTiO₃; submicron sphere; photocatalytic performance