SiO2@TiO2:Sm3+ with Diverse Phase Structure and Morphology: Photoluminescence and Simulated Solar Light-Activated Photodegradation Properties

摘要

abstract_textpSm3+ doped SiO2@TiO2 nanospheres with diverse morphology have been successfully prepared. The size of SiO2 could be adjusted not only by changing the etching time but also through varying the coating method of TiO2. Sol-gel and solvothermal methods were adopted to investigate the effect of coating conditions on morphology and properties of the products. Photocatalytic results showed that core-shell structures obtained by solvothermal method possess the highest photodegradation efficiency, which reached 98 for degradation of methyl orange within 30 min under simulated solar light irradiation. The trapping experiments were performed and the possible photocatalytic mechanism was proposed. Yolk-shell structures obtained through solvothermal method exhibited the strongest orange-red emission intensity, however, for the samples obtained through a sol-gel process, the luminescence intensities of the products showed the oppose trend, which is the result of a combination of light utilization, specific surface area and crystallinity. In addition, the X-ray diffraction analysis results of products calcined at 900 degrees C manifested that a certain amount of Sm3+ ions inhibit the formation of rutile phase effectively, but the inhibitory effect is not proportional to its concentration. This article provides deeper insight into photocatalytic and luminescence bi-functional properties of SiO2@TiO2:Sm3+ nanospheres with diverse morphology obtained through different preparation methods./p/abstract_text