Microstructure, optical, photoluminescence properties and the intrinsic mechanism of photoluminescence and photocatalysis for the BaTiO3, BaTiO3/TiO2 and BaTiO3/TiO2/CeO2 smart composites

• Published in: Optical materials 2021-08, Vol.118, p.111273, Article 111273
• Main Authors: Wang, Shifa, Tang, Shengnan, Gao, Huajing, Chen, Xiangyu, Liu, Hao, Yu, Chuan, Yin, Zijuan, Zhao, Xinxin, Pan, Xudong, Yang, Hua
• Format: Article
• Language: English
• Subjects: BaTiO3; Hydrothermal synthesis method; Methylene blue; Photocatalytic activity; Photoluminescence properties; Smart materials
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2021.111273

The BaTiO3/TiO2/CeO2 smart composites with double type II band arrangement structures were synthesized by a hydrothermal synthesis method. This study attempted to improve the photoluminescence performance and photocatalytic activity by introducing anatase TiO2 or two kinds of metal species, cubic CeO2 and anatase TiO2, fabricated as BaTiO3/TiO2 or BaTiO3/TiO2/CeO2 smart composites. Rietveld refinement analysis revealed a typical tetragonal structure with P4mm(99) space group of pure BaTiO3 smart materials and BaTiO3/TiO2/CeO2 smart composites consist of tetragonal BaTiO3, cubic CeO2 and anatase TiO2. The surface morphology, color, optical absorption coefficient, photoluminescence performance and photocatalytic activity showed strong CeO2 content - dependent behavior. For the pure BaTiO3 smart materials, three obvious emission peaks at 420, 460 and 470 nm can be observed when the excitation wavelength is 295 nm. The introduction of TiO2 into the pure BaTiO3 smart materials to construct BaTiO3/TiO2 smart composites resulted in redshift of emission peak. When TiO2 and CeO2 were introduced into the pure BaTiO3 smart materials, the intrinsic fluorescence emission peak of BaTiO3 was almost quenched. Oxygen vacancy, Ce-4f level and impurity level promote the electron hole pair recombination, which is beneficial to enhance the photoluminescence of the system, but unfavorable to their photocatalytic activity. The BaTiO3/(15 wt%) TiO2/(15 wt%) CeO2 smart composites exhibit a highest photocatalytic activity for the photocatalytic degradation of methylene blue under ultraviolet light irradiation. •A hydrothermal synthesis method have been used to synthesize the BaTiO3/TiO2/CeO2 smart composites.•The optical, photoluminescence properties and photocatalytic activity of BaTiO3/TiO2/CeO2 smart composites were compared.•Possible photoluminescence and photocatalysis mechanisms have been proposed.