Reconstruction of interface band structure to construct SrTiO3/BiOBr Z-scheme heterojunction for efficient oxytetracycline degradation and hydrogen recovery

• Published in: Applied surface science 2025-03, Vol.684, Article 161977
• Main Authors: Wang, Kai, Yu, Xiaojiao, Liu, Zongbin, Yang, Fan, Zhang, Jian, Niu, Jinfen, Yao, Binghua
• Format: Article
• Language: English
• Subjects: 0D/2D SrTiO3/BiOBr; Degradation mechanism; Toxicity assessment, Hydrogen evolution; Z-scheme heterostructure
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.161977

[Display omitted] •Successful fabrication of 0D/2D SrTiO3/BiOBr heterostructure photocatalyst.•The SrTiO3/BiOBr composites showed efficient photocatalytic performance.•SrTiO3/BiOBr exhibited an excellent Z-scheme charge transfer mechanism.•The photocatalytic mechanism of OTC degradation and H2 evolution were proposed. Heterojunction construction is an innovative and widely applied method for raising the photocatalytic activity of catalytic systems. Using the microwave hydrothermal technique, heterojunctions with different SrTiO3 to BiOBr mass ratios were synthesized. After exposure to visible light for 30 min, the optimal SrTiO3/BiOBr heterojunction photocatalyst demonstrated strong photocatalytic activity (94.8 %) for oxytetracycline (OTC) degradation, outperforming pure SrTiO3 (46.9 %) and BiOBr (55.9 %). The OTC degradation mechanism was speculated based upon experimental measurements, theoretical calculations, and free radical scavenging experiments, and OTC toxicity was evaluated using T.E.S.T simulation software and antibacterial. Using the optimal SrTiO3/BiOBr heterojunction catalyst, the hydrogen (H2) evolution rate was as high as 65.4 μmol/g/h, which was 3.2 times higher than that of SrTiO3. In addition, the H2 evolution rate of the optimal heterojunction catalyst in the OTC system reached 36.1 μmol/g/h, corresponding to an OTC degradation rate of 96.4 %. The band structure and density functional theory investigation indicated that the internal electric fields generated by the zero-dimensional/two-dimensional Z-scheme SrTiO3/BiOBr heterojunction helped to maintain good redox performance and promote charge transfer, thereby enhancing the catalytic activity of the heterojunction system.