Construction of S-scheme heterojunction of OVs-BiOIO3/N-CQDs/g-C3N4 for degradation of tetracycline

• Published in: Materials science in semiconductor processing 2024-06, Vol.176, p.108268, Article 108268
• Main Authors: Jing, Hongxia, Chen, Bingge, Wang, Xu, Liu, Jun, Wu, Mingliang, Zhang, Xiaoming, Pei, Wangjun
• Format: Article
• Language: English
• Subjects: OVs-BiOIO3/N-CQDs/g-C3N4; Photocatalytic mechanism; S-Scheme heterojunction; Tetracycline
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2024.108268

The proposal of S-scheme heterojunction reveals the principle of a new photocatalysis mechanism, which is superior to the effect of traditional heterojunction, and provides a strong guarantee for the development of photocatalysis technology. In this work, BiOIO3 rich in oxygen vacancies was obtained by a simple calcination method, and then N-CQDs were anchored to the surface of OVs-BiOIO3 to obtain OVs-BiOIO3/N-CQDs composites. The prepared OVs-BiOIO3/N-CQDs and the band gap structure matched g-C3N4 were constructed to form a N-CQDs mediated S-scheme heterostructure, and finally the OVs-BiOIO3/N-CQDs/g-C3N4 ternary composite was obtained. The structure, morphology and photocatalytic efficiency of the composite were obtained by a series of characterization such as SEM, TEM, XRD, FT-IR, PL, EIS, etc. The results show that, when the reaction conditions is 150 °C and 8 h, the catalyst OVs-BiOIO3/N-CQDs/g-C3N4 has the best degradation of 70.5%, which is 1.55 times and 1.24 times OVs-BiOIO3 (45.6%) and g-C3N4 (56.7%) respectively. The results of reactive species trapping experiment showed that ·O2−、·OH play a major role in the photocatalytic process. Conclusively, the mechanism of N-CQDs mediated S-scheme heterojunction is proposed by analyzing all the results.