A novel synergy of Er3+/Fe3+ co-doped porous Bi5O7I microspheres with enhanced photocatalytic activity under visible-light irradiation

• Published in: Applied catalysis. B, Environmental Environmental, 2017-05, Vol.205, p.421-432
• Main Authors: Liu, Yongbao, Zhu, Gangqiang, Gao, Jianzhi, Zhu, Runliang, Hojamberdiev, Mirabbos, Wang, Chenghui, Wei, Xiumei, Liu, Peng
• Format: Article
• Language: English
• Subjects: Absorption; Bisphenol A; Catalytic activity; Chloramphenicol; Decomposition; Degradation; Doping; Erbium; Free radicals; Infrared radiation; Iron; Irradiation; Light emitting diodes; Light irradiation; Microsphere; Microspheres; Phenols; Photocatalysis; Photocatalysts; Photocatalytic activity; Photodegradation; Pollutants; Porous; Radicals; Superoxide; Thermal decomposition; Up-conversion; Upconversion
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2016.12.061

[Display omitted] •A novel photocatalyst of Er3+/Fe3+ co-doped porous Bi5O7I microspheres is reported.•Er3+/Fe3+ co-doped Bi5O7I showed high photocatalytic performance for phenol, bisphenol A, and chloramphenicol.•The upconversion effect of Er3+ generates the enhanced photocatalytic activity of Bi5O7I.•The improved photocatalytic property can also be attributed the separation of photo-induced electron-hole pairs by Fe3+. Uniform porous Bi5O7I (BOI) microspheres photocatalysts co-doped with Fe3+ and Er3+ were synthesized by a solvothermal-thermal decomposition method, in which Er3+ with upconversion properties could transform infrared light beyond the absorption edge of Bi5O7I into visible light, and also activate the Fe3+-doped Bi5O7I (Fe-BOI). The photocatalytic activities of the photocatalysts were evaluated by the degradation of three typical colorless model pollutants, i.e., phenol, bisphenol A (BPA), and chloramphenicol (CAP), under visible light irradiation (800nm>λ>400nm). The results showed that the photocatalytic activity of Fe3+/Er3+ co-doped Bi5O7I (Er/Fe-BOI) was much higher than that of the undoped, Fe3+-doped and Er3+-doped Bi5O7I photocatalysts. In addition, Fe3+/Er3+ co-doped Bi5O7I exhibited photocatalytic activity under a 3W LED lamp (red light, λ=630nm) with the wavelength beyond the absorption edge of Bi5O7I, which further testified that the upconversion effect of Er3+ generates the enhanced photocatalytic activity of Bi5O7I. Photodegradation mechanism was systematically studied by using various radical quenchers and it was revealed that photogenerated holes (h+) and superoxide radicals (O2−) actively participated, whereas hydroxyl (OH) radicals had negligible contribution in photodegradation of phenol.