Improved photocatalytic activity of Bi₄TaO₈Cl by Gd³⁺ doping

Abstract

Bi 4 TaO 8 Cl and Bi 4 TaO 8 Cl:Gd 3+ photocatalysts were synthesized by the solvothermal technique. The phase, microstructure, optical properties, and photocatalytic activities were investigated. Both Bi 4 TaO 8 Cl and Bi 4 TaO 8 Cl:Gd 3+ have the singly orthorhombic phase and the flower-like hierarchical structure. The Bi 4 TaO 8 Cl: Gd 3+ has higher photocatalytic activity of MB than that of Bi 4 TaO 8 Cl under visible light irradiation. The higher photocatalytic activity of Bi 4 TaO 8 Cl:Gd 3+ is induced by its lower band gap energy, the higher efficiency charge separation, and transfer process, as well as the photogenerated charge carriers with a longer time, which are confirmed by the longer absorption band edge, lower emission intensity, and higher photocurrent under visible light irradiation. The trapping experiments and electron spin resonance results suggest that˙O 2 − is the predominant active species for the photocatalysis of MB by Bi 4 TaO 8 Cl and Bi 4 TaO 8 Cl: Gd 3+ under visible light irradiation. K E Y W O R D S Bi 4 TaO 8 Cl, Gd 3+ doping, hierarchical structure, methylene blue, photocatalysis

Band Gap Engineering in Quadruple-Layered Sillén–Aurivillius Perovskite Oxychlorides Bi7Fe2Ti2O17X (X = Cl, Br, I) for Enhanced Photocatalytic Performance

“…The photocatalytic activities of BFTOX samples are also measured by using MO and RhB (10 mg/L) as the simulated pollutant under light irradiation, the results are displayed in Figure 7. To get a clear contrast, the degradation efficiencies of MO and RhB by BFTOX at different concentrations are calculated by the following equation [36]:…”

“…These results indicate that Sillén-Aurivillius layered oxyhalide materials Bi 4 MO 8 X (M = Nb, Ta; X = Cl, Br) should be a potential novel visible light photocatalyst material. In recent years, Sillén-Aurivillius materials were further extensively studied, such as the construction of heterojunctions [33,34], surface plasmon nanoparticle modification [26,35], element doping [27,36], etc., which proves that this materials have great development potential for photocatalysis, for example Bi 7 Fe 2 Ti 2 O 17 X (X = Cl, Br, I) (BFTOX). In 2022, Yan Gu et al fabricated Bi 7 Fe 2 Ti 2 O 17 Cl successfully by using a one-step flux route and solid-state reaction, and its degradation efficiency of tetracycline (TC) reaches 90% within 90 min, which confirms that BFTOX should be a potential novel visible light photocatalyst material [37].…”