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• The visible light corresponding BiOBr nanosheets were prepared by one-step water bath heating method. • The combination of diatomic doping and nanosheet construction can promote the photocatalytic performance of BiOBr. • The BiOBr nanosheets can rapidly degrade Tetracycline hydrochloride and high concentration RhB. Designing efficient photocatalysts is essential for improving photocatalytic performance. Separation efficiency of photogenerated carriers is one of the key factors affecting photocatalytic performance. Combining the construction of two-dimensional materials with elemental doping can further improve the separation of photogenerated carriers. As expected, the performance of the samples produced by Fe and Cu co-doping was superior to that of pure BiOBr and mono-doped samples, with significant improvements in the photocatalytic degradation of both rhodamine B and tetracycline. The dopant of excess metal element atoms can form impurity energy levels in the forbidden band that effectively facilitate the separation and migration of photogenerated carriers. Meanwhile, the thin-layer two-dimensional structure can effectively shorten the bulk charge carrier transmission distance and improve the transmission efficiency. This study not only provides a simple, green and low-cost method for combining iron and copper into composites materials at same time but also confirmed that the photocatalytic performance of BiOBr was strongly influenced by different Fe and Cu contents. [ABSTRACT FROM AUTHOR]

A visible-light-responsive hybrid photocatalyst, K-doped g-C 3 N 4 /BiOBr, has been synthesized by K-doped g-C 3 N 4 (K–CN) and BiOBr. The property of photocatalysts was characterized by XRD, FT-IR, TEM, SEM, DRS, PL, EIS and HPLC. The photocatalytic activity of K-doped g-C 3 N 4 /BiOBr was evaluated by degradation of Rhodamine B (RhB) and tetracycline hydrochloride under visible-light irradiation. The K-doped g-C 3 N 4 /BiOBr hybrid photocatalyst which contains K–CN with mass fraction of 20% (20K–CN/BiOBr) shows the best degradation efficiency of RhB. The degradation efficiency of RhB (20 mg/L) can be achieved to 99% and the degradation efficiency of tetracycline hydrochloride by BiOBr decreased with the increase of K-doped g-C 3 N 4 doping. The results of photocurrent and EIS assumed that the tight coupling between K–CN and BiOBr can enhance the separating efficiency of photo-generated carrier. In addition, the capture experiment proof that h+ is the primary active substance in the system of reaction and ·OH is the auxiliary active substance. After five degradation experiments, the efficiency of the degradation of Rhodamine B by the sample can still reach 90%, which proves that the samples are stable. A new and efficient method is provided in this work to solve the pollution of organic dyes and antibiotics. [ABSTRACT FROM AUTHOR]

Bi 4 O 5 I 2 /Bi 2 O 2 CO 3 p-n heterojunction photocatalysts were synthesized by utilizing different ratios of solvent via a one-pot solvothermal method in the process of synthesizing Bi 4 O 5 I 2 and Bi 5 O 7 I. The structure, morphology and photoelectric properties of the prepared samples were characterized by XRD, SEM, TEM, FTIR, XPS and DRS. Through the estimated photocatalytic degradation of pollutants such as tetracycline hydrochloride (TC) and rhodamine B (RhB), it was found that the Bi 4 O 5 I 2 /Bi 2 O 2 CO 3 (the ratio of ethylene glycol and distilled water in the solvent was 3/5) heterojunction photocatalyst had the highest degradation, with the removal of up to 80.6% from all prepared samples within 30 min under visible light irradiation; this heterojunction also showed better RhB degradation performance. The presence of an internal electrostatic field between the p-type semiconductor Bi 4 O 5 I 2 and n-type semiconductor Bi 2 O 2 CO 3 effectively suppressed the recombination of photoinduced electron–hole pairs. Moreover, a feasible mechanism was proposed. [ABSTRACT FROM AUTHOR]

In this work, Bi 4 O 5 I 2 -Bi 2 O 2 CO 3 -BiOCl 0.8 I 0.2 n-p-n heterojunction was synthesized by in-situ growth method. Different types of BiOX (X = Br, Cl and I) materials were combined to optimize the charge separation of prepared heterogeneous junction so as to improve the photocatalytic performance. It had been proved by various characterization methods that the charge carrier recombination would be greatly suppressed under the action of internal electric field at the interface when n-p-n heterojunction was formed. Specially, 20-Bi 4 O 5 I 2 -Bi 2 O 2 CO 3 -BiOCl 0.8 I 0.2 presented the best photocatalytic performance, which could degrade 99% of Rhodamine B (RhB) in 60 min under 500 W Xe lamp source. BiOCl 0.8 I 0.2 improves the performance of photocatalytic and broaden the light absorption range of pure BiOI. This work provides a new perspective to design ternary structures that enhance photocatalytic performance. [Display omitted] [ABSTRACT FROM AUTHOR]