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In this paper, MoS2@MIL-53(Fe) (noted as MSMF) metal–organic backbone adsorption photocatalysts were successfully prepared by a solvothermal method. For the degradation performance of MSMF catalysts on tetracycline pollutants, the effects of MoS2 doping ratio, reaction mode, and contaminant concentration on the degradation performance were investigated. And the materials were characterized by XRD, XPS, SEM, BET, PL, and ESR to investigate the reaction mechanism. The results showed that the optimal synthesis mass ratio of MoS2:MIL-53 (Fe) prepared by holding at 150 °C for 10 h was 0.20:1 (20%MSMF). In the adsorption-photocatalytic synergy experiment, 87.62% of tetracycline (30 mg/L) could be removed with 0.20 g/L of 20%MSMF after 40 min of UV irradiation, while the removal of tetracycline by MoS2 and MIL-53 (Fe) was only 35.99% and 65.40%. The characterization showed that the specific surface area and total pore volume of 20%MSMF were 1.12 and 3.12 times higher than those of MIL-53 (Fe), respectively. And the separation and transfer efficiency of electron–hole pairs were improved for 20%MSMF compared to the constituent components. These results suggest that the doping of MoS2 enhances the adsorption and photocatalytic ability of MIL-53 (Fe) that can be used for the efficient treatment of tetracycline. [ABSTRACT FROM AUTHOR]

Bi-based catalysts can efficiently remove organic pollutants from the environment, but their performance still needs to be improved. Herein, BiOBr photocatalyst was prepared by one-step hydrothermal method, with bismuth nitrate and hexadecyl trimethyl ammonium bromide (CTAB) as precursors, and then BiOBr was transformed to Bi2O2CO3 by the doping of urea. The structure and properties of the photocatalysts were characterized by SEM, TEM, XRD, XPS, UV–Vis, and BET, and the photocatalyst was used for the degradation of BPA. The results showed that the most economical doping amount of urea was 3 g, and the degradation rate of 10 mg/L BPA was 92.01% within 30 min at the catalyst dosage of 0.8 g/L, which was 1.98 times higher than that of pure BiOBr. The quenching experiments and ESR characterization indicated that · O 2 - , h+ and ·OH were involved in the photocatalytic process, among which, the effect of · O 2 - was stronger than that of the other two active substances. Moreover, the degradation rate of BPA was still above 80% after four cycles, indicating that this photocatalyst is a highly efficient and stable material, which is expected to be applied in the environmental treatment and human health. [ABSTRACT FROM AUTHOR]

In this study, Bi2Ti2O7−TiO2 was synthesized in a single step via the sol–gel method, after which its photocatalytic properties and mechanisms were investigated. Moreover, our study proposed and evaluated the use of salicylic acid (SA) and basic magenta (BM) as model contaminants in quenching experiments. When SA was used as the model pollutant, the reaction rates showed negative values. Therefore, the experimental results failed to truly and effectively reflect the actual photocatalytic performance of Bi2Ti2O7−TiO2. However, when BM was used as the model pollutant, the reaction rates were all positive and the experimental results were far more descriptive. Hydroxyl radicals (·OH), superoxide radicals (·O2−), and photogenerated holes (h+) all contribute to the photocatalytic activity of Bi2Ti2O7-TiO2, with ·OH making the largest contribution. Collectively, our findings can serve as a basis to improve the accuracy and efficiency of future photocatalytic mechanism experiments, which could bring great economic benefits. [ABSTRACT FROM AUTHOR]