One-step fabrication of novel MIL-53(Fe, Al) for synergistic adsorption-photocatalytic degradation of tetracycline.

Bimetallic MOFs (MIL-53 (Fe, Al)) were successfully fabricated via a facile one-step solvothermal method for the removal of tetracycline (TC) from aqueous solutions. Tetracycline adsorption and photocatalytic experiments indicate that the optimum bimetallic synthetic molar ratio is 3:2 (40%MIL-53(Fe, Al)). The adsorption data are well fitted by the Freundlich model and pseudo-second-order adsorption kinetics. 40%MIL-53(Fe, Al) has an adsorption capacity of up to 402.033 mg/g. After the dark adsorption phase, 10 mg of 40%MIL-53(Fe, Al) can remove 94.33% of the tetracycline in a 70 mL aqueous solution (20 mg/L) under 50 min irradiation, while only 71.39% and 81.82% of the tetracycline are removed by MIL-53(Fe) and MIL-53(Al) under the same conditions. In addition, 40%MIL-53(Fe, Al) exhibits a significant adsorption-photocatalytic synergy (under direct irradiation without a dark adsorption phase), in which the pseudo-first-order kinetic constant increases by a factor of 3.11. Quenching experiments and ESR characterization indicate that ·O2-, ·OH, and h+ are the main active species in the photocatalytic process. Meanwhile, 40%MIL-53(Fe, Al) demonstrates good stability, with a tetracycline removal rate that still reaches 83.70% after 4 cycles. These results suggest that the prepared 40%MIL-53(Fe, Al) catalyst is a novel adsorption-photocatalytic material that can be used for the efficient treatment of tetracycline.

Chen X ，Liu X ，Zhu L ，Tao X ，Wang X ... -  《-》

MoS(2)-modified MIL-53(Fe) for synergistic adsorption-photocatalytic degradation of tetracycline.

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.

Zhu L ，Chen Y ，Liu X ，Si Y ，Tang Y ，Wang X ... -  《-》

Simultaneously efficient adsorption and photocatalytic degradation of tetracycline by Fe-based MOFs.

Recently, Fe-based metal-organic frameworks (MOFs) have attracted increasing attention and been widely used. To date, however, it is unknown whether they can be employed to degrade tetracycline, one of the most widely used antibiotics. This work therefore aims to provide such support by comparing the performance of three Fe-based MOFs (namely, Fe-MIL-101, Fe-MIL-100, and Fe-MIL-53) in removing tetracycline. Experimental results showed that Fe-MIL-101 exhibited the best performance in tetracycline removal, with 96.6% of tetracycline being removed (initial tetracycline concentration at 50 mg/L) while Fe-MIL-100 and Fe-MIL-53 removed 57.4% and 40.6% under the same conditions. Additionally, the effects of adding dosage, adsorption time, and initial concentration of tetracycline on degradation efficiency were examined. It was found that the adsorption and photocatalytic degradation effect was better with the increase of time, the optimum dosage of Fe-MIL-101 was 0.5 g/L and the removal efficiency decreased with the increasing of initial tetracycline concentrations. Moreover, the trapping experiments and ESR tests indicated that O2-, OH and h+ were the main active species in photocatalytic degradation process of tetracycline. Due to its high removal efficiency and simple synthesis, it could be used as a potential catalyst for degradation of tetracycline and other antibiotics.

Wang D ，Jia F ，Wang H ，Chen F ，Fang Y ，Dong W ，Zeng G ，Li X ，Yang Q ，Yuan X ... -  《-》

Modular Construction of an MIL-101(Fe)@MIL-100(Fe) Dual-Compartment Nanoreactor and Its Boosted Photocatalytic Activity toward Tetracycline.

Jin Y ，Mi X ，Qian J ，Ma N ，Dai W ... -  《-》

Three-dimensional porous La(OH)(3)/g-C(3)N(4) adsorption-photocatalytic synergistic removal of tetracycline.

La(OH)3/g-C3N4 composites were successfully synthesized via one-step calcination using urea, melamine, and La(NO3)3·nH2O as raw materials, and applied to UV-induced photocatalytic tetracycline (TC) removal. Comprehensive characterization by an X-ray diffraction (XRD), Fourier transform infrared reflection (FT-IR), high-resolution transmission electron microscope (HRTEM), and other techniques analyzed effects of La3+ doping, especially N vacancies and cyano groups as active sites. Compared to pure g-C3N4 and La(OH)3, synthesized La(OH)3/g-C3N4 composites exhibited a three-dimensional porous nanosheet structure with specific surface area of 83.62 m2/g and equilibrium TC adsorption capacity up to 285.59 mg/g; La(OH)3 doping significantly improved composite structure. After dispersing 10 mg La-CN-0.5 photocatalyst in 60 mL 40 mg/L TC solution, TC removal reached 91.08% in 30 min under UV irradiation, exhibiting excellent performance. Additionally, La-CN-0.5 showed significant adsorption-photocatalytic synergism, with the quasi-primary kinetic constant increased by 1.83-fold. The efficiency of high tetracycline (TC) concentration treatment through adsorption photocatalytic degradation by La-CN-0.5 was confirmed by the utilization of free radical trapping and electron spin resonance (ESR) tests. The significant involvement of ∙O2-, ∙OH, and h+ in this process was observed. These findings propose that the prepared La-CN-0.5 material exhibits a unique capability for adsorption photocatalysis, providing a promising approach for the efficient removal of high TC concentrations.

Wang B ，Liu X ，Liu B ，Huang Z ，Zhu L ，Wang X ... -  《-》