Preparation and application of α-Fe2O3@MIL-101(Cr)@TiO2 based on metal-organic framework for photocatalytic degradation of paraquat.

In this study, a new magnetic α-Fe2O3@MIL-101(Cr)@TiO2 photocatalyst was successfully synthesized. The material synthesized had been fully characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and Brunauer-Emmett-Teller isotherm methods. The X-ray diffraction analysis corroborates that nanoparticles are polycrystalline with rhombohedral and tetragonal crystal structures for Fe2O3 and TiO2, respectively. In addition, the photocatalytic degradation of the herbicide paraquat in the presence of α-Fe2O3@MIL-101(Cr)@TiO2 under ultraviolet (UV) irradiation was studied. The effect of experimental parameters such as the initial concentration of catalyst, the pH, and the initial paraquat was investigated. The optimal conditions were achieved for concentration of catalyst 0.2 g L-1, pH 7, and concentration of paraquat 20 mg L-1. The photocatalytic degradation efficiency was 88.39% after 15 min with α-Fe2O3@MIL-101(Cr)@TiO2 under UV irradiation. The pseudo-second-order kinetic model for photocatalytic degradation of paraquat was obtained. The catalysts could be recovered and reused without any loss of efficiency for five times in the consequent reactions. To the best of our knowledge, this is the first report on the photocatalytic degradation of paraquat using new α-Fe2O3@MIL-101(Cr)@TiO2 photocatalyst under UV irradiation condition.

Synthesis and characterization of an NH4CL-induced Eskanbil activated carbon (EAC) for the removal of penicillin G from contaminated water.

Penicillin G (PG) is one of the most widely used antibiotics around the world. The release of PG in an aqueous solution leads to contamination of water resources. This study aimed to determine the efficiency of modified Eskanbil activated carbon for the removal of PG from aqueous solutions. The NH4Cl-induced activated carbon was synthesized by a simple method and used for the degradation of PG in contaminated water. Activated carbon was characterized by Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), and Brunauer-Emmett-Teller (BET) surface area analysis. The four main reaction parameters optimized in this study were pH, time, the concentration of the EAC (Eskanbil Activated Carbon), and initial PG concentration. The synthesized carbon was characterized and the results showed it as a mesoporous material with the BET specific surface area of 1473 m2/g and pore volume of 0.81 cm3/g. The maximum PG adsorption onto EAC was observed at the pH of 6. The PG removal of 33% at an EAC concentration of 0.1 g/L increased to 99.98% at an activated carbon concentration of 0.5 g/L. The isotherm and kinetic studies of PG removal by EAC showed that the Freundlich model (R2 > 0.995) and the pseudo-second-order (R2 > 0.983) equation represented the best fit with the adsorption data. EAC is recommended as a suitable and cost-efficient adsorbent for removing poisons, pharmaceuticals, and other emerging contaminants from water resources.