Preparation of magnesium aminoclay-carbon dots/TiO2 as photocatalysts for wastewater management

Abstract

Magnesium aminoclay (MgAC) has been used to remove different harmful pollutants from the environment. In this study, MgAC was successfully converted into MgAC-carbon dots (MgAC-CDs) using microwave radiation, which was then used to prepare MgAC-CDs/TiO2 composites for use in water treatment. Pure TiO2, MgAC-CDs, and MgAC-CDs/TiO2 were investigated via X-ray powder diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller theory, and photoluminescence. Through these techniques, the presence of MgAC-CDs decreased the size of TiO2, and the interaction between TiO2 and MgAC-CDs led to the formation of vacant oxygen in TiO2. MgAC-CDs [0.20 g]/TiO2 had the best photocatalytic performance in the ultraviolet spectrum/light-emitting diode (LED, in visible spectrum) among all MgAC-CDs/TiO2 composites. Preliminary data indicate that a concentration of 1 mg/mL can inactivate an MS2 bacteriophage in 1 h of irradiation under ultraviolet light or LEDs. The high photocatalytic performances of MgAC-CDs/TiO2 can be explained by interactions between MgAC-CDs and TiO2, which forms a layer of vacant oxygen, and also by the remaining MgAC sheet, which contributes to the high specific surface area.