Enhanced photocatalytic degradation of antibiotic drug and dye pollutants by graphene-ordered mesoporous silica (SBA 15)/TiO2 nanocomposite under visible-light irradiation

Currently, a growing trend in wastewater treatment research focuses on the generation and release of reactive oxygen species (ROS) on the surface of mesoporous Graphene-SBA/TiO2 photocatalyst. Herein, we addressed the disadvantages of TiO2 nanoparticle and develop the applicability of the mesoporous Graphene-SBA/TiO2 nanocomposite's photocatalytic activity. Graphene-SBA/TiO2 photocatalysts synthesized with varying graphene loading (1, 3, and 5 wt%) were characterized by SAXRD, WAXRD, FTIR, RAMAN, EDAX, HRTEM, UV-Vis, BET, and XPS. The photocatalytic effectiveness of the Graphene-SBA/TiO2 nanocomposites was tested under visible light irradiation using TC (Tetracycline) antibiotic drugs and MB (Methylene blue) dye dissolved in water as the pollutant. The outcomes revealed that about 98% of MB and 89% of TC drug was photodegraded under visible light irradiation within 30 min and 60 min, respectively. The photocatalytic degradation of MB and TC drug followed a pseudo-first-order reaction kinetics with an apparent rate constant of 0.1189 min(-1) and 0.0367 min(-1), correspondingly. In comparison with the SBA/TiO2 nanocomposite, it demonstrates an excellent potential to adsorb aromatic compounds via pi-pi stacking. The improved photocatalytic activity was attributable to the presence of graphene. The mechanism has also been described: the excellent photo-degradation effect of the MB dye and the TC drug pollutants by the Graphene-SBA/TiO2 was owed to the synergetic (interfacial) effect of the graphene sheets and the SBA/TiO2. The SBA/TiO2 served as the migration media for the visible light-developed charge carriers, while the graphene sheet improved the photocatalytic due to the large surface area and the number of active sites. The robustness experiments demonstrated the Graphene-SBA/TiO2's anti-photo erosion potential. The Graphene-SBA/TiO2 nanocomposite proved to be a promising candidate as a water purification technology. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The mesoporous Graphene-SBA/TiO2 nanocomposites exhibit excellent photocatalytic activity in degrading pollutants in water under visible light irradiation, showing promising potential for water purification technologies.