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

Abstract

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 π–π 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.