Fabrication and investigation on Ag nanowires/TiO 2 nanosheets/graphene hybrid nanocomposite and its water treatment performance

In this paper, a novel Ag nanowires/TiO 2 nanosheets/graphene nanocomposite was fabricated via a facile method of hydrothermal and calcination, and then the water treatment performance of it was evaluated for methylene blue (MB) and Escherichia coli removal. The as-prepared Ag nanowires/TiO 2 nanosheets/graphene nanocomposite was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), UV–visible diffuse reflection spectroscopy (DRS), molecular dynamics simulation, and gas chromatography–mass spectrometry (GC-MS). All data revealed that the Ag/TiO 2 /graphene nanocomposite showed a rich cell structure. The photocatalytic activity of Ag/TiO 2 /graphene nanocomposite is higher than those of pristine TiO 2 nanosheets and TiO 2 /graphene nanocomposite. Under optimized conditions, the degradation efficiency was 100% and 71% for MB (30 mg/L) and with 10 mg Ag/TiO 2 /graphene nanocomposite under UV and visible light irradiation for 2 h, respectively. Ag/TiO 2 /graphene also showed excellent bacteria-killing activity. Meanwhile, the Ag/TiO 2 /graphene nanocomposite exhibited microstructure stability and cyclic stability. The water treatment performance was enhanced mainly attributed to the excellent adsorption performance of graphene and the high efficiency in separation of electron–hole pairs induced by the remarkable synergistic effects of TiO 2 , Ag, and graphene. On the basis of the experimental results, the photocatalytic mechanism and MB degradation mechanism were proposed. It is hoped that our work could avert the misleading message to the readership, hence offering a valuable source of reference on fabricating composite photocatalyst with stable microstructure and excellent performance for their application in the environment clean-up. Graphical abstract