Environmentally Friendly Synthesis: Photocatalytic Dye Degradation and Bacteria Inactivation Using Ag/f-MWCNTs Composite

In this study, silver nanoparticles (AgNPs) were decorated onto functionalized carbon nanotubes (Ag/f-MWCNTs) using a green method under sunlight conditions. The as-synthesized composite was characterized by UV–vis spectroscopy, XRD, FTIR, SEM, and TEM microscopy. In Ag/f-MWCNTs composite, synthesized NPs were spherically shaped, with particle size ranging from 17.1 to 30.5 nm. The photocatalytic degradation activity of Ag/f-MWCNTs composite was evaluated for the degradation of the cationic methylene blue (MB) dye solution. The rate constants for photocatalytic dye degradation were 0.012 and 0.051 min−1 for f-MWCNT and Ag/f-MWCNTs respectively. Compared with that of f-MWCNTs, Ag/f-MWCNTs composite showed high dye degradation activity after irradiation for 60 min. In addition, photocatalytic bacterial inhibition was studied for the gram-negative bacterium Escherichia coli at different time intervals under visible light irradiation. Ag/f-MWCNTs exhibited maximum photocatalytic bacteria inactivation after 120 min. Based on the obtained results, Ag/f-MWCNTs are a tremendously efficient photocatalyst for the degradation of toxic dyes and bacteria inactivation, and the synthesized material serves as an efficient component for wastewater treatment.