Improved photocatalytic activity of Ag2S quantum dots decorated TiO2 nanotubes under visible light

In this paper, Ag2S quantum dots (QDs) are successfully synthesized through a wet chemical method. Additionally, a hydrothermal method is employed to prepare Ag2S QDs decorated TiO2 nanotubes (Ag2S@TNT) from Ag2S decorated TiO2 (Ag2S@TiO2). Furthermore, fluorescence spectroscopy (FL) is conducted to observe a substantial quantum confinement effect induced by Ag2S QDs. The average particle size of Ag2S@TNT is measured as 0.53 nm, as depicted in the high-resolution transmission electron microscopy (HR-TEM) images. The Brunauer-Emmett-Teller (BET) surface area analysis technique is utilized to assess the pore volume and surface area of the synthesized material. The electrochemical impedance spectra (EIS) analysis revealed that Ag2S@TNT exhibited the smallest arc radius, signifying superior transfer and separation efficiency for photo-excited carriers compared to other samples. The photocatalytic degradation study demonstrates that Ag2S@TNT exhibits impressive photocatalytic activity and stability in the presence of methylene blue (MB) as the target organic pollutant under simulated visible light.