Methylene blue degradation under visible light of Au-DP25/PET and Cu-DP25/PET photocatalytic films, synthesized through two wet impregnation routes – An experimental and theoretical evaluation

Abstract

Two wet impregnation methods (W-I and W-II) were employed to develop Cu-DP25/PET and Au-DP25/PET photocatalytic films. The W-I method based on the synthesis of M-TiO2 powders (DP25 decorated with metal) followed by the sono-deposition on PET sheets. The W-II method begins with the sono-deposition of DP25 onto PET sheets, followed by the sono-deposition of M-TiO2 solution (DP25 +Metal+H2O). Under visible light, the Cu-DP25/PET and Au-DP25/PET films via W-II exhibited superior photocatalytic activity. The photocatalytic activity was studied by analyzing the degradation of methylene blue (MB) under visible light. The materials were characterized with the employing of scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis DRS (UV–Vis) spectroscopy, and photoluminescence (PL). The interactions between catalysts/environment were studied through molecular dynamics simulation (MD) and binding energies (Ebinding). The superior photodegradation of Au-DP25/PET films towards MB was attributed to the combination of two effects: LSPR (localized surface plasmon resonance) and Au-TiO2/environment affinities. The aim of the experimental/theoretical analysis was to provide a deep understanding of the medium/surface interactions on decorated TiO2 materials and how these interactions influence the overall degradation behavior.