Preparation of heterostructured Ag@AgCl/La2Ti2O7 plasmonic photocatalysts with high visible light photocatalytic performance for the degradation of organic pollutants

Abstract

In this work, Ag@AgCl modified La₂Ti₂O₇ plasmonic photocatalysts were prepared by a simple and feasible two-step process. The prepared samples were characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectrometry (DRS), photoluminescence (PL). Methylene blue (MB), rhodamine B (RhB), reactive brilliant red X-3B (X-3B) and phenol were used as model organic pollutants to investigate the photocatalytic activity of the as-prepared samples under visible light irradiation. The high photocatalytic activity of Ag@AgCl/La₂Ti₂O₇ could be attributed to the surface plasmon resonance (SPR) effects of Ag and the formation of a heterostructure between Ag, AgCl and La₂Ti₂O₇, which effectively suppresses the recombination rate of the photogenerated electron–hole pairs. The cycling experiments revealed the good stability of the Ag@AgCl/La₂Ti₂O₇ composites. Furthermore, the possible photocatalytic mechanisms were also proposed. It would provide a potentially new composite photocatalyst for environment remediation.