A plasmonic photocatalyst of Ag@AgBr/La2Ti2O7 with enhanced photocatalytic activity under visible light irradiation

In this paper, a plasmonic photocatalyst of Ag@AgBr/La2Ti2O7 was synthesized through a chemical precipitation method followed by a photoreduction process. The crystallinity, morphology, chemical composition, and optical properties of the as-prepared samples were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectrum. The photocatalytic activity of the samples was investigated toward the degradation of rhodamine B (RhB) under visible light irradiation. Among the obtained photocatalysts, Ag@AgBr/La2Ti2O7 displayed the highest photocatalytic activity, degrading approximate 98% of RhB within 8 min of visible light illumination. The superior photocatalytic activity of Ag@AgBr/La2Ti2O7 was attributed to the formation of heterojunctions between Ag@AgBr and La2Ti2O7 as well as the surface plasmon resonance effect of Ag nanoparticles (NPs), which would be conducive to the efficient separation of photogenerated electrons and holes. The active species trapping experiments indicated that center dot O-2(-) and h(+) were the main reactive species responsible for RhB degradation. Furthermore, a possible photocatalytic mechanism for RhB decomposition over Ag@AgBr/La2Ti2O7 was proposed.

Automated summary

A plasmonic photocatalyst of Ag@AgBr/La2Ti2O7 was synthesized and showed excellent photocatalytic activity, with the formation of heterojunctions between Ag@AgBr and La2Ti2O7 contributing to efficient separation of photogenerated electrons and holes. The main reactive species responsible for RhB degradation were identified as center dot O-2(-) and h(+), and a possible photocatalytic mechanism for RhB decomposition over this catalyst was proposed.