Facile Synthesis of Ag@AgCl Plasmonic Photocatalyst and Its Photocatalytic Degradation under Visible Light

A facile synthesis for Ag@AgCl plasmonic photocatalysts with high photocatalytic efficiency of organic pollutants under visible light was done by the precipitation-visible light irradiation method. The sample was characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectra (DRS), and X-ray photoelectron spectroscopy (XPS). Photocatalytic degradation of methyl orange (MO) was carried out to evaluate the photocatalytic activity of Ag@AgCl under visible light irradiation. It is found that the Ag@AgCl photocatalyst shows a strong absorption in the visible region, which is attributed to the plasmon resonance of silver NPs deposited on AgCl particles. The photocatalytic reaction parameters, such as photoreduction time, dosage of catalyst and pH value were studied and optimized, and the highest activity for the degradation of methyl orange is up to 83% in 120 min under visible light irradiation. The excellent visible light photocatalytic activity can be attributed to the surface plasmon resonance effect of Ag NPs anchored on AgCl particles. The mechanism of separation of the photogenerated electrons and holes at the Ag@AgCl photocatalyst were discussed.