Compare the photocatalytic properties of nanocomposites with tandem n (AgBr)-n (Ag2CO3) and p (AgCl)-n (Ag2CO3) heterojunctions

Abstract

In this work, Ag2CO3 nanoparticles (NPs) (as a n-type semiconductor) incorporated in mordenite zeolite (MOR) by a facile precipitation method. Silver halides, AgCl (as a p-type semiconductor) and AgBr (as a n-type semiconductor), with different weight percentage (20%, 40% and 50%) were coupled into Ag2CO3-MOR nanocomposite (NC) and producing a series of novel AgCl/Ag2CO3 (p-n heterojunction)-MOR and AgBr/Ag2CO3 (n-n heterojunction)-MOR NCs. The effects of silver halides on the Ag2CO3–MOR catalyst for the photocatalytic degradation of methyl blue (MB) under visible light irradiation have been investigated. The structure, composition and optical properties of NCs were investigated by UV–Visible diffuse reflectance spectroscopy (UV–Vis DRS), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM). The prepared AgX/Ag2CO3-MOR NCs with the optimal content of AgX (50wt%) indicated higher photocatalytic activity than that of the Ag2CO3-MOR and Ag2CO3. The cycle experiments on the heterojuctions NCs indicated that photocatalytic stability of AgBr/Ag2CO3-MOR NC was more than AgCl/Ag2CO3-MOR NC in all cycles. On the basis of the experimental results, a possible mechanism for the enhanced photocatalytic activity and photoinduced stability of silver compounds was proposed.