Nanoarchitectonics of AgBr/4A Zeolite Composites with Enhanced Photocatalytic Properties Under Visible Light

Abstract

AgBr/zeolite photocatalysts with different mass ratios were synthesized by depositing AgBr on the surface of 4A zeolite via the one-step precipitation method. AgBr/zeolite with mass ratios of 1:1 exhibited the highest photocatalytic activity, resulting in the complete degradation of the methyl orange (MO) dye under visible-light irradiation for 30[Formula: see text]min. The photocatalysts were characterized by N2 adsorption–desorption, scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–Vis diffused reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy. The AgBr particles around 4A zeolite were smaller than pure AgBr. The specific surface area of 1:1 AgBr/zeolite was much larger than that of pure AgBr, which indicates that 1:1 AgBr/zeolite possessed more active sites. The photocatalytic stability of 1:1 AgBr/zeolite was investigated, and MO degradation rate of 90.4% was achieved after five cycling runs. The trapping experiments showed that hydroxyl radical ([Formula: see text]OH), superoxide radical ([Formula: see text]), and hole (h+) were the reactive species responsible for removing MO, and h+ played a key role in MO removal. A possible reaction mechanism in AgBr/zeolite photocatalytic system for MO degradation was proposed.