Efficient Adsorption and Photocatalytic Degradation of Dyes by AgI-Bi2MoO6/Vermiculite Composite under Visible Light

A novel efficient AgI-Bi2MoO6/vermiculite adsorption-photocatalyst is successfully synthesized by sol-gel method and precipitation method. The structure and properties of AgI-Bi2MoO6/vermiculite were analyzed by XRD, FT-IR, XPS, SEM, TEM, BET, and DRS. All the AgI-Bi2MoO6/vermiculite composites with different AgI content show enhanced photocatalytic performance for malachite green (MG) dye degradation compared to pure Bi2MoO6 and Bi2MoO6/vermiculite composites. The highest degradation efficiency for MG (30mg/L) via 5wt%-AgI-Bi2MoO6/vermiculite composite (AgI content 5wt%) photocatalyst (1g/L) reaches 98.89% in 60min at pH9 without salt. The enhanced performance can be attributed to the uniform dispersion of Bi2MoO6 and AgI on the surface of vermiculite, the stable structure, the enhanced adsorption and the widened visible-light absorption range as well as the faster separation of electron-hole pairs. Besides, the photocatalyst still shows relatively high adsorption and photocatalytic performance after three times recycling. In addition, the possible photocatalytic mechanism is proposed at the end.