Universal degradation performance of a high-efficiency AgBr/Ag 2 CO 3 photocatalyst under visible light and an insight into the reaction mechanism

• Published in: New journal of chemistry 2015, Vol.39 (6), p.4891-4900
• Main Authors: Yin, Lu, Wang, Zhen, Lu, Lian, Wan, Xiankai, Shi, Huixiang
• Format: Article
• Language: English
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/C5NJ00385G

A high-efficiency visible light-driven AgBr/Ag 2 CO 3 photocatalyst has been synthesized via a simple ion-exchange method. The textural, morphological and optical properties of the photocatalyst were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption–desorption isothermal measurement and UV-vis diffuse reflectance spectroscopy (DRS). The prepared composite exhibited excellent photocatalytic efficiency for the degradation of methyl orange (MO), tetracycline (TC) and bisphenol A (BPA) under visible light irradiation ( λ > 420 nm). Compared to pure Ag 2 CO 3 , AgBr/Ag 2 CO 3 exhibited considerably higher photocatalytic activity and stability. The quenching effects of different scavengers and electron spin resonance (ESR) analysis suggest that holes and ˙O 2 − were the main reactive species responsible for the pollutant degradation and holes played the leading role. Two electron reaction processes were verified in the AgBr/Ag 2 CO 3 photocatalytic system on the basis of ESR and X-ray photoelectron spectroscopy (XPS). Thus, a two-stage photocatalytic mechanism was proposed.