Efficient photocatalytic degradation of organic dyes and reaction mechanism with Ag2CO3/Bi2O2CO3 photocatalyst under visible light irradiation

Abstract Hierarchical Ag 2 CO 3 /Bi 2 O 2 CO 3 microflowers were synthesized at room temperature using a facile solution method. The as-prepared composite was composed of numerous two-dimensional nanosheets with oriented terminal arrangement. The photocatalytic activities of Bi 2 O 2 CO 3 , Ag 2 CO 3 and Ag 2 CO 3 /Bi 2 O 2 CO 3 were evaluated through the photodegradation of wastewater which contains organic dyes of rhodamine B (RhB), methyl orange (MO), methylene blue (MB), or their mixture under visible light irradiation (λ ≥ 420 nm). Results showed that the photocatalytic activity of Ag2CO3/Bi2O2CO3 was much higher than that of single phase Bi2O2CO3 or Ag2CO3. In addition, the Ag2CO3/Bi2O2CO3 photocatalyst also showed good photostability and recyclability. The excellent photocatalytic efficiency of the Ag2CO3/Bi2O2CO3 photocatalyst could be ascribed to the improved light absorption ability and the reduced recombination of photo-generated electron-hole pairs during photocatalytic reactions. Moreover, the possible transferred and separated behavior of electron-hole pairs and photocatalytic reaction mechanism on the Ag2CO3/Bi2O2CO3 photacatalyst are illustrated in detail.