Surface acid etching of (BiO)2CO3 to construct (BiO)2CO3/BiOX (X = Cl, Br, I) heterostructure for methyl orange removal under visible light

A series of (BiO)2CO3/BiOX (X = Cl, Br, I) heterostructured photocatalysts were synthesized through acid etching method and characterized by XRD, DRS, SEM and HRTEM, respectively. Under visible light (λ > 400 nm), (BiO)2CO3/BiOX displayed much higher photocatalytic activity than pure (BiO)2CO3 and corresponding BiOX for the degradation of methyl orange (MO). The photocatalytic activities of the as-prepared samples increased following this order: (BiO)2CO3/BiOCl < (BiO)2CO3/BiOBr < (BiO)2CO3/BiOI. The enhanced photocatalytic activities could be attributed to the function of heterojunction interface between (BiO)2CO3 and BiOX. Moreover, except for the role of heterostructure, the excellent photocatalytic performance of (BiO)2CO3/BiOI also originated from its good visible light absorption.