A facile approach is developed to synthesis the highly efficient photocatalyst of Bi2O2CO3/BiOCl. The composite of Bi2O2CO3/BiOCl exhibits excellent photocatalytic activity toward Rhodamine B (RhB) under visible light, which is even better than that of P25 (commercial TiO2) under UV light. The role of the active species in the process of the degradation is evaluated by using different types of active species scavengers and measurement of electron spin resonance (ESR). The relative band structures of the Bi2O2CO3 and BiOCI are determined combined with the flat potential (Vs,) and bandgap energy (Eg) evaluated by UV-vis diffuse reflectance spectra. The results show that the composite of the two semiconductors facilitates the photosensitized degradation of RhB under visible light (420 nm< X< 800 nm). And the essence of RhB photosensitization is revealed to.be the increase of H2O2 in the reaction system. The photocatalytic mechanism is further proposed, which unfolds the charge transfer and the active species formed in the photcatalytic process. The work may set foundation for application of the new photocatalyst of Bi(2)O(2)CO(3-)based heterostructure. (C) 2016 Elsevier B.V. All rights reserved.