In this work, a series of (BiO)(2)CO3 photocatalysts were successfully fabricated using a hydrothermal method by adjusting the molar ratio of Bi(NO3)(3)center dot 5H(2) O and urea (Bi/C). The results demonstrate that the molar ratio of Bi(NO3)(3)center dot 5H(2)O and urea (Bi/C) can significantly influence the samples obtained and the corresponding photocatalytic performance. When Bi/C is between 1/4 and 1/7, (BiO)(2)CO3 was successfully obtained. Furthermore, the molar ratio of Bi/C can affect the separation rate of photo-induced charge pairs, confirmed by results of surface photovoltage spectroscopy (SPS). The photocatalytic activities of the as-obtained samples were tested using methyl orange (MO) as a target pollutant. The results reveal that the sample prepared with 1/5 molar ratio of Bi/C exhibits the highest photocatalytic activity under simulated sunlight irradiation, which can be tightly attributed to its higher photo-generated carriers separation efficiency than other samples.